How to Defrost an RV Refrigerator in 20 Minutes!

Defrosting an RV refrigerator is a surprisingly easy job. We’ve been living with a propane RV refrigerator for many years now, and they always need defrosting after a few weeks or months. Being meticulous about not leaving the refrigerator door open unnecessarily can help, but when you find yourself living in a hot and humid environment or if you have the refrigerator side of your trailer or motorhome facing the blazing hot summer sun all afternoon, the frost is going to build up over time.

All you need to defrost an RV refrigerator is:

Over the years, we’ve tried several different techniques for defrosting our RV fridge, and in the old days this was a big job that, with some methods, could take well over an hour. We now have it down to a super fast method that makes this pesky job a cinch. The last time we did it, I made a note of the time on the clock as we went through each step. From start to finish, it took 20 minutes.

The first step is to turn off the refrigerator and empty the contents of the freezer into cooler bags or a cooler of some kind. Since these things will be out of the freezer for just 20 minutes, they won’t defrost and the ice cream won’t melt. If your RV is hot inside, covering the cooler bags with blankets for extra insulation can help.

Defrost RV refrigerator remove food from freezer

9:17 a.m. – Turn off fridge and unload freezer into cooler bags

We used to unload the whole refrigerator and empty it out completely, but that isn’t necessary and it takes a lot of time. An awful lot of what is in the refrigerator can handle warming up slightly as you keep the refrigerator door open to defrost it.

Instead, just unload the most temperature sensitive items — milk, yogurt, lunch meats, mayonaise, etc., into an insulated cooler bag or a cooler. Most of the fruits, veggies, bread, cheese, condiments, etc., can remain right where they are in the fridge for the 20 minutes it takes to defrost it.

How to defrost an RV fridge with food in cooler bag

Set the cooler bags aside. Covering them with blankets will keep everything even cooler.

Next, put a super absorbant chamois towel in the bottom of the freezer compartment to absorb the water from the melting ice, and use a hair dryer to thaw the walls of the freezer.

Defrosting RV refrigerator hair dryer on freezer with towels

9:22 a.m. – Use a hair dryer to thaw out the freezer.

We live exclusively on solar power, and our 2,000 watt pure sine wave inverter is what powers all our AC appliances, including the hair dryer. So, we have a low wattage travel hair dryer that draws just 800 watts (available here).

We put it on the high setting and keep a distance of about 8″ between the hair dryer and the walls of the freezer. A higher wattage hair dryer may need to be put on the low heat setting. Hold your hand about 8″ from the hair dryer and see how hot it feels.

Be sure you keep the hair dryer from heating up the plastic walls or they will crack from being cold and then getting hot. Keep the hair dryer moving and test the temp of the plastic walls with your hands.

After thawing the walls of the freezer a little, move down to the cooling fins in the refrigerator compartment. Keep the hair dryer in constant motion, sweeping it back and forth from side to side.

Defrost RV refrigerator hair dryer on cooling fins

Slowly wave the hair dryer in front of the cooling fins.

Alternate working on the freezer compartment and the refrigerator compartment.

How to defrost an RV refrigerator hair dryer in freezer

Alternate between the cooling fins in the refrigerator compartment and the freezer compartment.

Defrosting RV refrigerator hair dryer on fridge cooling fins

At the beginning, when the cooling fins are caked in ice, the hair dryer can be closer to them.

Little ice sheets will begin to fall off the refrigerator cooling fins into the drip tray underneath. As the thawing process continues, increase the distance between the hair dryer and the cooling fins.

How to defrost an RV fridge melting ice with hair dryer

As ice drops and the cooling fins thaw, move the hair dryer back a little.

Don’t chisel the ice off the fins or the freezer walls with a tool. If you pierce the metal base behind the cooling fins or the walls of the freezer, the refrigerant (ammonia) will leak out. We don’t use any chiseling device. We simply assist the thawing process with the hair dryer.

Check beneath the cooling fins and you’ll see the bits of ice dropping into the drip tray.

How to defrost an RV refrigerator ice dropping from fridge cooling fins

Check below the cooling fins where the ice drops off in chunks.

If you go outside, on the back of the RV you’ll see water seeping out of the refrigerator vent.

How to defrost an RV fridge water dripping from refrigerator vent on outside of trailer

Outside the rig, water will be seeping from the refrigerator vent.

How to defrost an RV refrigerator water dripping down fridge vent outside trailer

A little trickle of water flows down.

Once all the ice has fallen off the cooling fins, pull out the drip tray and dump the ice in the sink.

Ice in RV refrigerator drip tray

9:34 a.m. – Once all the ice has dropped off the cooling fins, empty the tray of ice into the sink.

Up in the freezer compartment, the chamois towel is now fairly wet with water that has dripped down off the walls. Wring it out and use it to wipe down the freezer and the fridge.

Wet Chamois towel from defrosting RV refrigerator

9:35 a.m. – The chamois towel in the freezer is pretty wet. Use it to wipe down the fridge and freezer.

Load the food from the cooler bags back into the refrigerator and freezer compartments, and you’re done! Put the fridge at max temp for a few hours to help it cool back down, and then set it to the temperature setting you normally use.

Defrosted RV refrigerator

9:37 a.m. – After loading the food back in the refrigerator, turn it back on. Done!

Other RV Refrigerator Tips

The key to having an RV refrigerator work optimally is having the air circulate inside well. Overstuffing the fridge with food makes this difficult for it. We have used a little RV refrigerator airator fan that’s designed to keep the air flowing. We’ve had mixed results with this, and when it died we didn’t replace it. I think this would work well if there were space between all the food, but our fridge is usually packed (the turf wars between the beer and the veggies can be brutal…sometimes we can hear them battling it out in there!).

As a maintenance item, we keep the door seals clean, wiping them down periodically.

We use simple refrigerator thermometers to monitor the temperatures in the fridge and freezer. It has a built in hook, and we hang it from one of the rungs in the top shelf in the refrigerator. The one in the freezer rests against one wall.

We were surprised to learn that RV refrigerators have an expected lifespan of about 8 to 10 years. A classic sign of impending failure is the appearance of yellow dust in the refrigerator vent area behind the fridge (go outside and take the vent cover off and look around with a flashlight). Click the following link to read the funny story of our RV refrigerator replacement and see how an RV fridge replacement is done.

Because of the shorter lifespan, higher price, and use of propane in RV refrigerators, many (most) “full-time” level fifth wheels and motorhomes are now being built with residential refrigerators that run on AC power only (a dedicated inverter is installed so it can run from the batteries while in transit). For folks that have plans to dry camp and boondock a lot in their RV life, a residential refrigerator will require a much bigger battery bank and solar panel array than would otherwise be needed. We discuss that in more detail at this link in our introductory solar power article.

If our hair dryer method of defrosting an RV fridge seems unorthodox to you, believe me, we have tried many other methods. We tried opening the fridge and freezer doors and letting the fridge thaw out on its own. We tried doing that and “helping it along” by chiseling the ice off with a small plastic scraper. We tried putting a bowl of hot water in the fridge to help it warm up.

All of these methods were adequate, but they were time consuming. We’ve been using our current method with the mini travel hair dryer for a few years now and really, really like it.

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RV Storage Tip – Making Space & Getting Organized in an RV

No matter how big an RV you get, if you live in it long enough, eventually you will begin to fill it up with stuff. This has happened to us and our 36′ fifth wheel trailer. When it was new and we first moved in years ago, it was so big that half our cabinets were empty.

Since then, especially after consolidating back into our fifth wheel after living on our sailboat for nearly four years of cruising Mexico, our lives have changed a lot. We have found a new passion — photography — and all that camera gear has wound up taking over our living space.

Fifth wheel RV dinette with table and chairs

Our old dining area – no storage and seating for two.

We began storing lenses in a drawer with dish towels (soft padding) and we had four camera bags that lived on our desk and under our dining room table. Camera bodies were always strewn across the sofa, fanny packs got piled on the desk, and tripods often got stuck on top of the subwoofer under our TV. Tucking everything away for safe passage while driving was a real pain. We needed to get this stuff organized!

Mark had a brilliant idea one morning — replace our dining room chairs with big storage ottoman benches!

Storage benches in RV dinette

Our new dining area – lots of storage and seating for four.

We began researching storage benches and ottomans and found the perfect thing from Simpli Home Furnishings. They are made of a nice faux leather, and there are no decorative buttons on the top, so the plush, padded top is very comfortable for sitting on (here’s more info).

Simpli Home Furnishings rectangular storage ottoman

These storage ottomans are 36″ wide by 18″ tall and 18″ deep.

The outside dimensions are 36′ long by 18″ high by 18″ deep. The inside dimensions are 33.25″ long by 11.5″ high by 15.5″ deep.

Simpli Home Furnishings storage ottoman

Our new storage ottomans have voluminous interior space.

We bought them sight unseen from Amazon and couldn’t be happier. They come with four short legs, with three screws each, which were easy to attach.

Attach legs to Simpli Home Furnishings storage ottoman

The only assembly is attaching the four legs.

Some customers have complained that the screws are too long and coming up through the floor of the box, but the legs simply need to be oriented correctly with the three screw holes aligned with the outside edges of the ottoman.

Ottoman leg assembly

Be sure to align the screw holes with the outer edges of the ottoman.

The legs were attached in just a few minutes using our cordless drill.

Screwing legs into ottoman with cordless drill

A cordless drill makes this a quick job!

The end result is much more comfortable seating at our table and a whole bunch more storage space for our camera gear.

RV dinette with storage benches instead of chairs

Ta da!

The tricky thing about storage space in an RV is that anything located behind the coach’s rear wheels is going to bounce around a whole lot as you drive down the road. That’s why most RVs don’t have the kitchen in the rear.

Our new storage ottomans sit just slightly forward of the trailer’s axles.

Increase RV storage with ottoman bench storage in dinette

The box tops easily clear the table when they open.

Another tricky thing with storage space in an RV is that in many coaches, like ours, the shelving is very flimsy. We prefer not to put anything heavy into the wall cabinets (except in the kitchen where our cabinets are more sturdily built). But it doesn’t take long to run out of storage space down near the floor.

This new storage space is solid.

RV dinette storage bench ottoman

A few throw pillows makes these pretty darn comfortable for lounging!

We put some throw pillows on our new benches and now we’ve got not only a great place to keep our camera gear organized and a nice, new, clean look to our dining area, but we can kick back after a meal, prop our legs up on the benches and chit chat for a while. It’s fun to sit there together and get a new perspective on our little rolling home and on life!

Sitting on storage ottoman benches in RV dinette.jpg

We never used to hang out after meals on our old chairs… but this is fun!

The storage ottomans we bought are the Dover rectangular storage ottomans from Simpli Home Furnishings.
We bought them from Amazon at this link HERE.

These benches are ideal for us, but Amazon sells lots of other similar storage ottomans of different sizes and shapes too and you can find all kinds of storage benches for sale at Amazon at this link HERE).

If you find the benches are a little low, one good way to raise them up is with the plastic rug protectors made for furniture legs. We also removed the feet from our table to bring it down a smidge.

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RV Solar Panels – Flexible or Rigid? 12 or 24 volt? Mono or Poly? Yikes!

There are a lot of decisions to make when you install solar panels on an RV or boat. Some of the most basic are: what size solar panels to buy, whether to go with flexible solar panels or aluminum framed rigid panels, whether the solar cells should be monocrystalline or polycrystalline, and whether to install nominal 12 volt or 24 volt panels.

We have done several RV and marine solar panel installations, and we have used not only 12 volt and 24 volt panels of various sizes but we have also used both aluminum framed rigid solar panels and the newer semi-flexible solar panels. We have also worked with both monocrystalline and polycrystalline solar panels. This article outlines the pros and cons of the various types and sizes of solar panels and offers some things to think about when you are deciding which solar panels to buy for your RV or boat.

RV solar panel selection

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Our article RV Solar Power Made Simple explains how to determine the overall wattage for an RV solar power installation. In general, a weekend / vacation RV can get by with 200 watts or less while a full-time solar power system is best with 500 watts or more.

SOLAR PANEL SIZE and PLACEMENT

Once you decide on overall capacity for your solar panel array, the next thing to think about is solar panel placement and wiring. The panels should be a matched set of identical or nearly identical panels. If you have a lot of real estate on the RV roof, then you can get a few big panels. If you have a truck camper or your RV roof is cluttered with a lot of things on it already (hatches, vents, antennas, etc.), then you may need to go with smaller panels that can be squeezed in and around everything else.

Solar panel installation on a ffith wheel RV

Our fifth wheel trailer is powered by four 120 & 130 watt 12 volt rigid polycrystalline solar panels wired in series

WHAT VOLTAGE IS THAT SOLAR PANEL?

Solar panels are constructed internally with DC wiring, and they are sized to work on 12 or 24 volt circuits. So, they are commonly referred to as 12 or 24 volt solar panels. What’s confusing is that while the nominal voltage of a solar panel may be 12 or 24 volts, the open circuit voltage is higher. So, for a nominal 12 volt solar panel that is 100 watts, the open circuit voltage (“Voc“) will be 17 or 18 volts. Likewise, for a nominal 24 volt panel, the Voc will be 34 to 36 volts.

Also, smaller solar panels (both physically and in terms of watts) are typically nominal 12 volt panels while larger panels are typically 24 volts. Solar panels under about 150 watts in size are usually 12 volt panels. Solar panels over about 150 watts are usually 24 volt panels.

Solar panel installation on a sailboat

For nearly four years, we sailed our boat on Mexico’s coast relying on three 185 watt 24 volt
polycrystalline rigid solar panels, wired in parallel, for all our electrical needs.

Solar panels work best when they are a matched set. The electrical characteristics of all the solar panels in the array need to be very similar, preferably identical. When upgrading a solar power array this can make things complicated as you try to mix and match old small panels with new big ones.

One technique for upgrading is to wire two 12 volt solar panels in series to work on a 24 volt circuit. For instance, if you have two 100 watt 12 volt panels and you are buying a 200 watt 24 volt panel, you can wire the two 100 watt panels in series and then wire that pair in parallel with the new 200 watt solar panel.

This will work as long as the electrical characteristics of the pair of solar panels in series match the electrical characteristics of the single panel that is wired in parallel with them.

THE EFFECT OF SHADE ON SOLAR PANELS

Shade is the biggest enemy of any solar power installation. Unbelievable as it seems, a tiny bit of shade will effectively shut down a solar panel. The impact is dramatic: a few square inches of shade can drop a solar panels current production down from 8 amps to 2 amps. A few more square inches of shade can drop the current production to 0.

Before deciding on the size of the panels, it is worthwhile to take some time to study the various things that might cast shade across them once they are in place. A closed hatch may cause little shade, but when it is open on a hot day, depending on where the sun is in the sky, it might cast a big shadow across a nearby solar panel. Satellite dishes, air conditioners and even holding tank vents can cast sizable shadows as well.

We put a book in one corner of a 120 watt 12 volt panel and discovered that even though it was a small percentage of the surface area of the panel, that 8.5″ x 11″ book was enough to knock down the current production of a 120 watt solar panel by 80%. Rather than producing 7 amps, it produced a measly 1.4 amps. Egads!

Shade on one corner of solar panel

Just 8.5″ x 11″ of shade from this book reduced current production by 80%!

Similarly, shade wreaked havoc on our three185 watt 24 volt panels on our sailboat. The shade from our mast traveled across the panels as the boat swung at anchor, and the current production dropped by 1/3 and then by 2/3 as the shade first crossed one of the three panels and then straddled two of them. It did this over and over, with the current rising and falling repeatedly, as the boat slowly swung back and forth at anchor.

Effect of shade on solar panels installed on sailboat

A line of shade from the mast on our sailboat reduced our solar panel array to 65% and then 35% of its capacity as it traveled across the panels and occasionally straddled two of them.

Shade is a huge concern in the solar power industry, and there are several white papers (here’e one) about the impact of shade on commercial solar panel installations. The gist is the importance of spacing the rows of commercial solar panel arrays in such a way that one row of panels doesn’t accidentally shade the bottom inch or so of the next row behind it when the sun is low in the sky.

If it does, the second row of panels shuts down. If there are rows and rows of solar panels spaced like this, none of the panels except the ones in the first row can function until the sun rises a little higher in the sky.

Solar panels are most sensitive to shade along the longest part of the panel, so in the case of our sailboat, when the sun was over our bow, the mast would shade the panels in a strip that had a maximum impact on current production (as you can see in the above photo)!

For RVers, besides rooftop obstructions, shade comes into play primarily if you park near a building or trees. Snowbirds boondocking in the southwest deserts of Arizona and California during the wintertime have little concern with shade from trees and buildings. But summertime RV travelers who boondock in wooded areas need to be cognizant of where the shade from the trees will fall during the course of the day.

WIRING SOLAR PANELS IN PARALLEL vs. IN SERIES

One of the big decisions for a solar power installation on an RV or boat is whether to wire the solar panels in series or in parallel. There are several things to consider when making this decision.

When the solar panels are wired in series, then the developed voltage across all the panels is additive while the current remains constant from panel to panel. That is, if there were four 120 watt 12 volt panels producing 7 amps each, then the developed voltage across all the panels would be 48 volts (12 x 4) while the current would be just 7 amps.

In contrast, when the solar panels are wired in parallel, then the voltage of the panels remains constant through the circuit while the current is additive from panel to panel. For instance, for those same four panels, the developed voltage across them would be 12 volts but the current would be 28 amps (7 x 4).

The solar charge controller takes care of balancing everything out by ensuring the circuit between it and the batteries is 12 volts. In the case of the above solar panels wired in series, the solar charge controller steps down the voltage from 48 volts to 12 volts (if they are 12 volt batteries). The current then increases from 7 amps to 28 amps in the wire run going between the solar charge controller and the batteries.

In the case of the above solar panels wired in parallel, the voltage is already 12 volts, so the solar charge controller does not need to step it down for the batteries.

SHADE EFFECTS on SOLAR PANELS WIRED IN SERIES vs. WIRED IN PARALLEL

When solar panels are wired in series, if shade hits one panel and shuts it down (caused by that solar panel’s internal circuitry building up a massive amount of resistance), then the entire string of solar panels shuts down. For instance, if a tree shaded 1/3 of one solar panel in the string of four panels given above, wired in series, the current production of the entire array of four panels would be reduced to to 0 amps, even though the three other solar panels were in full sun.

In contrast, if the panels are wired in parallel, when shade knocks one panel out, the other panels are unaffected. So, even if 1/3 of one solar panel were shaded, reducing it to 0 amps of current production, the other three would be working just fine. The total current production would be 3/4 of what it could be if that one panel were in full sun (in this case, 21 amps), rather than 0 amps.

So, it would seem that the best way to wire solar panels is in parallel.

Unfortunately, it’s not that easy, and here’s why:

CURRENT and WIRE SIZE in a SOLAR PANEL INSTALLATION

The more amps of current there are flowing in a circuit, the thicker the wire needs to be to ensure that no energy is lost to heat. Unfortunately, thicker, heavier gauge wire is a pain to work with. It’s stiff and doesn’t bend around corners easily. It is hard to tighten down in the solar charge controller connections and it’s hard to crimp ring terminals onto. It is also more expensive per foot.

So, when the solar panels are wired in series, a thinner gauge wire can be used for a given distance than when they are wired in parallel.

Of course, the thickness of the wire is also dependent on the length of the wire. The longer a wire is, the more energy is lost along its length. So, if you are installing the solar panels high on an arch off the aft end of a 50′ sailboat and the batteries are located at the bottom of the hull over the keel, the wire must be a lot heavier gauge than if you are installing the panels on an RV roof directly above the battery compartment.

What is the price difference in the cable? We like to use Ancor Marine Cable because it is tinned and it is very supple (the copper is fine stranded). Here are the price differences for 25′ of 2 gauge wire as compared to 25′ of 10 gauge wire.

Ultimately, there is a dilemma: Is it better to go for thinner, cheaper wire and an easier installation, and wire the panels in series, risking that the whole array will shut down whenever a corner of one panel is shaded by a nearby tree? Or is it better to pay the extra bucks for heavier gauge wire and endure a more challenging installation but have a system that will be more tolerant of partial shade?

What to do?

SOLAR PANEL VOLTAGE and WIRE SIZE

Luckily, there is another option: higher voltage solar panels can be wired with thinner gauge wire. Remember, Watts = Current x Voltage. So, for the same number of watts in a panel, a higher voltage panel will produce a smaller amount of current.

Rather than using four 120 watt 12 volt panels wired in parallel that would produce 28 amps at 12 volts, you can use two 240 watt 24 volt panels wired in parallel that produce 14 amps at 24 volts. The net effect on the battery bank will be the same, but the bigger panels can be wired with smaller gauge wire.

As mentioned above, the wiring that is most affected by these solar panel choices is the wiring that runs from the solar panels to the solar charge controller. The wiring from the solar charge controller to the batteries is the same in either configuration, as the same amount of current will be flowing in that wire regardless of how the solar panels are wired. In the case of solar panels wired in parallel, the voltage will be stepped down in the solar charge controller. So, in our example, the solar charge controller will step down the voltage from 48 volts to 12 volts, ensuring that the circuitry between the solar charge controller and the batteries is at operating at 12 volts.

CHOOSING THE OPTIMAL WIRE GAUGE

The thickness of the wire, or wire gauge, depends entirely on how long the wire is going to be. That is, the wire gauge is determined by how far apart the solar panels and the solar charge controller and the batteries are.

Why is this? The more current that flows in a wire, the more the conductor in the wire will warm up. The more it warms up, the more energy is lost to heat. Eventually, this becomes measurable as a voltage loss between the two end points.

When wiring solar power circuits, you can choose how much voltage loss you are willing to have. Somewhere between 2.5% and 5% is typically considered okay. There are voltage loss tables that will help you decide on the proper wire gauge size for the distance you are spanning between the solar panels and the solar charge controller and between there and the batteries. Here’s a good one:

AWG Voltage Loss Table

An Example: 480 watts of solar power located 27′ from the batteries

  • Say we have four 120 watt 12 volt panels wired in series. If the distance is going to be 27′, then by looking at the third chart at the above link (the 12 volt chart) and going to the line for 8 amps flowing in the wire, it shows a wire run of up to 27′ can be done with 10 gauge wire.
  • Now, imagine putting those same panels in parallel. 32 amps will flow at 12 volts. For that same 27′ distance you’ll need 2 gauge wire.
  • Lastly, instead of using four 120 watt 12 volt panels, use two 240 watt 24 volt panels wired in parallel. For this you use the 2nd chart down (24 volt chart). There will be 16 amps flowing in the wire at 24 volts. You will be able use 8 gauge wire.

Of course, due to the nature of multi-stage battery charging and the changing position (and angle) of the sun in the sky, the solar panels will be operating at full tilt for a very short time each day. They may produce max current for 30 minutes near noon as they wrap up the Bulk Stage, however, as the Absorb stage takes over and continues in the afternoon, the solar charge controller will gradually hold the panels back so they produce far less than max current.

With less than peak current flowing in the wires, less energy will be lost to heat.

If this is confusing, see our articles:
RV and Marine Battery Charging Basics
How Solar Charge Controllers Work

So, although it may seem dire that you’re wiring is on the hairy edge size-wise, it is only that way for a little while each day. Depending on the overall size of the solar power array, the size of the battery bank, and the state of discharge when the batteries wake up in the morning, your system may not even hit the theoretical maximum current production or even come close.

MULTIPLE SOLAR CHARGE CONTROLLERS

Another method of keeping the wire size down is to install more than one big solar charge controller. For instance, you might install several smaller charge controllers for each pair of panels wired in series, or perhaps even one for each panel. Of course, this adds complexity and expense, and you will probably buy less sophisticated solar charge controllers that have fewer programming options than a single big one.

You must run more wires between the RV roof and the location in the coach where the solar charge controllers are installed (preferably next to the batteries), and so you must not only pay for additional solar charge controllers, but you must buy more wire and install it all. However, this design option does deserve mention and consideration.

TILTING THE SOLAR PANELS

Solar panels perform a whole lot better in the summer than in the winter. This is because the sun rides much higher in the sky and its rays hit the panels at a nearly perpendicular angle in the summertime. The days are also a whole lot longer. In the winter, the sun’s rays hit the panels at an angle and the sun is only out for a short while.

Solar panels on a fifth wheel RV roof

Tilting solar panels in winter can improve current production by 30%
Or…install more panels and save yourself from climbing up and down the RV ladder!

To get around this, rather than using ordinary Z-brackets to mount their solar panels on the roof, many RVers use tilting brackets. By tilting the panels towards the sun at about a 45 degree angle (technically, at the angle of your latitude), then the sun’s rays hit the panels at a nice 90 degree angle if they are oriented to face south. This can increase the overall power production by about 30% on a sunny winter day.

The only problem is that you have to climb up on the roof to tilt the panels each time you set up camp and then climb up again later to lay them flat when you are packing up before you drive away. We’ve seen many a winter snowbird driving their RV around with the solar panels still raised.

An alternative is simply to install more solar panels and to keep them lying flat all the time. This is easy for a big RV that has a huge roof but is not so easy for a little trailer with a small roof. We have not installed tilting brackets on our trailers.

MONOCRYSTALLINE vs. POLYCRYSTALLINE SOLAR CELLS

Monocrystalline solar panel

Monocrystalline
solar panel

There are lots of different kinds of solar panels on the market today. There are two primary types of solar cells used in the manufacture of solar panels: monocrystalline and polycrystalline.

Monocrystalline solar panels are more efficient and more expensive, but they are also extremely intolerant of shade. Polycrystalline panels are slightly less efficient and less expensive, but they handle partial shade just a smidge better.

The way to tell if a solar panel is monocrystalline or polycrystalline is to look at the pattern of rectangles on the panel itself.

If the circuitry between the rectangles has large silver diamond shapes, it is monocrystalline. If the pattern of rectangles is just intersecting lines, it is polycrystalline.

Polycrystalline solar panel

Polycrystalline
solar panel

Examples of popular monocrystalline solar panels are here:

Examples of popular polycrystalline solar panels are here:

RIGID ALUMINUM FRAMED SOLAR PANELS vs. SEMI-FLEXIBLE SOLAR PANELS

Flexible solar panel

Flexible solar panel

Solar panels can also be rigid or flexible.

Rigid panels are built with an aluminum frame surrounding tempered glass that covers the solar cells.

Flexible solar panels are built with the solar collecting material impregnated into a thin mylar film that is affixed to an aluminum substrate.

Flexible solar panels are not flimsy, they are simply bendable up to about 30 degrees.

 

There are a number of manufacturers selling flexible solar panels:

FLEXIBLE SOLAR PANEL ADVANTAGES

Flexible solar panels have several advantages over rigid panels. They are a little lighter than framed solar panels and you can glue them onto an RV roof using Dicor Lap Sealant, or something similar. This saves you from the complexity of drilling holes into a perfectly watertight roof and risking creating leaks. This is especially helpful with a fiberglass roof. It takes just a few minutes with a caulk gun to attach these panels to the RV roof.

Another nice feature is that on a rounded roof, like an Airstream travel trailer or Casita travel trailer, the panels can bend to follow the contour of the roof.

Installing solar panels on a motorhome roof

Mark uses Dicor Lap Sealant to affix flexible solar panels to a friend’s fiberglass roof.

One of the most important things for solar panels to work well is heat dissipation. Rigid aluminum framed solar panels stand up off the roof of the RV by about an inch, allowing air to flow underneath and for heat to dissipate. Air can’t flow underneath flexible solar panels. The aluminum substrate serves to dissipate the heat instead. This may or may not be as efficient a method of heat dissipation, and I have heard of a case where all the flexible solar panels on a sailboat had to be replaced after two years because they did not dissipate the heat sufficiently in the tropics and the panels self-destructed.

FLEXIBLE SOLAR PANEL CONSTRUCTION and INSTALLATION

Our RVing friends Dick & Katie asked us to install six 100 watt 12 volt flexible solar panels made by Eco-Worthy on the roof of their motorhome, along with all the other projects involved in an RV solar power installation. Ironically, the hardest part of the entire installation was removing the plastic protection from the aluminum substrate of each panel (it kept ripping!). We all ended up working on this together.

Flexible solar panel installation on an RV

We had a tough time getting the plastic off the back of the Eco-Worthy flexible solar panels

Removing plastic from flexible solar panel

With all of us working together, we got the job done!

Once we got up on the roof, and got past a cute warning from Winnebego, the installation was straight forward.

Warning slippery roof on RV

Hmmm…I wonder what sage advice the manual suggests for this problem?

Solar panel installation on a motorhome RV

Flexible solar panels are lighter than their rigid counterparts

The plastic protection needed to be removed from the face of the panels as well. Interestingly, at one point Mark found himself picking at the corner of the mylar that has the solar collection circuitry embedded in it and almost began to peel that whole layer off the aluminum substrate! But once he got a hold of just the most superficial layer of plastic, it came off easily.

Removing plastic from flexible solar panel

Mark removes the plastic from the face of the flexible solar panels

He used Dicor Lap Sealant to tack down the corners of the panels and then ran a bead around each side of each panel.

FLEXIBLE SOLAR PANEL DISADVANTAGES

Flexible solar panels are less efficient than rigid aluminum framed solar panels, which means you may want to get a few more total watts of solar panels than you would if you were buying framed panels. Bendable panels also can’t be installed on tilting brackets. So, again, buying more total watts may be the best solution.

Flexible solar panels are not as rugged as rigid aluminum framed solar panels built with tempered glass. Overhanging branches can scratch them. This is important for anyone that will be boondocking or dry camping a lot on public lands and in rustic public campgrounds, as it is often impossible to get in or out of a site without ducking under some low lying tree branches.

Some RVers have found that flexible solar panels installed on flat motorhome roofs tend to pool water when it rains. This can lead to debris building up and taking root and damaging the panels.

Perhaps for all these reasons, flexible solar panels are sold with a much shorter warranty than rigid solar panels. Whereas many solar panel manufacturers warranty their tempered glass aluminum framed rigid solar panels for 25 or 30 years, bendable solar panel manufacturers generally warranty their panels for 5 years or less.

This may or may not be relevant for RVers, as the fine print in almost every solar panel manufacturer’s warranty states that their solar panels are not warrantied for use on mobile vehicles.

Also, there has been a huge problem across the entire solar power industry with rigid solar panels failing prematurely in large numbers in big commercial installations (see a May 2013 NY Times article here). Apparently, just because those lovely rigid solar panels are warrantied for decades doesn’t mean they will last that long. We have already had a failure of one of our framed solar panels that was warrantied for 25 years, and we discovered the manufacturer’s warranty did not apply to RV installations.

However, as a general rule, when manufacturers warranty a product for 5 years versus 30 years, it says something about how they think their product will hold up over time.

Flexible solar panels installed on a motorhome RV roof

Nice job! (but don’t fall off that roof!)

CONCLUSION

There are many ways to go about installing solar power on an RV roof, and the solar panels that work best in one installation may not be the same as those that are best for another. Not only is every RV roof different, but every RVer’s needs are different.

If you have loads of space on a big motorhome roof or fifth wheel trailer roof, and you are setting it up for full-time use, you may be best off with three or four 200+ watt 24 volt rigid solar panels wired in parallel. If you have a little tear drop camper you use on weekends and store in the garage, a single flexible 100 watt 12 volt panel may be just the ticket for you.

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RVers Jason and Nikki Wynn have written about the condition of their flexible solar panels after a year of use HERE

Wet Cell vs. AGM Batteries & Wiring Tips for Installation on an RV or Boat!

There is a world of difference between wet cell batteries (also called flooded batteries) and AGM batteries for use in an RV or marine battery bank, because AGM batteries are totally sealed, maintenance free and keep the user from coming into contact with battery acid (electrolyte). In a nutshell, the advantages of AGM batteries over wet cell batteries are the following:

  • AGM batteries are maintenance free, which means:
    • They don’t need periodic equalizing to clean the internal plates and never need the electrolyte topped off with distilled water.
    • They do not release gasses during charging, so they don’t need special venting in the battery compartment.
    • Since gasses are not released, the terminals and battery cables do not corrode over time and don’t need to be cleaned.
  • AGM batteries discharge more slowly than wet cells, so an RV or boat can be stored for a few months without charging the batteries.
  • AGM batteries charge more quickly than flooded batteries because they can accept a higher current during the Bulk charging phase.
  • AGM batteries can be installed in any orientation, which is helpful if installation space is limited.
  • AGM batteries can’t spill battery acid if they are tipped over. This is especially important when a boat heels excessively or capsizes. (Not that you’d be too concerned about spilling electrolyte if your boat were upside down!)
RV battery upgrade from 6 volt wet cell batteries to AGM batteries

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OUR ORIGINAL BATTERY INSTALLATION

We used Trojan T-105 wet cell (flooded) batteries for nearly six years in our fifth wheel trailer, and they worked great. They were installed in our basement compartment, all lined up in a row. This was a custom installation that was done by H&K Camper Sales in Chanute, Kansas, when we purchased our trailer new from the NuWa factory in 2008.

Fifth wheel RV battery boxes in basement

Four 6 volt golf cart batteries installed in our fifth wheel basement

The original battery compartment was designed at the NuWa factory to hold two 12 volt Group 24 batteries. Group 24 batteries have the same footprint as 6 volt golf cart batteries but are about an inch shorter. We had 2″ angle iron bolted onto our fifth wheel frame so the four batteries could stand side by side in battery boxes.

Angle iron supports under an RV fifth wheel battery bank

2″ angle iron is bolted onto the fifth wheel frame
to support the batteries.

There were four venting flex hoses that ran from the battery boxes to four individual louvered vents on the front of the basement on either side of the hatch door.

RV 5th wheel basement with 6 volt battery boxes

Each battery box is vented to the outside with flex hose going to a louvered vent cover.

These batteries worked well, but because we put our RV in covered storage for 4 to 20 months at a time during the four years we cruised Mexico’s Pacific coast on our sailboat, we were not actively present to take care of the the battery charging and maintenance duties. Despite our best efforts to have someone do this while we were gone, when we moved off of our boat and back into our fifth wheel, we found our four Trojan wet cell batteries were completely dead and unrecoverable.

We replaced these batteries with four inexpensive 6 volt golf cart flooded batteries from Costco. These new batteries did not last. Within 18 months, the internal plates had sulfated badly, they took forever to charge, and they discharged extremely quickly.

6 volt wet cell batteries in fifth wheel RV basement

Upgrade time! We removed the old wet cell batteries and replaced them with AGMs.

In April, 2015, while staying in beautiful Sarasota, Florida, we replaced our wet cell batteries with four fabulous new Trojan Reliant T105-AGM batteries that Trojan had just begun manufacturing and selling. We replaced all the wiring as well.

CORROSION CAUSED BY WET CELL BATTERIES

One of the biggest problems with wet cell, or flooded, batteries is that the battery terminals and ring terminals on the battery cables get corroded easily due to the gassing that goes on when the batteries are being charged. When Mark removed the battery cables from our old batteries, he measured as much as 20 ohms of resistance from the end of each cable to its ring terminal.

Corrosion on battery cable

We measured 20 ohms of resistance between the end of the cable
and the end of the ring terminal.

Flooded batteries need to be held at 14.5 or more volts during the Absorption charging stage (depending on the battery), and at this voltage the electrolyte in the batteries begins to release gasses into the air. These gases are both explosive and corrosive, and venting them protects everything around them. However, inside the battery box these gases can corrode the battery terminals and wiring.

The best way to clean off the corrosion is with a solution of baking soda and distilled water. Put it in a disposable cup and then use a cheap paintbrush to paint it on and smooth it around the terminals and cable ends. Let it sit for a few minutes and then pour a little distilled water over it to rinse the baking soda and crud off. Dry it with paper towels.

Also, while driving down the road, the electrolyte can splash around inside the battery cells and drip out the vent holes. Dust can settle on the spilled electrolyte and can cause a minute trickle discharge across the top of the battery. So, it is important to wipe down the tops of the batteries regularly and keep them clean.

It’s a good idea to wear rubber gloves for all of this too!

6 volt wet cell RV house batteries

These batteries did not hold up well and corroded badly every few weeks.

Watch out for drops of liquid settling on your clothes when messing with the batteries. It’s nearly impossible to avoid, and Mark has holes in some of his jeans from drops of battery acid landing on his pants while he either checked the state of charge of the batteries with a hydrometer or poured distilled water into the battery terminals or cleaned the corrosion from the battery terminals and cable connections.

Battery hydrometer not used with AGM batteries

Now that we have nifty new AGM batteries, we no longer need the hydrometer!

OUR NEW RV BATTERY INSTALLTION

We chose the new Trojan Reliant T105-AGM batteries to replace our old flooded batteries because these are a completely redesigned battery from one of the top battery manufacturers, Trojan Battery. Rather than being dual purpose batteries, like othe AGM batteries on the market, the new Trojan Reliant AGM batteries are single purpose deep cycle batteries.

Trojan Reliant AGM 6 volt RV batteries

Our new Trojan Reliant T105-AGM batteries ready to go.

TRUE “DEEP CYCLE” – START BATTERIES vs. HOUSE BATTERIES

Large RV and marine batteries can be used both to start big engines and to run household appliances. However, these functions are polar opposites of each other! A start battery gives a big but short blast of current to get an engine started and then does nothing. In contrast, a house battery provides a steady stream of current to power lights and household appliances for hours on end.

Most deep cycle AGM batteries on the market today are actually dual purpose start and deep cycle batteries, largely due to the history of how batteries have developed and what they have been used for. The new-to-market (in 2015) Trojan Reliant AGM batteries were engineered from the ground up to be strictly deep cycle batteries, and the design is not compromised with start battery characteristics.

Installing Trojan 6 volt Reliant AGM battery in RV fifth wheel

Mark installs the new batteries in the old plastic battery boxes.

12 volt batteries come in many sizes: Group 24, Group 27, Group 31, 4D, 8D and more. As the battery sizes increase, they provide more and more amp-hour capacity. 6 volt batteries come in various sizes too, and the golf cart size is one of several.

The Trojan Reliant T105-AGM 6 volt golf cart style batteries (68 lbs. each) are rated to have a capacity of 217 amp-hours when two of them are wired in series to create a 12 volt battery bank. In comparison, our sailboat came with three Mastervolt 12 volt 4D AGM batteries (93 lbs. each), and we added a fourth. These batteries were rated to have a capacity of 160 amp-hours each.

The advantage of using two 6 volt golf cart batteries instead of enormous 4D or 8D 12 volt batteries is that they are smaller, lighter and easier to carry around and to put in place during the installation and easier to remove in the event of a failure.

BATTERY WIRING

We wired our four new 6 volt batteries in series and in parallel. We wired two pairs of batteries in series to create two virtual 12 volt battery banks. Then we wired those two 12 volt banks in parallel with each other.

Four 6 volt batteries wired in series and in parallel

Four 6 volt batteries: two pairs wired in series to make virtual 12 volt batteries.
Those pairs are wired in parallel with each other (red / lavender circles explained below).

Trojan Battery recommended the following wire sizes for this battery configuration:

  • 4 gauge wire between the batteries that are wired in series
  • 2 gauge wire between the pairs of 12 volt battery banks wired in parallel

This is thicker wire than many RVers and sailors typically select for their battery banks.

Because we were wiring batteries that would be physically lined up in a row, we drew out a wiring diagram to be sure we got it right.

Four 6 volt batteries in a row wired in series and in parallel

Same wiring but with the batteries lined up in a row (red and lavender circles explained below).

WIRING THE BATTERY CHARGERS and INVERTER

Because AGM batteries have a lower internal resistance, they can accept a higher bulk charging current than wet cell batteries.

Trojan Reliant AGM batteries can accept a bulk charge current of 20% of their 20 hour amp-hour rating. For the T105-AGM batteries, the 20 hour amp-hour rating is 217 amps per pair of batteries wired in series. So the max current the batteries can accept is 20% of 217 amps, or 43 amps, per pair. The wiring for each charging system should be sized for a max current flow of 43 amps.

In contrast, Trojan’s wet cell batteries can accept only 10%-13% of their 20 hour amp-hour rating. For the T105 battery, the 20 hour amp-hour rating is 220 amps per pair of batteries wired in series. So the max current the batteries can accept is 13% of 220 amps, or 28 amps.

It is important when wiring both the battery charging systems and inverter systems into the battery bank (that is, the solar charge controller, the engine alternator on boats and motorhomes, the inverter/charger or the individual DC converter and inverter), to ensure that the wiring going to those devices is connected across the entire battery bank and not to just one 12 volt battery (or 6 volt pair) in the bank.

If the charging systems are connected to the battery terminals of just one 12 volt battery, whether it’s an individual Group 24 or 4D battery or is a pair of 6 volt golf cart batteries wired in series, then the batteries in the system will not charge equally. Likewise, if only one battery of the parallel bank is wired to the DC side of the inverter, the batteries will not discharge equally.

In the above drawings, the two optimal connection points for the charging and inverter systems are shown in red and in lavender. Either pair of terminals works equally well.

We found that with individual devices for our converter, our inverter and our solar charge controller, there were a lot of ring terminals getting piled up on two of the battery terminals. So we chose the inner pair of battery terminals for the inverter and the outer pair for the converter and solar charge controller.

Since we dry camp 100% of the time and rarely use our converter except when we have to pull out our generator after days of storms or to run our air conditioning, this division means that our primary charging system spans the batteries one way while the inverter driving the AC household systems that discharge the batteries span the batteries the other way.

NOT ALL BATTERY CABLE IS CREATED EQUAL

We chose Ancor marine wire for our battery cables because it is very high quality cable. The individual strands of wire inside the casing are thin, which makes this cable very supple, despite being thick overall. It is easy to work with and to snake around tricky areas. The individual strands inside the cable are tinned as well.

This is expensive wire, but after all the wiring projects we have done on our RVs and on our sailboat, we felt it was well worth the extra cost.

We also used Ancor marine tin plated lugs made of high-grade copper with flared ends for our ring terminals (available here).

Ring terminal on battery cable

Mark slips a ring terminal onto the new battery cable.

It was critical to get a good solid connection between the ring terminals and the 2 gauge and 4 gauge wire we were using.

We don’t own a crimper of that size, but West Marine Stores often have a crimper for heavy gauge wire that customers can use, and we got an excellent crimp from a workbench mounted crimper.

Crimping ring terminal on battery cable

Crimping 2 and 4 gauge wire requires a large crimper.

With Mark hanging onto the ring terminal and me hanging onto the wire, we both pulled with all our might and we couldn’t pull the lug off the wire.

Good crimp on battery cable

A good, solid crimp.

As these projects always go, we needed to return to West Marine for crimping a few days later when we wired in our solar charge controller. We went to a closer West Marine store this time, and they had a different crimper that wasn’t quite as nice.

Using a hand crimper to crimp ring terminal onto battery cable

This wire is so thick you need a huge wire cutter!

Mark wasn’t as confident that these crimps were as good electrically as the ones made with the first crimper, even though we couldn’t pull the lugs off the wire. So he fluxed the wire and used a propane torch to flow solder into the connection. This way we had not only a solid physical connection but an excellent electrical connection as well.

Soldering ring terminal crimp on battery cable

Mark flows solder into the connector to make a superior electrical connection.

Then he slipped shrink tubing over the connection and used a heat gun to shrink it in place.

Heat gun shrink wrap over ring terminal on battery cable

Shrink tube covers the whole connection, and a heat gun tightens it up.

After our installation, we discovered that Camco makes 2 and 4 gauge battery cable and you can get them here.

Back at the RV, Mark wired the batteries up. He placed the batteries in the battery box bottoms to keep them from sliding around and put the battery box tops on as well so that if anything fell over in the basement while we were driving, it wouldn’t accidentally land on the battery terminals and short something out. We keep that area clear, but you never know when you’ll hit a huge bump and things will go flying.

Trojan Reliant AGM 6 volt batteries in fifth wheel basement

The batteries are ready for their battery box tops.

The AGM batteries do not need to be vented, so he removed all the vent flex hoses. This gave us much better access into the fifth wheel basement from the front hatch door.

Trojan Reliant AGM 6 volt batteries in fifth wheel RV battery compartment

The new batteries are installed, wired and labeled.

Without any flex hose behind the louvered vents, dust and road grime could now flow into the basement, so Mark removed the vent covers and placed a piece of solid plastic behind each one.

Replacing battery vents on fifth wheel RV

The louvered vents are open to the basement in the back and will let dust in.

RV battery vent

Mark puts a thin plastic sheet behind each louvered vent to keep dust out.

We then went on to wire in our new converter, inverter and solar charge controller (installations to be shown in future blog posts).

HOW DO THE NEW TROJAN RELIANT AGM BATTERIES WORK?

The performance of these new batteries is nothing short of outstanding. We are floored everyday by how quickly they get charged, and not one bit of corrosion has appeared anywhere.

Mark is happy not to have to check the electrolyte levels in the batteries any more or to remember to equalize them every month. The new AGM batteries are winners all around.

RV battery boxes in 5th wheel basement

Even though AGM batteries don’t have to be installed in battery boxes,
ours are because our basement is large and open and we want to protect them from falling objects!

WHY WOULD ANYONE USE FLOODED BATTERIES?

Our Trojan T-105 wet cell batteries worked just fine for us for years, and flooded are actually advantageous over AGM batteries in two significant ways:

  1. Flooded batteries are much cheaper than AGM batteries.
  2. Well maintained wet call batteries can be cycled more times than AGM batteries

Flooded batteries cost 30% to 40% less than AGM batteries. This can add up to a savings of hundreds of dollars. Depending on the value of the RV or boat, it just may not make sense to have a huge investment in batteries on board.

Also, perfectly maintained wet cell batteries can be cycled more times than AGMs. “Perfectly maintained” means staying on top of equalizing the batteries to keep the battery plates clean and also checking each cell in each battery regularly to ensure that the electrolyte is completely topped off with distilled water at all times.

Under these ideal conditions in the laboratories at Trojan Battery, the Trojan T105 flooded batteries can survive 1,200 cycles where they are discharged to 50% (12.06 volts) and then fully recharged. The Trojan Reliant T105-AGM batteries can survive only 1,000 cycles.

Of course, battery cycling in real world conditions is very different than in laboratory conditions. The degree to which RV and boat batteries are discharged and recharged day to day is far from regular (partial discharging and partial recharging are common). Also, batteries on RVs and boats that are left in storage for any period of time can be difficult to maintain and may degrade despite good intentions (like ours did).

So, the ultimate performance and value of flooded versus AGM batteries is going to vary widely from one RVer or sailor to the next. However, for us, we will not be going back to wet cell batteries any time soon!

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RV Converter, Inverter/Charger, and Alternator Battery Charging Systems

This article discusses battery charging systems that are “artificially powered” by electricity or an engine (as opposed to sun or wind power) and the methods these systems use to chargeso RV and marine batteries. It is the second post in our four part series on RV and Marine Battery charging systems.

Converter Inverter-Charger Engine Alternator Battery Charging Systems

The first article in the series, RV and Marine Battery Charging Basics, explains how batteries are charged and describes the concepts of single stage and multi-stage charging. The third and fourth articles in this series are:

You can navigate to specific parts of this article with the links below:

 

“ARTIFICIALLY POWERED” versus “NATURALLY POWERED” CHARGING SYSTEMS

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There are two basic types of multi-stage chargers for RVs and boats: those that are “artificially powered,” either by electricity, by an engine or by a generator, and those that are “naturally powered” by the sun (or wind). Note: Although this series doesn’t discuss wind charging systems, the same principles apply.

What is the difference?

Ability to Deliver the Maximum Rated Current

The biggest difference between these two types of charging systems is that artificially powered charging systems — converters, inverter/chargers and alternators — can all deliver the maximum amount of current they are rated for as soon as they are turned on. In contrast, “naturally powered” chargers may or may not be able to deliver their maximum rated current when called upon to do so.

Yamaha 2400i portable gas generator

Yamaha 2400i portable gas generator
As long as there’s gas, it’s good to go.

Solar charge controllers can deliver their maximum rated current only if they are connected to a large enough solar power array and that array is exactly perpendicular to full sunshine. Unfortunately, no matter how big the solar panel array is, these charging systems spend most of their time operating in sub-optimal conditions when the sun is low in the sky or filtered by clouds or totally absent because it is nighttime.

In addition, if a big appliance is turned on in the RV or boat while the batteries are being charged, the artificially powered charging systems can meet the challenge and provide the current that is needed (up to their rated current output and up to the limits of the power source) to keep the batteries at their target charging voltage.

Sunshine

The sun’s out — yay!
We can start charging!

However, solar charge controllers may or may not be able to meet the challenge, depending on the time of day and amount of cloud cover. In fact, if the current draw is big enough, not only will the solar charge controller fail to keep up with the sudden demand, but the net effect on the batteries may be that they are temporarily being discharged a little bit rather than charged.

Therefore, solar charge controllers have a lot of extra complexity built into their charging algorithms so they can handle the situations where, for whatever reason (lack of sun and/or too much demand from the appliances in the RV or boat) they aren’t actually charging the batteries but are just slowing down the discharge rate!

Ability to Restart the Charging Process with the Bulk Stage

Artificially powered charging systems can all be turned on or off with the flick of a switch. Most systems will test the battery voltage to see if they should jump into the Bulk stage as soon as they are turned on. This gives you a way to force the batteries into the Bulk stage and start the charging process from scratch.

Solar charge controllers operate 24/7, and they rely on an internal algorithm to determine when it is morning and time to start the Bulk charging stage. Not all solar charge controllers are designed to have an easy way for the user to put the batteries in a Bulk charging stage at any time of day other than dawn.

 

 

PROGRAMMING A BATTERY CHARGING SYSTEM

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Many artificially powered charging systems are programmable, but usually the choices are minimal. If they can be programmed at all, it is generally done with dip switches or simple buttons. In contrast, big solar charge controllers are complex enough and have so many programmable options that they often have a screen display and a menu driven interface.

Some charging systems have preset groups of voltage values, and all you can select is whether your batteries are Flooded, AGM or Gel. The charger then assigns voltage values for the charging stages based on battery type. In this case, the charging system manufacturer is guessing what voltages are appropriate for your batteries. The battery manufacturer may have different specs!

The most sophisticated (and expensive) charging systems allow you to enter any value you want for the individual charging voltages as well as the length of time to remain in the Absorb stage and other values as well.

Even if you don’t study the charging algorithm that is used by the charging systems on your RV or boat, it is worthwhile to find out what the default voltages are for the Bulk, Absorb and Float stages are on each device.

 

WHAT VALUES DO YOU PROGRAM INTO A CHARGING SYSTEM?

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There are rules of thumb for what the charging voltages should be for the various battery types, with flooded batteries requiring higher charging voltages than AGM and Gel batteries. The general consensus I found in my research was that flooded batteries preferred a Bulk/Absorb voltage in the range of 14.6 – 14.8 volts while AGM and Gel batteries prefer to be around 14.4 volts.

Because of this general consensus, I set up all the charging systems on our boat with Bulk and Absorb values around 14.4 volts so we wouldn’t fry our four Mastervolt 4D AGM batteries house batteries and our Group 27 start battery.

Needless to say, I was quite surprised when we installed our four new Trojan T-105 Reliant AGM 6 volt batteries in our trailer, that the engineers I spoke with at Trojan Battery recommended we set the Bulk and Absorb stages of our charging systems to 14.7 volts. They said the vast majority of battery failures are from chronically undercharged batteries, so they preferred that their AGM batteries be charged at this higher voltage.

I never spoke with anyone at Mastervolt back in our cruising days, and their documentation didn’t specify charging voltages. In hindsight, perhaps we should have been charging the batteries on our boat to higher Bulk and Absorb voltages. They would have charged faster, which would have been awesome, especially on solar, because our solar panel array was a little small (555 watts), and getting the batteries fully charged by day’s end was a challenge unless we turned off our DC freezer.

Lesson learned: If you can’t find your battery manufacturer’s recommended charging voltages in their documentation, give them a call!

The next sections take a look at a few artificially powered charging devices we have used and the algorithms they employ for battery charging.

 

 

CONVERTERS

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Most trailers are equipped with a converter to charge the batteries from shore power (via electric hookups or a portable gas generator). The shocking thing about these converters is that many of them are just single stage trickle chargers. (Note: if you are confused about what converters and inverters are, click here).

We had never thought much about our converter, because we use it very rarely. We don’t ever get electrical hookups, so our converter is used only when we fire up our gas generator, which happens just a few times a year. We had always assumed that the Atwood SRV 55 amp converter that came with our Hitchhiker II LS fifth wheel was a multi-stage charger. However, we discvoered a few months ago that this converter is actually a single stage trickle charger. It brings the batteries up to 13.4 volts and leaves them there indefinitely, as long as the converter has AC power supplied to it.

This is startling for two reasons.

First of all, since we boondock all the time, this means that whenever we turn on our generator to charge our batteries (after a few days of stormy weather), rather than giving the batteries a fast blast of Bulk charge followed by Absorb and Float, the batteries are immediately put into a Float stage and left there. Rather than getting a quickie does of lots of current and then trailing off to less and less current, the batteries get an anemic amount of current the whole time the generator is running.

What a waste of fuel! And who wants to listen to that noisy thing for that long! Rather than taking an hour or two to charge the batteries completely, it could take 8 hours or more. Ugh!

Secondly, single stage converters like this Atwood don’t exercise the batteries at all when they are left on shorepower via electrical hookups, and the batteries deteriorate more quickly. This is an important consideration for an RV that is plugged into shore power month after month. It is important for batteries to go through the Bulk and Absorb stages periodically.

We decided to replace our factory-installed single-stage Atwood 55 amp converter with an Iota DLS 90 converter / IQ4 smart charger a few months ago so that on the days that we use our generator we could use it for a very short time rather than running it all day.

Besides wanting a true multi-stage charger that could load the batteries up with a lot of current at the beginning of the charge cycle, we also realized our old factory installed converter was too small.

Remember that 25% rule for sizing batteries and chargers from the last post? Our converter had been sized for the two Group 24 12-volt batteries (total capacity 140 amp-hours) that had come with our RV, and we had upgraded to four Trojan T-105 Reliant AGM 6 volt batteries which gives us a total capacity of 435 amp-hours.

Our new Iota DLS-90 / IQ4 is a 90 amp converter which is much more appropriately sized to the new battery bank.

And what a world of difference there is between these two converters!

The Iota DLS 90 / IQ4 is far more sophisticated. It puts the batteries into a true Bulk charge state as soon as AC power is available (for us, that is when we turn on the generator with the shorepower cord plugged into it). Then, after cycling through Absorb to Float, it keeps the batteries in the Float stage for seven days (not applicable to us with our generator, but important for folks who get electric hookups), and then it cycles them through Bulk and Absorb again.

The multi-stage algorithm that the Iota DLS 90 / IQ4 uses is the following:

BULK: Whenver the batteries are below 12.8 volts (i.e., when first plugging into shore power or when a bunch of appliances are turned on in the RV or boat) deliver the maximum current possible (up to 90 amps DC) until the batteries reach a voltage of 14.6 volts, then switch to Absorb. If they don’t reach 14.8 volts within four hours, switch to Absorb anyways.

ABSORB: For eight hours, deliver enough current to hold the batteries at 14.2 volts.

FLOAT: For seven days, deliver enough current to hold the batteries at 13.6 volts. Then go through the Bulk and Absorb stages before resuming the Float stage.

The system is fully automatic and none of these values or times are programmable.

Note: For readers who have studied the spec sheets on the Iota DLS-90/IQ4, this outline differs slightly from what you read. I had a lengthy conversation with an engineer at Iota who explained the details of how this converter works. The documentation refers to the weekly return to Bulk and Absorb as an “Equalization” stage, but the voltages and times are actually those of the Bulk and Absorb stages. As noted in the first post in this series, equalization is generally done at 15 volts or more for less than 8 hours. In addition, the documentation describes the converter’s power supply ramping up to 14.8 volts during Bulk, but doesn’t explain that the actual trigger point that switches the batteries from Bulk to Absorb is 14.6 volts.

Using the Iota DLS 90 / IQ4 The First Time

A few weeks ago we endured several days of gray skies and rain while we were driving from Florida into southern Georgia. Our solar panels were producing very little current, and our new Trojan T-105 Reliant AGM batteries were becoming depleted. There was no sign of sun in sight.

We set up our Yamaha 2400i portable gas generator and plugged our shore power cord into it. We clamped the jaws of our trusty clamp-on ammeter around one of the battery cables and were truly astonished to see 67 amps going into the batteries. Yowza!! Within two hours the batteries had accepted roughly 100 amp-hours of charge and we turned the generator off. Our old converter would have taken about 8 hours or more to do the equivalent.

 

 

INVERTER/CHARGERS

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Many motorhomes and cruising boats are equipped with an Inverter/Charger to charge the batteries when the RV or boat is plugged into shore power. Our Hunter 44DS sailboat was equipped with a Xantrex Freedom 25 inverter/charger which was factory installed in the boat. Xantrex has since become Schneider Electric, and a comparable model being sold today is the Schneider Electric 2500 watt inverter/charger. I haven’t found an online manual for it, so I don’t know if the charging algorithm or programmability of the unit has changed.

Schneider Electric 2500 watt inverter : charger

Schneider Electric 2500 watt inverter/charger
This is the updated model of our Xantrex Freedom 25 Inverter / Charger
(ours was buried under a settee and impossible to photograph!)

Unlike many converters, most inverter/chargers are multi-stage chargers. Our Xantrex Freedom 25 had minimal programming capabilities. You could enter the battery type (Flooded, Gel or AGM), and the voltages for the charging stages were automatically assigned according to the battery type you selected. You could not enter any other values. We had AGM batteries, and the Xantrex inverter/charger assigned them defaults of:

  • Abosrb: 14.3 volts
  • Float: 13.3 volts

If you wanted different voltages, you could select the Flooded or Gel values instead simply by indicating that your batteries were Flooded or Gel, even if they weren’t.

The multi-stage charging algorithm for the Xantrex Freedom 25 inverter/charger is the following:

BULK: Deliver the maximum current possible until the Absorb voltage is reached

ABSORB: For up to 3 hours, deliver as much current as needed to keep the batteries at the Absorb voltage. If the current necessary to keep the batteries at the Absorb voltage drops below 15 amps before the 3 hours is up, stop charging and let the battery voltage settle down to the Float voltage.

FLOAT: Deliver enough current to hold the batteries at the Float voltage., and keep the batteries at the Float voltage indefinitely.

EQUALIZE: Whenever you want to equalize the batteries, you can manually put them into an Equalize charging stage. The inverter/charger will deliver enough current to bring the batteries up to 16.3 volts and will keep them at that voltage for 8 hours.

Notice how different the Xantrex inverter/charger is than the Iota DLS 90 / IQ4 Converter!. Both the voltages and lengths of time are quite different.

Even more interesting, however, is where the heck did that 15 amp thing come from for switching from Absorb to Float?

As a rule of thumb, it is thought that when the batteries need less than 2% of the amp-hour capacity of the entire battery bank in order to maintain the Absorb voltage, then they are pretty close to full charge and can be put in the trickle charge Float stage.

This 15 amp switchover is an attempt at implementing this 2% rule. However, because the 15 amp value is not modifiable, the assumption is that the battery bank is 750 amp-hours (15 is 2% of 750). That’s quite an assumption! More sophisticated charge controllers allow you to program the current at which you want the system to switch from Absorb to Float.

Our boat’s battery bank was 710 amp-hours, so a more accurate number would have been 2% of 710, or 14 amps. 15 amps versus 14 amps — big deal, right? It’s true, for an inverter that is going to be running 24/7 when you are plugged into shore power, that slight difference is not significant.

But if you are using the inverter/charger with a generator (to supplement solar power during stormy days), you might want to stay in the Absorb stage for the full 3 hours rather than dropping into Float as soon as the current dips below 15 amps!

Also, as I’ll show in the next post in this series, 15 amps was still much too high a current — in our case — to switch from Absorb to Float when we charged our boat’s battery bank with our solar charge controller. We wanted the switch-over current from Absorb to Float to be only 5 amps.

 

 

ENGINE ALTERNATOR

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Cruising sailboats and motorhomes are equipped with an engine alternator that charges the batteries. Our sailboat had a 100 amp Balmar alternator with an ARS-4 Smart Charger which was a multi-stage voltage regulator.

Balmar 100 amp engine alternator

Balmar 100 amp diesel engine alternator

The multi-stage charging algorithm the ARS-4 Smart Charger uses is the following:

BULK: For 36 minutes deliver maximum current until the batteries reach the Bulk voltage. If the Bulk voltage is not attained in 36 minutes, then continue delivering that same current for 6 more minutes. If, again, the Bulk voltage has not been reached, continue for 6 more minutes and check again. Repeat this cycle until the Bulk voltage is reached.

ABSORB: For two hours, deliver enough current to keep the batteries at the Absorb voltage. If after two hours the batteries are not at the Absorb voltage (due to large current draws from systems on the boat or RV), check every six minutes until the Absorb voltage is achieved.

FLOAT: For six hours, deliver enough current to keep the batteries at the Float voltage. After six hours, increase the current being delivered to the batteries to bring them up to the Abosrb voltage and keep them at that voltage 36 minutes. Then return to Float for six more hours. Repeat this cycle indefinitely.

EQUALIZE: The equalizing stage is started manually and you can choose the voltage and time limit.

This charging system is quite programmable. The user can enter the length of time of each stage, and all the voltages can be programmed to any value as well. The factory default voltages are:

  • Bulk = 14.1 volts
  • Absorb = 13.9 volts
  • Float = 13.4 volts

Notice that with this particular engine alternator the batteries are not left in the Float stage indefinitely. Instead, they are put into Float for six hours and then in Absorb for 36 minutes, cycling between those two stages indefinitely.

How long is “indefinitely” when it comes to running a boat’s engine, anyway? Well, we had lots of 24 to 55 hour passages on our cruise where the engine ran nonstop. The alternator cycled between Absorb and Float quite a bit during those passages.

 

 

SIZING AN ENGINE ALTERNATOR TO A BATTERY BANK

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One really important aspect of using an alternator to charge a large battery bank, especially if the engine will be running when huge loads are put on the batteries (like the anchor windlass or power winches), is the 25% rule of thumb I mentioned in the first post of this series: the rated output current of a charger should be roughly 25% of the capacity of the battery bank.

Most cruising boats have very large battery banks. Ours was 710 amp-hours, and we knew lots of cruisers with 600 amp-hour banks all they way up to 1,000 amp-hour banks. For us, 25% of our 710 amp-hour battery bank calculates to 177, so our alternator needed to be a 180 amp alternator to be sized correctly.

The problem is that most alternators over 100 amps require a double pulley system on the engine. That’s complicated, and very few cruisers choose to go that route. Instead, they tend to limp along with undersized alternators.

And what is the most common system failure we saw sailors experiencing on their cruising boats? Alternators!

Not only are most cruising boat alternators undersized, most alternators are called upon to power the anchor windlass, lifting a 60 or 70 lb. anchor along with 100 to 300 feet of stainless steel chain from a depth of 20 or 30 feet. Frequently, it does this in pre-dawn hours of the morning, after the sailors have spent an evening with lights and laptops running and maybe watching a movie. The boat’s batteries are depleted and the solar panels are still asleep and aren’t helping out. It’s like asking a weak and starving person to move furniture.

 

FINAL NOTES

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The manufacturers of converters, inverter/chargers and diesel engine alternators each approach the methodology of multi-stage charging in unique ways, and the charging systems described on this page are just a few examples from our own personal experience.

If you have the time and the inclination, read the user manuals of the charging systems on your RV or boat, find out what your battery manufacturer gives for recommended settings, and set your charging systems up accordingly.

To continue to the next article in this series, click here:

Solar Charge Controllers – Optimizing Battery Charging from the Sun

4-Part Series on RV and Marine Battery Charging Systems:

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RV Electrical System Overhaul – New Batteries, Inverter & Converter!

April 2015 – For the past ten days we’ve been doing a total overhaul on our RV’s electrical power systems, and we’re really excited about the upgrades. Having installed several RV and boat solar and battery systems to date, both for ourselves and for friends, we’ve gone all out this time, researching, studying, and talking with the engineers at different companies to figure out which components will suit our needs best. Our upgrades include:

  • Trojan Reliant AGM batteries
  • Exeltech 2000 watt pure sine wave inverter
  • Iota 90 amp converter / multistage charger
Trojan Reliant AGM 6 volt battery

We’re getting new Trojan Reliant T105-AGM batteries!

NEW AGM BATTERIES

Since we live on solar and battery power in our RV 100% of the time, having a robust power plant on board makes all the difference. Back in 2008 when we first got our fifth wheel trailer, we asked the RV dealership to install four Trojan T-105 6 volt wet cell batteries for us. These were terrific and served us very well for quite a few years.

However, because we had to leave the trailer in storage for stretches of 12 to 20 months at a time when we cruised our sailboat in Mexico, they deteriorated because no one was there to do the routine maintenance they require.

Wet cell batteries are inexpensive, which is why we chose them at the outset of our RVing life. However, once we started living with higher quality AGM batteries on our sailboat, we found AGM batteries have many advantages over wet cells (our boat had four Mastervolt 4D AGM house batteries and one Mastervolt Group 27 AGM start battery). So we decided to upgrade our RV battery bank to AGM.

Much to our surprise, we managed to time this upgrade really well, because Trojan Battery has revamped, redesigned and re-engineered their AGM battery line completely, and their new Reliant AGM batteries have just hit the market in the last month.

Trojan Reliant AGM 6 volt battery

Our new batteries go into the fifth wheel basement.

The batteries we are installing are their new 6 volt AGM battery called the Trojan Reliant T105-AGM.

Trojan Battery has been at the forefront of battery engineering and technology for decades, and this new AGM version of their ultra popular T-105 6 volt wet cell batteries is a true deep cycle AGM battery, designed to deliver steady power and withstand deep discharging of 50% of the battery’s capacity day after day after day (we plan to discharge them 25%-30% or less each day).

Most AGM batteries are actually dual purpose, designed not only to provide long-term power and deep discharging, but also to pack a high cranking power punch that can get an engine started without discharging the battery much at all. Our boat’s AGM batteries were all dual purpose marine batteries, despite their enormous size.

Obviously, a battery designed specifically for repeated deep discharging is going to be superior as a house battery to one that is designed to be both a deep cycle house battery and a start battery. So these new Reliant AGM batteries should work really well in an RV (or boat!).

The list of advantages of AGM batteries over wet cells is considerable:

  • Maintenance free – no equalizing and no adding distilled water (great if the RV gets stored for months on end)
  • Discharge just 3% per month when they aren’t being used (also important for longer term RV storage)
  • Charge more quickly than wet cell batteries
  • No gasses released during charging, so no special venting is needed in the RV battery compartment
  • Can be installed on their sides or ends since there is no liquid that can spill out

Mark has been very busy revamping our fifth wheel basement battery compartment, and he is taking this opportunity to rewire it entirely, applying all the things we’ve learned in 8 years of living off the grid!

NEW and BIGGER INVERTER

At the same time as our battery upgrade, we also decided to upgrade our inverter. We have loved our Exeltech XP1100 Pure Sine Wave Inverter since we installed it in 2008.

Exeltech makes all the inverters used by NASA, and they supplied all the inverters to both the American and Russian sides of the International Space Station (the two sides run on different voltages and currents, so they need different inverters!).

Exeltech XP 1100 Inverter

Our old Exeltech XP 1100 pure sine wave inverter is getting replaced with the 2000 watt version

Exeltech XPX 2000 watt pure sine wave inverter

Our new Exeltech XPX 2000 watt pure sine wave inverter

The quality of the electrical signal produced by Exeltech inverters is so pure that they are used by field medical units to run sensitive medical equipment. One nice thing about living on inverter power exclusively is that we never have to contend with flakey RV park electricity, and we know our Exeltech inverter is giving us a great signal whenever we turn it on.

Our old Exeltech XP1100 inverter was too small, however. We have a 900 watt microwave, and 1100 watts of inverter power was shaving it just a little too close. A mishap last year made us realize we needed to go bigger. So we are installing an Exeltech XPX 2000 Pure Sine Wave Inverter that will give us 2000 watts of power.

NEW MULTI-STAGE CHARGING CONVERTER

Solar panels charge our batteries almost all the time, but once in a while we get stuck in overcast and stormy conditions for a while. After about 4 days of grey skies, we turn to our trusty Yamaha 2400i portable gas generator to bring our batteries back to full charge. When we run the generator, we plug the generator into our shore power input connector on the side of our trailer so the converter in the fifth wheel basement charges the batteries.

Our fifth wheel trailer came from the factory with an Atwood 32 amp converter which is a single stage battery charger. This is typical of converters installed in RVs. Rather than going through three stages of charging, these simple converters give the batteries a mere trickle charge at a low charging voltage.

RV manufacturers save on costs by installing basic single stage converters rather than robust multistage charging converters, and since most RVs are plugged into shore power all the time, it doesn’t matter if it takes 48 or 72 hours to charge the batteries completely.

Iota DLS-90 Converter

The Iota DLS-90 / IQ4 Converter does true multi-stage battery charging

Sperry Gardner Bender DSA 540A Clamp-On Volt - Amp Meter

Sperry stands behind their gear!

However, the only time our converter is charging our batteries is when we run our generator, and with that thing making noise and burning fuel, we want the batteries to be charged as quickly and efficiently as possible. We don’t want to trickle charge our batteries from the generator!

We are replacing our old converter with an Iota DLS-90 / IQ4 Converter which not only provides three stages of battery charging but will also put the batteries into a true bulk charge state when we first turn on the generator.

So, with all this wiring going on, we’ve been giving our trusty Sperry Clamp-on Amp/Volt Meter a good workout lately. And we’ve had a surprising experience with that little piece of gear.

We bought it back in 2010 when we were wiring up the solar power on our sailboat. But it died 10 days ago, right as we were starting our new RV power upgrade project. Of course, the warranty ran out a long time ago, but we called the company to see if there was anything they could do. We were shocked when they sent us out a replacement unit at no charge!

It is so rare these days for a company to stand behind its products like that, especially something small and inexpensive like a volt meter. Wow!

We’ll be posting much more detailed info about our electrical system upgrade once we’ve finished it all, so stay tuned!

For now, we’re extremely grateful to our good friend “Mr. G” who invited us to shoehorn our rig into his driveway in Sarasota, Florida, and make use of his workbench, tools and fabricating expertise as we tackle this exciting project.

Fifth wheel RV between houses in Sarasota Florida

A great spot to do a little upgrade work on our rolling home!

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RV Heater – How to Install a Vent-Free Propane Heater in Your RV

Installing a vent-free propane heater is one of the best upgrades you can do for your RV if you plan to be spending a lot of time in chilly places. This page reviews how ventless propane heaters operate in comparison to traditional RV furnaces, it discusses the different technologies used in the design of various types of vent-free gas heaters on the market today — including catalytic heaters, ceramic brick and plaque heaters, and blue flame heaters — and it presents a step-by-step guide for installing a vent-free propane heater in your RV or camper.

You can jump to the various sections of this page here:

 

This post was first written in January, 2009, but was completely overhauled and rewritten in October, 2014.

INTRODUCTION

 

Warming my hands over a vent-free blue flame propane heater in my 5th wheel camper RV

Happiness is… a vent-free propane heater!

We froze in our trailer during our first winter in Arizona. Morning temperatures in the kitchen were often 40+ degrees F, and although daytime temps could get as high as 70, as soon as evening came, the temps in our trailer dropped into the the 50’s.

Brrr! It’s hard to sit around in the evening in those kinds of temperatures. All modern motorhomes and campers (ours included) come equipped with a propane furnace. However, these loud, inefficient beasts use a lot of electricity, and can drain the batteries in one night.

During that first winter (2007-08) in our 27′ Fleetwood Travel Trailer, we discovered that the more experienced winter desert boondockers (both snowbird RVers and those living the full-time RV lifestyle) installed vent-free propane heaters in their rigs. These are wonderful little appliances that use far less propane than a furnace and no electricity at all. When we upgraded to our 36′ Hitchhiker 34.5 RLTG fifth wheel in May, 2008, we decided we would install one. All summer long we thought about the project, but never found ourselves in a town where there was a good selection of heaters to look at or anyone knowledgeable about installing them in RVs. So we dawdled.

As the nights got colder in late November, 2008, and we relied more and more on our trailer’s electricity-eating furnace, we found ourselves in the warm company of our good friends Bob and Donna Lea Jensen and their vent-free, electricity-free propane heater. Bob has installed quite a few of these little devils over the years, and he gave us some hints and loaned us two critical tools for the project: a pipe cutter and a flaring tool. We learned a lot through this process, and I thought it might be helpful, along with our other RV tips and tricks pages to include some notes here about our project.

There are several types of vent-free heaters on the market, and each has its pros and cons. In the end, we opted to buy a 20,000 BTU thermostatically controlled blue flame heater made by Vanguard. The night before the installation we laughed as we bundled ourselves into our recliners wearing multiple layers, buried under blankets for the last time. Mark’s face peaked out from under his hood as he read. The night after the installation, in shorts and t-shirt, I had to poke my nose out the window to get some cool air. In our excitement, we had inadvertently heated the bedroom to 85 degrees.

We have used and loved this heater year-round ever since, running it near sea-level in the southern states in the winter months and using in the cool mountains during the summer months!

 

COMPARISON OF RV FURNACES AND VENT-FREE HEATERS

RV PROPANE FURNACES

Propane uses oxygen as it burns and gives off moisture as a by-product. Therefore it has the potential to use up all the oxygen in an enclosed space and kill any living, breathing occupants while creating a layer of condensation on the insides of windows. Yikes! To accommodate these unpleasant aspects of propane heating, conventional RV propane furnaces use a large blower system to bring in outside, oxygen-rich air. In turn, they vent the moist, oxygen-depleted air from inside the rig to the outside. Circulating the air this way keeps the oxygen level in the air fairly constant and significantly reduces the build-up of condensation on the insides of the windows, as the moisture gets blown outside along with the exhausted air.

Atwood RV furnace
However, by blowing all this warm air outside, the furnace is effectively heating the outdoors. If you stand outside an RV next to the furnace vent on a really cold day, you can warm your hands and body quite nicely. Also, this blower requires electricity to run. RV furnaces are DC, so they do not require an inverter or generator in order to operate. However, the amount of power they use is astronomical (our 40,000 BTU furnace uses 11 amps DC). If you are boondocking, or dry camping in the desert as many winter Snowbird RVers do, you are then faced with a choice of either keeping the RV unacceptably cold, or using a generator to keep the batteries charged (even our big solar power installation on the Hitchhiker 5th wheel was not enough to keep up with the furnace blower during the winter).

Besides heating the outside air and running the batteries down, a major disadvantage of a standard RV propane furnaces is that the blower is really loud. There is nothing like being deeply absorbed in a really great movie and listening to some very profound dialog being exchanged in whispers, and having the furnace suddenly roar to life and drown out everything being said. Our furnace blower often woke us up out of a sound sleep too.

VENT-FREE PROPANE HEATERS

In contrast, vent-free propane heaters are silent and provide heat without using any battery power. This is because they rely on you to give them fresh air: you have to crack open a window while they run. All US-made vent-free heaters are built with an internal oxygen sensor that shuts off the heater if the oxygen level in the room becomes too depleted. In addition, most RVs come equipped with an LP gas detector that will sound alarms if the oxygen in the air drops too low or if an LP gas leak is detected and you can install a combo LP/CO detector as well to detect both LP gas and carbon monoxide. You may also need (or choose) to run a small fan to circulate the air. This will use some battery power, but you can decide how much or how little to use the fan.

Living without heat in an RV

Brrr… This was what life was like before we installed our vent-free propane heater!

So, in essence, when using a vent-free heater, you must find a happy balance between several variables. Determine which kind of heater will best suit your needs (see descriptions below), figure out where to place it in the RV, which window(s) to crack open, and how often to run a fan (if at all), and if so, which kind of fan to use (a little DC fan, like one used in a computer, a large AC ceiling fan that will require an inverter or generator to run, or an optional blower fan that can be purchased with the heater).

Heat rises, so in 5th wheel campers the heat tends to gather in the bedroom. Simply close the door to the bedroom, or crack it slightly open to control the movement of the warm air into that space. Likewise, if you use a ceiling fan, you can experiment with running it forward or backward, either to draw air up and move it out along the ceiling or to push the warm air down towards the floor.

Propane has a fixed capacity for providing heat. One gallon of propane contains 92,000 BTUs of potential heat, which means a 40,000 BTU RV furnace running full blast will burn through nearly a gallon of propane every two hours or so. During the coldest periods, it is a real pain in the neck to keep having to refill the propane tanks as you fly through propane trying to heat your rig.

Our Lynx travel trailer came with a 30,000 BTU furnace, and our Hitchhiker 5th wheel came with a 40,000 BTU furnace, both installed at the factory. These were sized appropriately for the square footage of each camper. However, we have found we can easily heat our big fifth wheel to higher temperatures in less time using our 20,000 BTU vent-free propane heater instead of the factory-installed 40k BTU RV furnace. So, a smaller vent-free heater that burns less propane per hour can effectively heat a given space more quickly than a traditional RV furnace that is twice its size.

Because of the inefficiency of RV furnaces in terms of propane use and battery power consumption, when we use the RV furnace alone for heat in 30+ degree F overnight temps and 40+ degree daytime temps, we find we have to keep our trailer at 50 degrees while sleeping at night and at just 60+ degrees during the day. Cold as that sounds, this uses up almost a gallon of propane a day and we can barely keep the batteries topped off using our 490 watts of solar panels alone. Worst of all, living like this is really uncomfortable.

Using our vent-free blue flame heater in the same conditions and burning the same one gallon of propane per day in those conditions, we can easily keep the 5th wheel at 76 degrees all day long. And we use almost no electricity.

To clarify, we have two 30 lb (7 gallon) propane tanks, and when outside highs are in the 50’s and lows are in the 20’s, we go through a tank of propane each week. When outside highs drop below freezing 24/7, we can go through a tank in 3 days.

 

WHICH IS THE BEST TYPE OF VENT-FREE HEATER?

 

When choosing a vent-free propane heater, there are a lot of products on the market. Catalytic and ceramic heaters produce infrared radiant heat which heats objects situated nearby much the same way the sun does. They create a warm, baking sensation on your skin, but if you move away (like moving into the shade outdoors), that sensation goes away. The air in the room warms up over time as the objects in the room warm up.

In contrast, blue flame heaters heat the air, rather than the objects in the room, providing a more even, uniform warmth. Gradually, the objects in the room heat up as the overall temperature of the air in the room rises.

All of these heaters come in different sizes, ranging from 5,000 to 30,000 BTUs, which are good for heating 100 square feet up to 1,000 square feet. Small ones can be hung on the wall, out of the way, while big ones that appear modest-sized in the show room suddenly become monster heat sources that dominate the floor space when you get them home to your RV.

 

CATALYTIC INFRARED RADIANT HEATERS

Olympian Wave-8 Catalytic infrared radiant heater for use in an RV
Catalytic heaters were the original vent-free heaters. The major brand is the Olympian Wave, manufactured by Camco, and their primary models are the Wave-3, Wave-6 and Wave-8 heaters. These provide 3,000, 6,000 and 8,000 BTUs of heat respectively.

Catalytic heaters provide infrared radiant heat by way of a large pad on the surface of the heater. A chemical reaction in the pad causes heat to radiate off the entire pad. If you stand in front of a catalytic heater, your skin will feel a nice baking warmth on it. The closer you sit, the more you will bake. This is a great feeling when you are chilled.

These heaters have been in use for years, and have an enthusiastic following. They are also quite expensive ($300-$430), often as much as double the cost per BTU as the other types of vent-free heaters. They do not have thermostats, just a “high” setting and a “low” setting, so you must manually turn them on and off or to high or low to regulate the temperature in the RV.

If the pad on these heaters becomes dirty, it is possible to replace it for about $100. A friend of ours tried to clean his by vacuuming it, and inadvertently ended up destroying the pad. Because the pads had changed slightly since he bought his unit five years earlier, he could not replace the pad and had to replace the entire heater instead.

You will need a brass elbow fitting from Camco for the installation. You may also want leg stands so the heater can stand on its own two feet and a dust cover to protect the catalytic pads when it is not in use.

 

CERAMIC (BRICK or PLAQUE) INFRARED RADIANT HEATERS

Mr. Heater Ceramic infrared radiant heater for use in an RV
Ceramic infrared heaters are a slightly newer technology that has been warming RVs for quite a few years. The most popular brand on the market is Mr. Heater. Other brands include Kozy World, Empire and ProCom. These are generally offered in one, two, three and five brick configurations providing 5,000, 10,000, 15,000/20,000 and 25,000/30,000 BTUs of heat.

Ceramic heaters provide the same infrared radiant heat as catalytic heaters. Across the front of the heater there are small ceramic “bricks” or “plaques” that heat up to a glowing orange/red color. Like a catalytic heater, standing in front of a brick (or plaque) ceramic heater will toast your toes to your thighs on the front of your legs. The heat from the bricks interacts with your skin and you will feel a wonderful tingly warmth.

These are extremely popular units and can be quite inexpensive ($130-$350). Most can be purchased with or without a thermostat. One big disadvantage is that the area directly in front of the bricks gets hot enough to burn things. Any flammable items that come too close to the bricks could catch on fire. If a cat or dog wanders past and flicks its tail against the bricks, it might get singed. If a toddler sticks its fingers in there, a trip to the hospital might ensue.

 

BLUE FLAME HEATERS

Mr. Heater Blue Flame vent-free propane heater for use in an RV
Blue flame heaters are the newest technology and provide a different kind of heat than the catalytic and ceramic heaters. Rather than radiating heat, blue flame heaters operate via convection (the principal that heat rises), drawing cool air in through vents at the bottom of the heater and emitting warm air out the vents in the top. This is a heating method that is much like central heating in a house. Once the air temperature has risen sufficiently, the objects warm up as well. If you keep your RV at a warm temperature all the time (especially at night), the objects in the room will never get cold.

Blue flame heaters draw cool air in from floor level through a row of vents at the bottom, heat it up, and emit the warm air out of vents at the top, relying on convection (the fact that heat rises) to move this air instead of using a blower. You can warm your hands and body by standing in front of one, but it is more of a warming sensation than a baking one. The area in front of the blue flame is covered by fireproof glass (it’s actually a ceramic material) and it is not burning hot. So, there is no risk of items immediately in front of the heater catching fire. Blue flame heaters are a good idea for people with pets or children.

The most popular brand is Mr. Heater. A few others include Empire Heating Systems and ProCom, the same makers of the ceramic brick heaters. These manufacturers produce both blue flame and brick heaters in the same chassis, so other than the appearance of the bricks or the flame, the unit itself has the same look whether it is the brick or blue flame version. The typical BTU range on these heaters is 5,000, 10,000, 20,000 and 30,000.

Blue flame heaters are as popular as the brick ceramic heaters, and are in the same price range of about $130-$350. They can also be purchased with or without a thermostat.

BLUE FLAME FIREPLACES !!

Pleasant Hearth Vent-Free Propane Fireplace 35 inch

.

There are some wonderful blue flame heaters that are designed to look like fireplaces, complete with logs, trim and beautiful wooden mantels. Manufacturers include Pleasant Hearth and ProCom.

These cost about $200-$300 more than the regular blue flame heaters, but what a beautiful addition to your RV. You can sit and watch the yellow flames dancing around the logs and warm your bones at the same time. I saw one of these units in an old travel trailer and was enchanted. The owner had built his own mantel out of an old coffee table, and it was lovely. I wanted one of those units so badly!!

The only place for a unit like that in our rig was along the backside of the “L” in the kitchen counter, which is just a few inches from the wall of the entertainment slide-out when it comes in. If we had the carpentry skills, we probably could have slipped a fireplace in there, recessed under the counter.

The only downside would have been that it might have gotten a little hot under the counter, and we would have had to be extra careful that the heater was fully cooled whenever we brought the slide-out in, or we would have cooked the gelcoat on the outer wall of the slide. Also, as it turned out, that particular location for the heater would not have provided the same warmth when we sat in our recliners as the heater does in its current spot in the kitchen in front of the oven (even though it would have been closer). It’s just the way the air flow circulates in our particular trailer.

PORTABLE HEATERS

Mr Buddy Portable vent-free propane heater

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If you don’t want to hassle with installing a dedicated gas line for a vent-free propane heater in your RV, you can opt to get a portable unit instead. The portable ventless heaters are all infrared radiant heaters with bricks (plaques) that have air intake vents in the bottom for convection as well. They have built-in blowers that run on a 6 volt a/c adapter (sold separately) or on 4D batteries. They are very popular.

They are manufactured by Mr. Heater (with the brand name “Big Buddy”), and they come in sizes from 4,000 to 18,000 BTU. They run on the small Coleman style portable propane canisters but can also be connected to a larger BBQ style propane tank.

If you plan to run the heater from a large propane tank instead of the little propane canisters, Mr. Heater sells a companion flexible gas hose with a regulator and quick release connector on it for just that purpose. Mr. Heater make nice carrying cases for these heaters as well.

 

OPTIONAL EQUIPMENT for VENT-FREE PROPANE HEATERS

Thermostat

Usually this option is just $30-$50, and it is well worth the cost if you plan to be in your RV for extended periods of time. A manually controlled heater will have several heat settings (usually three), but you will need to monitor the heat in the room and adjust the settings as you get warmer or cooler. A thermostatically controlled heater will cycle on and off as its sensor detects changes in temperature. Ours typically cycles on and off in 5-10 minute increments, keeping the temperature within 2 degrees.

On our unit, the thermostat has a simple analog dial that can spin from “1” to “5.” These are arbitrary numbers rather than fixed fahrenheit degree markers. However, once you figure out how “1 1/4” or “2 1/2” relates to temperature, you can keep the temperature in the room tightly controlled by turning the dial to the setting you want. This is especially nice if you plan to keep the heater on all night, as the temperature in the RV will remain constant while the outside temperature drops.

Feet

Most units are designed to be hung on a wall, however most also have an optional stand so they can be placed on the floor. Most smaller units include the feet as an option (about $25) while most larger units come with the feet at no extra charge. The great advantage to hanging a unit on the wall is that it is always there, ready for use. If you use your RV during all four seasons, it is nice to know that if you suddenly find yourself in a chilly spot, you can simply flip the switch and have your heater working for you, rather than digging it out of the back of the closet (a lesson we learned after the fact!).

The advantage of having the unit standing on its own two feet is that you can move it around the rig. This is especially true if you don’t use a fan of some kind to move the warm air around the rig. If you go this route, make sure you have plenty of flexible gas hose so you get maximum range for placing the heater in different spots in the rig.

Blower

Most ventless gas heaters can be purchased with an optional blower. As soon as you start blowing the air around the RV, you are signing up to use the batteries to keep the rig warm, something the vent-free solution was aiming to avoid. However, the power consumption should be less overall than a furnace. Some blowers are thermostatically controlled, allowing them to cycle on and off as needed. This is efficient, as the blower and batteries won’t be in use all the time the heater is on. Rather than a built-in blower, many people opt to install a small DC fan which uses very little power. If your rig has a ceiling fan, that can also be an option, although it will require the inverter or generator to be turned on. In our case, our inverter is turned on from the moment we wake up until we go to bed, so running the ceiling fan when the heater is on during the day is no big deal.

 

HEATER PLACEMENT

When we installed our ventless propane heater, we tried placing it in several locations. We also tried turning our ceiling fan both on and off and running the fan both forwards and backwards (blowing towards the floor and towards the ceiling) before we settled on a final arrangement.

Kozy World Vent-Free Propane Heater connected to flexible gas hose

This ceramic heater has a flexible gas hose that allows it
to be moved around the RV.

We found that the best setup was to place the heater directly below our ceiling fan (in front of the oven at the base of the stairs in the kitchen) and to set the fan to blow towards the ceiling, drawing the warm air up and distributing it outwards throughout the RV. It was astonishing to find what a difference it made as we moved the heater to various places in the trailer and tried each placement with or without the ceiling fan, and blowing up versus blowing down.

Our RV is a “rear lounge” fifth wheel
, and we found that the area around the recliners was a significant cold air pocket. Doesn’t it figure! That’s where we like to be on cold evenings!! There are large windows surrounding the recliners, which make that area cold, while the warm air in the rig congregates high up on the ceiling just in front of the stairs leading to the bedroom (that is, if the bedroom door is closed. Otherwise the warm air settles in the bedroom itself).

We assumed that facing the heater towards the recliners just 5 feet in front of them would warm up this cold pocket. Wrong! No matter how high we set the thermostat, and no matter what we did with the ceiling fan (which is located 10 feet away right in front of the stairs leading to the bedroom), the recliners were still cold.

When we moved the heater to the base of the stairs leading to the bedroom, and turned the ceiling fan on “high” and set it to blow towards the ceiling, we could immediately feel the warm air encircling us as we sat in the recliners. Who woulda thunk??!!

Heater Sizes and Capacities

Most manufacturers state the square footage their various heaters are designed to heat. We decided that we’d rather buy a slightly larger unit (that is, one rated for a larger space than the interior of our fifth wheel), and simply keep the heater on a lower setting than to find ourselves unable to heat the buggy adequately. Our rig is 360 square feet, which put us somewhere between 10,000 and 20,000 BTUs. We ended up buying a 20,000 BTU heater, and we typically keep it set to 50% of maximum during the evenings/mornings and 25% of maximum at night when temps outside are in the 20’s and 30’s. If we had purchased a 10,000 BTU unit instead, I think it would have been cranking at max volume most of the time during the mornings and evenings and on stormy days. As a rough guide:

Vent-free heater BTU ratings and square footage
6,000 Up to 200 sf
10,000 Up to 300 sf
20,000 Up to 700 sf
30,000 Up to 1,000 sf

There are legal ratings for the sizes of vent-free heaters and the rooms they can be operated in. Less than 6,000 BTUs is okay for a bathroom, and less than 10,000 BTUs is okay for a bedroom. These are the ratings that are being referenced when you see a sticker on a larger unit saying “not designed to be used in a bedroom.” The idea is that a large unit operated at max volume in too small a space will use up too much oxygen in the room too quickly. Of course, such a scenario would have the occupants of the room running out the door because it would be way too hot for comfort.

 

SAFETY OF VENTLESS PROPANE HEATERS

Some people may worry that these kinds of ventless propane heaters aren’t safe, fearing that it might blow up the RV or suffocate them. These heaters are extraordinarily well regulated by various governing bodies, and designers have to meet stringent guidelines and submit their heaters to a battery of very challenging tests before they can be brought to market. Vent Free is the industry organization for all the vent-free gas heater manufacturers. Their website spells out all the testing, guidelines, state by state requirements, laws and safety record for these heaters. Through September 1, 2005, they claim that there had not been a documented death due to a vent-free propane heater (see that claim here). Visit their website at ventfree.org.

In addition, at the factory, RV manufacturers install a LP Gas Detector Alarm system (various brands are used) to detect LP gas leaks in the RV and alert anyone inside. These are installed because many RVs come equipped with propane-based appliances, including things like the stove, oven, hot water heater, refrigerator and RV furnace. All RV owners should be aware of where their LP gas detector is located. It is usually installed near the floor, as LP is a heavy gas that settles down low. Propane is found in highest concentrations near the floor.

Some RVers run their vent-free propane heater overnight as they sleep. We don’t do that. If the overnight low temps will be well below freezing (i.e., 25 degrees F or below), we run our RV furnace, set to 50 degrees, all night long to keep the plumbing from freezing, because the furnace is ducted throughout the basement.

 

OPERATION AT HIGH ELEVATION

Most of these heaters are sold with an official limit for operating altitude. The problem at higher altitudes is that there is not enough oxygen for the propane to burn properly. Some units are rated for use up to only 3,500 feet, while other manufacturers have a stated limit of as much as 5,000 feet.

Our blue flame vent-free propane heater is rated for use up to 4,500 feet, but we have used it extensively at altitudes up to 8,500 feet and have used three times for two week periods at 10,000 feet.

The key to operation at altitude is the Oxygen Detection Safety-pilot (ODS) sensor which has been standard equipment on all US-made vent-free heaters since the 1980’s. This sensor shuts off the gas to the heater when it detects the oxygen level has dropped to 18% (normal sea-level air is 21% oxygen). We find that whenever the ODS shuts our heater off, our stove and oven continue to run without a hitch. So, in reality, the stove and oven are actually more dangerous, as they do not have built-in ODS units to shut them off when the oxygen in the room gets too low.

5th wheel camper rv in the snow

A surprise autumn snowstorm at 10,000 feet elevation in Colorado during a two week stay taught us a lot
about how vent-free heaters function at high altitudes.

We use our heater all summer long as we travel through the western mountain states. We find that it works very well at 6,000 to 9,000 feet, taking the chill off cold mornings and raising the temperature inside the RV from a brisk low to mid-40’s to 75 degrees within an hour.

We have spent months at these altitudes. On occasion, if we have been running the stove and oven as well as the heater, the heater will unceremoniously turn itself off. This is no problem. We simply open the RV door to let some oxygen-rich air into the rig.

We have also spent several periods of 10 days to two or three weeks at 10,000 feet. Here we had more difficulty with our vent-free heater when the outdoor temps dropped into the high 20’s overnight (and we got two inches of snow on our roof!) and daytime highs were in the 40’s. The heater needed some coaxing to make it work. We tried two methods of combining the RV furnace and the ventless propane heater at this altitude. Neither was ideal, but this will give you a sense of what to expect and what to try:

1. Run the RV furnace all night long to keep the rig at 50 degrees overnight, and then use the RV furnace to raise the temp to about 60 in the morning. We found that this method used gobs of electricity and propane and didn’t make us very warm. What’s worse, when we tried to use the vent-free blue flame heater after running the furnace, the furnace would not have sufficiently replaced the interior air with exterior oxygenated air, so the vent-free heater could not run very long before it shut off due to having insufficient oxygen around it. So, in essence, using the RV furnace meant we couldn’t use the vent-free heater. We found we could run the RV furnace all day long but the temps in the rig would never exceed 61-62 degrees (the high temps outside were in the 40’s, lows in the mid-20’s).

2. Leave the furnace off overnight and run the ventless propane heater in the morning to warm up the rig. The temps inside our bedroom typically stay about 10 degrees above the outside temps if we don’t heat the RV overnight, so we woke up on some mornings to interior temps in the high 30’s. (We close our bedroom door at night to help keep the bedroom warm). The vent-free heater miraculously heated our indoor RV temps to 70 degrees within an hour of turning it on. At this point, around 70+ degrees, the heater would shut off. We could coax it to run a little more by opening the RV door and fanning the outside air into the rig, but it would shut off again after another 10 minutes or so. So then we would turn on the RV furnace.

Any sensible person would have gone and gotten electric hookups at a campground and run an electric ceramic heater, but we aren’t always very sensible. Camping at 10,000 feet in snowy weather is rather extreme. Most of the boondocking spots we stay at in the summer months are down around 6,000 to 9,000 feet, as I mentioned above, and the heater works beautiful at those altitudes. During the winter months we are typically at elevations of under 1,500 feet and the heater works like a champ without missing a beat.

Note: Since publishing this article, we have enjoyed yet another year of toasty warm heat from our blue flame vent-free heater in the mountains from spring through fall and at low desert elevations in the winter. We were also caught in another even bigger snowstorm on a mountaintop at 10,000 altitude once again and tried a different heating strategy that kept us warmer and dryer. Our article about that experience is here:

How to Heat an RV in Cold Weather and Winter Snowstorms

 

WHERE CAN YOU BUY A VENT-FREE PROPANE HEATER?

We had the worst time trying to find places to look at these heaters and find people knowledgeable about installing and using them in RVs. In some states it is illegal to sell these kinds of heaters (here’s a link to the state-by-state regulations for vent-free gas heaters from ventfree.org), and in mountain towns they are scarce because of their issues with operating at high altitudes. In four months of summer travel when we were looking to buy, we found just two propane gas companies selling vent-free heaters, one in Jackson, MS and one in Kanab, UT. We ended up learning the most from fellow desert boondockers in Arizona, Nevada and California during the winter months and from salespeople in mom-and-pop hardware and RV parts stores in Yuma and Quartzsite, Arizona.

If you know what you want, you can get a much better deal buying online, and Amazon sells all the major brands and accessories. We paid $290 plus $25 tax for our heater, a Vanguard 20,000 BTU blue flame with a thermostat and no blower (it came with feet). After buying, we found the same unit online with free shipping and no sales tax for $175 (Vanguard heaters are no longer made). Ace Hardware told us they could order a similar unit for us, shipped to their store in a week, for $215. So we paid a premium for our unit, but we did talk to a lot of sales people in the process and we saw a lot of the units (and warmed our hands over them), and knew exactly what we were buying.

Cost of installing a vent-free heater

Our entire project cost $385. The heater was $315 (including tax), and parts totaled $70. We were able to borrow the tools, but found they cost only about $15 to buy. We were quoted between $60 and $100 for the labor for the installation. As stated above, we also could have saved about $140 on the heater if we had purchased it online.

 

INSTALLATION OF A VENT-FREE PROPANE HEATER IN AN RV

Following is a pictorial step-by-step guide showing how we installed our vent-free propane heater in our RV.

Installing fIttings on the vent-free propane heater

The installation begins with work on the heater itself…

Working under the kitchen cabinets to install the new gas line for the heater

…however, the bulk of the installation involves tapping into an existing copper gas line to connect a new flexible gas line that goes to the heater.

The first step is to do a little work on the heater itself…

Installing the feet on our ventless blue flame propane heater

Attach the plastic feet so the unit can be freestanding and be moved around the trailer easily.

Installing the gas valve on the blue flame heater

Attach a brass elbow fitting at the base of the heater.
A flexible gas hose will eventually connect to this elbow.

Installing the thermometer on our ventless blue flame propane heater

Attach a thermistor (an electrical resistor type of thermometer) for the internal thermostat. This went on the lower back corner of the heater.

 

Our heater came with feet so it could be freestanding, and it also came with a thermistor, or resistor based thermometer, for the thermostat. These were attached before beginning the actual installation of the new gas line in our trailer.

The brass elbow did not come with our unit, but we found one with the right pitch, thread and diameter at the gas and electric supply store where we bought the other fittings for our project.

Second Step — Turn off the gas and tap into an existing copper gas line

The gas hose for the heater will tap into an existing copper line in a kitchen cabinet

The new flexible gas line for the heater will connect into the existing copper line.

We decided to tap into the copper gas pipe that runs between the refrigerator and the stove at the back of one of our lower kitchen cabinets. Mark measured the pipe and found it was 3/8″.

The goal was to cut the existing pipe and insert a series of fittings that would allow us to attach a flexible gas hose at that point, effectively creating a new leg of flexible gas line. This hose would then run out through a hole drilled at the base of the cabinet and attach to the heater. All of this is low-pressure pipe and fixtures.

Layout of all the gas fittings for installing the vent-free blue flame propane heater in our fifth wheel trailer RV

To create a new leg of flexible hose gas line requires a T-connector (to rejoin the severed pipe), F-F gender changer, On/Off valve and flexible gas hose with a stopper at the other end.

At a gas and electric supply store we picked up a male-male T-connector that would be inserted into the cut copper pipe.

The base of the T would connect to a female-female gender changing connector, and then to an on-off valve (which has male fittings at either end), and finally to a female connector on the end of the flexible gas hose.

Most of the year the heater would not be in use, so we bought a stopper for the end of the hose that goes to the heater.

pipe cutter for cutting gas pipe

Specialty tool #1: Pipe cutter

When the heater is disconnected, this stopper would be screwed into the end of the hose and the heater would be put in a closet.

However, we later discovered we wanted easy access to our heater during all four seasons, so the stopper never gets used!

 

The existing gas line is cut

The existing gas line is cut.

A universal gas appliance hookup kit manufactured by Mr. Heater includes all these parts except the T-connector!

Flaring tool showing both parts

Specialty tool #2: Flaring Tool.

The first step, after turning off the gas, was to cut the pipe. This requires a pipe-cutter, a small, inexpensive tool.

Once the pipe was cut, the next step was to connect the T-connector between the two severed ends of the copper pipe.

practice flare on scrap piece of copper pipe

Practice flare.

This would be done by first sliding a female connector onto each of the two pipe ends and then flaring the ends of the pipe with a flaring tool so the connectors couldn’t slide back off again.

The female connector is slid onto the pipe before the flare is done

The flare prevents the female connector from coming off the pipe.

The male-male T-connector would be screwed into this (and its companion) female fitting on either end of the pipe, rejoining the pipe and making a new connection available for the gas hose to go out to the heater.

flaring tool for flaring the end of a gas pipe

Flaring tool with scrap practice pipe in it.

Mark had never used a flaring tool to flare a pipe before, so he wanted to practice it first on a scrap piece of pipe.

Flaring the real pipe under the kitchen cabinet

Flaring the real pipe inside the cabinet.

He made the practice flare by inserting the scrap pipe into the appropriately sized hole in the tool and then screwing down both ends of the tool to snug the pipe into it — as if it were a bad guy in the old days having his head and hands put in the stocks in the town square!

One flare finished second flare beginning

One flare done, now do the other.

Then he inserted the pointed end of the flaring tool into the end of the pipe and twisted the crank, slowly flaring the end of the pipe as the point pressed further into it.

Two wrenches tighten T-connector in place

Tightening the T-connector with two wrenches

He slid the female connector onto a short piece of pipe and felt a snug fit between the pipe and the connector. The flare was just right. Now confident that he could flare a pipe properly, he contorted himself to get the flaring tool set up on the real copper pipe at the back of the cabinet.

T-connector with F-F gender changer

T-connector with F-F gender changer ready for the shut-off valve to be attached.

He began by sliding a female connector onto one end of the severed pipe under the cabinet and flaring the pipe’s end. Then he did the same thing to the other piece of the severed pipe. Then he screwed the male-male T-connector into the two female ends of the pipe to rejoin them, and he tightened the T-connector using two wrenches.

He attached a female-female connector to the base of the T, making it possible to screw the male-male valve into place. This valve would allow the gas to the heater to be turned on and off. After the valve, he attached the female end of the gas hose.

Connecting the flexible gas hose to the shut-off valve

The new flexible gas line connects to the shut-off valve.

Finally, he drilled a hole in the front base of the kitchen cabinet and ran the gas hose through the hole. The other end of the gas hose was attached to the elbow connector he had placed on the bottom of the heater.

Tightening all the connections with wrenches, and turning the gas to the trailer back on, the heater was now ready to be used.

Hole at base of the cabinet for the gas hose

The new flexible gas line will come through this hole and connect to the heater.

Mark checked for gas leaks using a tiny spritzer bottle filled with a few drops of Dawn dish soap and water. Spraying this mixture on each connection, he looked for bubbles to form which would indicate a gas leak.

To give us flexibility in moving the heater around the rig, we originally used two lengths of gas hose: a 3′ length for under the cabinet and a second 12′ length that attached to it with an inline male-male connector.

Vent-free blue flame propane heater installed in a 5th wheel trailer

What a great little heater!!

The idea was that the 12′ gas hose would give us lots of flexibility for moving the heater around the trailer. However, we found that it was too long and too bulky and the best position for the heater was close to the stove anyway. So we replaced the 12′ hose with a shorter 4′ one.

After the installation was finished, it didn’t seem like such a big project after all, and what a thrill it was to toast ourselves in our warm buggy. Our timing was perfect: the next week brought a big cold front, multiple days of rain, lows in the 30’s and highs in the fifties. We were snug as bugs in a rug while the winds howled outside.

 

There are tons of choices for installing a vent-free propane heater, but these four are among the most popular. If you buy a heater from Amazon, make sure it is PROPANE and not NATURAL GAS, as the pictures look the same. We receive a 4-6% commission for purchases made through any of our Amazon links (at no cost to you) which helps us maintain this site — thank you!

Good luck with your project, and stay warm!

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Disclaimer: This blog post describes our vent-free propane heater installation. We are not responsible for any installation other than the one in our own rig.

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RV Tips – Cleaning Tips for Washing your RV

RV in a car wash

The simplest method to wash the grime off your RV: take it to a car wash with a big bay!

The easiest way to clean your rig is to pull it into a car wash that has an RV bay and go for it. But sometimes car washes with RV bays are hard to find, and moving around on a ladder to get to the high spots is tricky. If you boondock all the time, like we do, and don’t stay in RV parks and don’t ever go home to a house with a driveway and hose, you also don’t have access to handy water spigots.

RV boondocking wash Foam Away

No water needed

So Mark has found some creative ways to keep our rig clean while boondocking.

For a quick job on the truck — if it’s just dusty and not dirty with caked-on mud — he likes to use Turtle Wax Foam Away, a dry wash that doesn’t require water.

Spray it on and wipe it off, and your truck is nice and clean. Sadly, this product isn’t available any more, but another great alternative is Dri Wash ‘n Guard Waterless Car Wash.

RV boondocking RV wash Zip Wax

Add a spritz to 2-3 gallons of water

RV boondocking wash and wax meguiars quik detailer

Shine up the rig

For more stubborn dirt and stains, like the bugs that splatter on the front cap of the fifth wheel and the hood of the truck, or for a more thorough wash, Mark makes up a bucket of sudsy water using a couple of gallons of water and Turtle Wax Zip Wax Ultra Concentrate

He washes down one area at a time and then wipes it dry. No rinsing necessary.

Mr Clean Magic Eraser Scrub Pads

Mr Clean Magic Eraser Scrub Pads

The neat thing about boondocking is that you have tons of space around your rig, so he drives the truck around the fifth wheel, lining it up to reach the highest spots on the trailer.

A ladder works too, but the truck gives him a much wider lateral reach as he walks along the side of the truck bed. It’s a little acrobatic, but that’s makes the job more exciting!

One awesome product Mark discovered is Mr. Clean Magic Eraser Pads. These things do an amazing job of getting rid of the scuff marks on the fiberglass front cap on our fifth wheel.

Boondocking RV wash use the truck

Better than a ladder…

RV boondocking uv protect all

Sunscreen for the plastic parts

For quick waxing he prefers Meguiar’s Quik Detailer (others like Mr. Clean’s Spray Wax work too). This is a polish detailer that gives the truck and trailer a nice shine and leaves the fifth wheel front cap and truck hood so smooth the bugs don’t stick (at least not for a while).

To get a little UV protection on rubber seals and plastic (like the translucent plexiglass hatch covers, a/c unit and fridge vent) he uses Protect All, a UV protectant. He has also used 303 Aerospace Protectant, which seems to work equally well. And of course the truck windshield gets a dose of Rainex every so often.  Rainex makes rain on the windshield bead up and slide off more easily so the wipers can be used a little less — although we’ve found it seems to be most effective at preventing rain from falling all together, that is, until the Rainex has worn off and the windshield needs another coat!

Boondocking RV wash Meguiars paste wax

For a more thorough wax job

Once a year Mark uses Meguiar’s Gold Class Paste Wax on the both the truck and trailer to give them a deeper finish and prevent oxidizing. If there is oxidation or stuck on bug pieces that just won’t come off, he uses Meguiar’s Cleaner Wax, a cleaner/polisher that has a mild abrasive in it.

Over the years Mark has tried lots of different cleaning and polishing products, and they all get the job done. Far more important than using a particular product is just getting out there and applying some elbow grease with whatever you have on hand. Doing a little bit more frequently is easier than doing a big job all at once…!

California Duster

California Duster

When the rig just needs a quick dusting (the truck especially), Mark turns to his trusty California Duster.

This thing is amazing because it picks up all the dust and can later be shaken out with a few quick twists of the wrist.

And that’s all there is to it. Easy peasy — especially for me, since on those rig washing days I always find I am suddenly very busy doing something else!!

And, ironically, after each of the photos of our buggy getting a bath on this page was taken — in a car wash in Montana and while boondocking in Colorado — it rained for 3 days in each place.  So go ahead — do the RV rain dance and help end the drought!!

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New to this site?  Check out the RVing Lifestyle and Tech Tips in the MENUS at the top of the page for detailed info about installing solar power, installing a vent-free propane heater, living the full-time RV lifestyle, how to go boondocking, how to find free campsites, the costs of full-time RVing and more.  Please visit our Home page and Welcome page for RVers to learn more about us and discover all the other good stuff available to you on this blog.

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