Solar on rv roof
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What’s your roof got to do with it?
Getting started on the process of RV solar requires knowing what assets you have to work with. One of the biggest assets an RV owner has is free uninterrupted roof space. Learn how to maximize open spaces and fit your solar panels into the open areas you have to work with. The more solar you can add will mean the more DC electrical power you can produce. This is why it is important to put on your thinking cap ahead of time and create an RV solar panel layout.
The items are just the main ones that can and will break apart your RV roof into smaller less usable spaces for solar panels:
- Air Conditioners
- Vents
- Fans
- Drain Plumbing Vent Pipes
- Skylights
- TV Antennas
- Exhaust Fans
- Satellite Antenna
- Roof Racks
- AM/FM Radio Antennas
- Port Holes
Panel layout requirements may cause the need for more cabling
Keep in mind that some RVs will have obstructions that require panels to be placed some distance apart. It may require you to order additional MC4 extension cables to make the necessary connections.
You can download a copy of our New Updated Solar Layout Guide Below
This kit has now been updated to include the new Go Power 190 watt solar panel kits. This guide will be really important when looking at kits like the AE-4 and AE-6.
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Update underway now to add the new Go Power slim 100 solar panels to the layout guide.
Shop Go Power Slim Rv Solar Kits and Expansion panels
The slim models may be what you need to increase your off-grid solar output. As the slim panels hit the market. You will find more and more offerings for them.
The newest style of solar panels is flexible ones that can confrom somewhat to the shape of the RV roof. These panels range from 20 watts to 110 watts. Many of the flexible panels have inreased in wattage due to their use of more efficent cells in the same panel footprint. Go Power! has a wide range of the panels and the most popular size is the [110 watt flexible solar kit](/go-power-100-watt-flexible-solar-kit-gp-flex-100/). Go Power 110 Watt Flexible Solar Kit Go Power 110 Flexible Expansion panels There are many brands and sizes of these flexibles today. Every year more and more efficent panels with better qualities hit the market. you can also look at thin film flexible solar panels as well. These panels are more flexible but typically have a lower power density.
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Flexible Solar Panels for RVs – Pros, Cons, and Best Ones To Buy
As those of you who’ve followed us for a while know, we’ve got an extensive solar system on our motorhome consisting of a combination of both rigid and flexible solar panels. When we originally installed the flexible panels for our RV, we weren’t entirely sure how they’d perform from day to day, but we’d done a fair amount of research and we were hopeful that they’d become an integral part of a successful solar array… providing the power we need to stay off-grid for extended periods.
Our rigid solar panels are capable of being tilted, and that’s a real bonus for power-hungry full-timers like us. But flexible solar panels can do things rigid panels can’t. So, today we’re looking at flexible solar panels for your RV – the benefits, the drawbacks, some important notes, and some of the best flexible panels available on the market today.
- 1) What Are Flexible Solar Panels?
- 2) What is the Difference Between Monocrystalline and Polycrystalline Solar Panels?
- 3) What Are the Benefits of Flexible Solar Panels for an RV?
- 3.1) Flexibility
- 3.2) Lightweight
- 3.3) Easy to Install
- 3.4) Fewer Holes Drilled/No Mounting Brackets Necessary
- 4.1) Less Efficient
- 4.2) Heat
- 4.3) Durability/Lifespan
- 4.4) Expensive
- 7.1) Adhesive Backing
- 7.2) Velcro
- 7.3) Screws
- 7.4) 3M VHB Adhesive Tape
- 7.5) Eternabond Tape
- 8.1) Xantrex Flex Max 165W Solar Kit
- 8.2) Renogy 100 Watt 12 Volt Extremely Flexible Monocrystalline Solar Panel
- 8.3) SunPower 110 Watt Flexible Solar Panel
- 8.4) Renogy 175-Watt 12-Volt Flexible Monocrystalline Solar Panel, 175W
What Are Flexible Solar Panels?
Flexible solar panels are encased in flexible, slightly bendable plastic. In this way, they differ from rigid solar panels that have their solar cells encased in glass.
The top of a flexible solar panel is clear, allowing the sun to penetrate it, reaching the solar cells and enabling them to produce electricity.
Inside a flexible solar panel, thin electrical wires connect the solar cells to an MC4 or similar connector on one end of the panel. This allows the panel to be connected to another panel (either in series or in parallel) or to the solar controller that sits between the panel and the RV’s battery bank.
Xantrex flexible solar panel kit with charge controller and MC4 connectors. (Photo credit: Xantrex via Amazon)
What is the Difference Between Monocrystalline and Polycrystalline Solar Panels?
The difference between monocrystalline and polycrystalline solar panels is in the solar cells themselves.
Polycrystalline solar panels contain cells that are made of multiple silicon crystals. They’re less efficient than monocrystalline panels, and also less expensive. If you’ve ever seen a solar panel with blue cells – meaning the top of the panel is blue – you were looking at a polycrystalline solar panel.
Polycrystalline cells (on the left) have a characteristic blue cast to them, while monocrystalline cells (on the right) look black (Image Credit: Wikimedia)
Monocrystalline panels have black cells that are made of single crystals. These panels cost more initially, but they’re more efficient than polycrystalline panels. Because a monocrystalline solar cell is composed of a single crystal, the electrons have greater mobility, allowing them to generate a greater flow of electricity.
So, while you’ll pay more for monocrystalline solar panels, you’ll also be getting more efficiency for your money… or getting the same power output in a smaller footprint.
What Are the Benefits of Flexible Solar Panels for an RV?
Solar panels offer a number of benefits in an RV application. Let’s take a look at some of the advantages of flexible solar panels for your RV.
Flexibility
First, of course, is their flexibility (it is, after all, in their name!). This is actually a very important consideration depending on where you want to locate your solar panels.
For example, flexible solar panels can bend to follow the curve of an Airstream or other RVs with curved roofs.
Some RVs have limited rooftop space for solar panels, and flexible panels can be easier to maneuver around space constraints.
Even folks with very large rigs who want to maximize their ability to install solar panels at various angles benefit from the flexibility of flexible solar panels.
For example, our dear friends Tom and Caitlin Morton (of Mortons on the Move) installed 10 flexible solar panels on the roof of their fifth wheel, and 2 additional flexible panels on the front cap of the RV. You can read all about their off-grid solar panel installation, but they’ve found that in the shorter days of winter (when the sun is low in the sky), the panels on the front cap are particularly helpful. The flexibility of their stick-on flexible solar panels is the reason they were able to install panels in that location at all.
Flexible solar panels installed on the cap of Tom and Caitlin Morton’s fifth wheel. (Photo credit: Tom Caitlin Morton, Mortons on the Move.)
We installed our flexible solar panels on the roof of our motorhome because, with everything else we’ve got mounted up there, we needed some thin, light, flexible solar panels to share the space.
So, the flexibility of flexible solar panels makes them incredibly versatile.
We should note that flexibility can be a drawback as well. Over-bending a flexible solar panel can damage the solar cells dramatically, so care needs to be taken when handling them prior to, and during, installation.
Lightweight
Flexible solar panels weigh considerably less than rigid solar panels, another significant advantage.
All RVers work to keep the weight carried by their rig down in any way possible. Flexible solar panels can weigh as much as 80% less than rigid solar panels, which is a very significant weight difference. And that difference can allow you to install a larger solar array on a smaller RV that doesn’t have the weight carrying capacity of, say, our large Class A diesel pusher.
Easy to Install
Flexible solar panels are very easy to install. Many actually come with an adhesive backing, but either way, the installation of flexible solar panels is a breeze. You simply clean the area where the panel will lay, stick the panel down, and surround the edges with a good sealant tape like Eternabond. That’s it!
There’s no easier way to install solar panels on your RV.
Fewer Holes Drilled/No Mounting Brackets Necessary
Another advantage to flexible solar panels for your RV is the fact that fewer holes need to be drilled into the roof because no mounting brackets are necessary for the installation. And the fewer holes we put in an RV, the better.
Here you see the flexible and rigid solar panels installed on our motorhome.
In general, an array of flexible solar panels will probably require a single hole drilled, for at least one pair of wires to enter the interior of the RV and connect to the solar charge controller. This of course depends on your particular installation. There are RVers out there (particularly those with self-built camper vans) who’ve installed flexible solar panels without drilling a hole at all. And many other RVers take advantage of the roof vent for their RV refrigerator to run the solar wires into the RV without drilling any new holes.
But generally speaking, most installations will find a single hole drilled for wiring, and that’s all. This is a significant advantage over multiple mounting bracket holes being drilled for rigid panel installation.
What Are the Downsides of Flexible Solar Panels for an RV?
As with anything else, there are downsides to using flexible solar panels, and it’s up to the individual RVer to determine whether the upsides outweigh the downsides or vice versa, based on their particular application.
Let’s take a look at the disadvantages of flexible solar panels for your RV.
Less Efficient
In general, flexible solar panels are slightly less efficient than rigid solar panels. This is because flexible panels are so thin that they contain far less material for sunlight interaction/absorption. Due to the thin design of a flexible solar panel, the silicon wafers are pared down to a width of just a few micrometers.
Flexible solar panels also tend to use less efficient semiconductor materials, so they’re not as efficient at turning sunlight into electricity. While rigid solar panels have roughly 16-20% efficiency, flexible panels by comparison have anywhere between 7 and 15% efficiency. This of course depends on the panels, their placement, and other factors, but it also means that each flexible panel gives you less energy than a similarly sized rigid panel, so you’ll need more/larger flexible panels to get the same amount of energy you’d get from a rigid panel.
Heat
Due to the fact that there’s no airflow under flexible panels that are stuck directly to the roof, there’s less heat dissipation. So the solar panels themselves get very hot. Solar panels can get as hot as 150 degrees during the summer, depending on your location. And because hot solar cells don’t perform as well, this impacts the solar efficiency of flexible panels even further.
Our Xantrex Flex Max 165W flexible solar panels are electrically almost identical to the Xantrex 160W rigid panels we installed alongside them. Under identical conditions (lighting, temperature, wind, sun exposure, etc… including tilt angle, since we have the ability to tilt our rigid panels), the flexible panels output approximately 5-10% less power than the rigid panels do because of the heat buildup on the flexible (even when not tilted, the rigid panels sit about 1-2″ above the roof surface, allowing air to flow beneath them).
Our tilted rigid panels and our flexible solar panels soaking up the sun – and the heat!
Additionally, that accumulation of heat can, over time, reduce the lifespan of the panels themselves. So flexible solar panels may not last as long as a traditional glass panel would in the same situation/conditions.
Heat retention can also be an issue on the surface where the dark flexible panels are mounted, creating a situation where heat is pulled into the RV on hot summer days (some people worry about the potential for that heat to damage the underlying roof material, but we haven’t heard of any instances where that’s been the case).
Some RVers try to mitigate the heat issue to some degree by installing their flexible panels using various techniques (velcro, PVC piping, etc) in an effort to allow the panels to dissipate some heat while still holding the panel securely to the surface. But all of that additional work/effort is undoing much of the benefit of the ease-of-installation of flexible panels.
Durability/Lifespan
The durability/lifespan of flexible solar panels tends to be decreased as compared with rigid panels, which means that you may be more likely to have to replace the flexible panels before you’d need to replace rigid ones.
This may or may not be an issue for you, and most RVers who install flexible panels probably don’t worry much about the lifespan issue. In general, rigid solar panels are projected to last anywhere from 25-40 years, while flexible panels might last 15-25 years by comparison, (although flexible panels are relatively new to the market, so we don’t have as much real-world data to know for sure how long they’ll last).
Expensive
Flexible solar panels are more costly to buy than their rigid counterparts, mainly because the technology used to produce flexible panels is newer. You could, in fact, pay 2-3 times as much for a flexible solar panel as you would for a rigid solar panel of the same power output.
With that said, the installation of flexible solar panels is likely to be less costly than the installation of rigid solar panels unless you contribute all of the labor yourself either way.
Can Flexible RV Solar Panels Overheat and What Happens if They Do?
Flexible RV solar panels can indeed overheat. Generally speaking, however, they’re tested to withstand very high temperatures and should be perfectly fine in virtually all situations. But it IS possible for a flexible panel to overheat to the degree that the plastic laminate can burn.
This is in addition to the loss of power and the reduction in voltage values that will result from overheating.
Can You Walk On Flexible RV Solar Panels?
It is not recommended to walk on flexible RV solar panels, regardless of what the manufacturer may say. Scratching/scuffing of the surface will reduce the efficiency of the panel by reducing the amount of light that reaches the cells. And the stress of your weight can crack the solar cells themselves, potentially significantly reducing the output of the entire panel, or causing it to fail altogether.
How Do You Install Flexible Solar Panels on an RV?
There are several different ways to install flexible solar panels on your RV. Generally speaking, most people use one of the following methods of installation.
Adhesive Backing
As we mentioned above, many flexible solar panels for RVs come with an adhesive backing already installed (ours did). This makes installation a breeze.
Velcro
With this method, a commercial-grade/industrial strength Velcro is used to adhere the panels to the surface. This method can allow a bit of airflow under the panels as it lifts part of the surface of the panel off the roof to the degree of the thickness of the Velcro. But it also means that water and dirt/debris can get underneath the panels as well, leading to the potential for mold/mildew to grow.
Screws
The edges of some flexible solar panels have rivets that allow for the panels to be screwed into the roof. Some people may prefer this method of installation, while others would prefer to avoid making any unnecessary holes in the roof.
3M VHB Adhesive Tape
Once the surface has been cleaned and prepared for installation, VHB tape is laid in place and pressure applied to create a good seal (fair warning – removing the VHB tape is not for the faint of heart!). VHB tape comes in various widths and lengths.
Eternabond Tape
Eternabond is another very strong tape used by many people who install flexible solar panels on RVs. This tape forms a very strong bond and can be laid around the perimeter of the flexible panel for a solid seal. (Removing Eternabond also requires heat and some fairly heavy-duty elbow grease to remove, so plan accordingly.)
Once the panels have been successfully installed on the surface, you’ll need to connect them (if you’re installing more than one) and create an entry for the wires to be directed into the bay or area where your solar charge controller is located. You may or may not need to drill a hole for this purpose, because you may have an inlet nearby through which you can feed the wires (like your RV’s refrigerator vent).
If you don’t have an inlet available through which to run your wires, you’ll need to create one either by drilling a hole through your RVs roof or by giving the wires access in some other way.
Finally, you’ll connect the wires to a solar controller which will then be connected to your battery bank.
This process is made more or less complicated depending on how many solar panels you intend to install, but we’ve got a pretty hefty 1,300-Watt solar system, and we did our own installation with the help of our friend Brian of RV with Tito who has some great solar installation videos on his site.
Here’s our ultimate 8-panel, 1,300-Watt solar system explained, but remember – we’re full-timers who live and work off the grid regularly, so we need a robust system.
What Are Some of the Best Flexible Solar Panels for an RV?
Xantrex Flex Max 165W Solar Kit
These are the flex panels we have. While they definitely come at a premium cost, they’re extremely well-made, efficient, and durable. They’re more robust, thicker, and sturdier than any other flexible solar panels we’ve ever seen, by far.
These panels have peel-and-stick adhesive nearly to the edges and don’t require any additional taping with Eternabond, VHB tape, or any other adhesive.
We’ve experienced no issues with water, nor have the panels experienced any loss of adhesion in the thousands of miles we’ve driven, and the numerous rainstorms we’ve experienced, since installing them.
We’ve been very pleased with these panels and their output. They’re working very well for us and, after several years of full-time exposure to the sun and elements, show no signs of aging or degrading.
Xantrex offers a 5-year product warranty.
Can I Connect a Solar Panel Directly to an RV Battery?
Solar power has taken over the RV world. It’s hard to find an RV that doesn’t have at least one small solar panel mounted to the roof or sitting outside.
If you dry camp, having a solar panel connected to the RV battery is a really simple way to keep the batteries charged so you can run the basic necessities like lights, the water pump, and the fridge.
Related Product: We use the reliable VMAX 100Ah AGM battery (click to view on Amazon) in our RV.
The more power you use the more solar panels and battery storage you are going to need.
In this article, I will outline the simplest way to get solar power to your RV battery.
This isn’t a guide for large RV battery banks with inverters connected to them. This is more for the average camper who wants a panel that can keep one or two RV batteries charged.
When solar panels for RV batteries first came out they were very small, up to 5 watts. They could be connected directly to the battery because they weren’t outputting much power. Much like a trickle charger.
The larger solar panels that are being used today require solar charge controllers between the panel and the battery.
The charge controller is basically a Smart charger that regulates the power from the solar panel.
It makes sure the batteries are being charged safely and it will even turn off the power when the batteries are full so you don’t have to physically disconnect the panel from the battery.
Charging RV Batteries with a Solar Panel
I recommend having at least one 100 watt solar panel for charging RV batteries.
It’s a practical size that should be enough to keep the batteries charged for running the basic 12 volt appliances in a camper.
The good news is that with this setup you can easily add another panel if you end up needing more solar power.
There are lots of different ways to connect a solar panel to an RV battery. You can get as complicated as you want with it.
My setup is meant to keep things as simple as possible. It’s the most direct way to run cables from a roof mounted solar panel to RV batteries.
This was done on a travel trailer that had the batteries stored on the front in battery boxes.
It might be a little different for 5th-wheels and motorhomes that usually have the batteries stored in a compartment instead of out in the open.
The concept is the same though, and figuring out where to mount the charge controller and where to run the wires will be the most difficult part.
One thing that has to be done is the solar charge controller needs to be protected from the elements.
That means you need to keep it in a watertight box like we did, or it needs to be mounted inside a storage compartment.
When we switched to a motorhome we were able to mount the solar charge controller inside because there was a hole already drilled into the floor that had cables running directly to the RV battery compartment.
It will be a little different for everyone, but here’s our simple way to connect a solar panel to RV batteries.
List of Parts
Here’s a list of everything we used for this solar panel setup.
Products Used
(click links to view on Amazon)
- Renogy 12 Volt 100 Watt Solar Panel
- Renogy Voyager 20A 12V/24V PWM Solar Charge Controller
- Renogy 20A Fuse Block
- Renogy Solar Panel Mounting Z Brackets
- Roofing Screws with Rubber Washers
- 10AWG Solar Extension Cable w/ MC4 Connectors
- 10AWG Battery to Charge Controller Cables
- Cable Tubing (for protecting solar cables that are exposed to the road)
- EternaBond RV Roof Seal
- Butyl Tape
- Self Leveling Lap Sealant (can be substituted with EternaBond)
- Caulk/Sealant (for sealing holes made for solar charger cables, you can also use EternaBond tape in certain cases)
- Weather Dust Proof Box (not necessary if you’re planning on mounting the charge controller inside a protected area like a storage compartment)
Tools Used
- Drill
- Caulk Gun (if using self leveling lap sealant instead of EternaBond Tape to seal roof screws)
- Philips Screw Driver
- Wire Stripper
- Box Cutter
- Saw (for cutting the handles of the battery boxes so the charge controller box would fit.)
Other Optional Products
We bought everything we used in separate parts, but Renogy also makes a solar charger kit (click to view on Amazon).
This kit includes a 100 watt solar panel, roof mounting brackets, 30 foot solar extension cables, 8 foot solar charger to battery cables, and a 30A charge controller.
The included charge controller is just a slightly larger version than the 20 amp one we used. It also has a Bluetooth feature that makes it so you can see your battery levels and the solar input from your phone.
Both Voyager models are compatible with all battery types, including Lithium and SLA batteries.
This kit does not come with a fuse. If you want to use one you will need to purchase one separately.
If you want to be able to angle your solar panels to follow the sun you can get this Renogy roof mounting kit (click to view on Amazon).
It has foldable legs you can use to tilt up the solar panel. It can also be folded down so it lays flat on the RV roof for travel.
Steps for Installing a Solar Panel onto an RV Roof
Find a Good Spot on the RV Roof
When deciding where you should install the solar panel on your RV roof there are a few things you will need to consider.
First, where are the RV batteries and where will the solar charge controller be?
You want to put the panel on the part of the roof that’s closest to where the cables will need to go.
In the case of our travel trailer that was the front of the RV since the batteries and the charge controller were located on the tongue.
You also want to think about the other things on the RV roof. If you put the panel right next to the RV AC it might block the sun.
Putting the panel in a spot where it will get the most sun for as long as possible is important.
If possible you also want to be able to find where the roof supports are so you can screw the solar panel into a solid spot.
We found that finding the roof studs was harder than we thought it would be. The stud finder didn’t work because there are multiple layers of rubber and wood on an RV roof.
We did the best we could and so far we haven’t had any issues with the solar panel staying on the roof.
Since both roofing screws and butyl tape was used to mount the panel a lot is keeping it in place.
Attach the Roof Mount Brackets and Butyl Tape
Once you have a general idea of where to put the solar panel on the RV roof you can attach the mounting brackets to the panel.
Put a piece of butyl tape on the bottom of every bracket. It’s important to use sealant tape when putting anything on an RV roof.
It not only seals the roof and keeps water out but it also acts as an adhesive and helps keep the panel mounted securely to the RV roof.
Connect the Solar Extension Cables
You will be able to connect the solar extension cables at any time using the MC4 connectors but it’s easier to do it before the panel is secured to the roof.
I zip tied the cables underneath the solar panel so they would stay in place.
That way there won’t be any pressure put on the connection box under the solar panel and the MC4 connectors will always be protected underneath the panel.
Screw the Solar Panel onto the RV Roof
You can also skip this step and do it last.
In the picture above you can see the butyl tape that’s between the bracket and the RV roof. It’s spreading out and sealing the holes being made in the RV roof by the screws.
Even though everything should be nice and sealed up because of the butyl tape and the rubber washers it’s still highly recommended to use a second sealant on the top of the roofing screws.
We used self leveling lap sealant but since doing this project I’ve started using EternaBond tape.
Since you should already have Eternabond tape I recommend cutting off a strip and covering the entire foot of the bracket, including the heads of the screws.
But you can also use self leveling lap sealant like we did.
Now the 100 watt solar panel should be fully installed on the roof of your RV.
It’s time to set up the extension cables and the solar charge controller.
Installing Connecting the Solar Charge Controller
Run Solar Extension Cables to the Charge Controller
We wanted to make this installation as simple as possible. So instead of finding a way to get the solar extension cables to the charge controller inside of the walls, we ran the cables down the outside front of the travel trailer.
I used some PVC cable hiders on the roof to not only secure the solar cables but to also help protect them from the sun.
After doing this installation I’ve since decided that using EternaBond tape to secure and protect the cables would have worked even better.
EternaBond is not only extremely good at sticking to everything, but it also has a special outer layer that is resistant to the sun and more durable than plastic and PVC.
I also used PVC cable hiders for the cables going down the front of the travel trailer.
Once again EternaBond is a fantastic and more durable alternative to PVC cable hiders, but the downside is it’s much harder to remove.
For the bottom half of the camper, I switched to black cable tubing to protect the extension cables from the road.
I secured the cables and cable tubing to the bottom of the RV where the plywood floor was accessible. I was able to use a cable clamp (click to view on Amazon) and a regular screw.
Since the charge controller is going to be mounted between the RV batteries we were able to secure the extension cables from the solar panel to the 12 volt power cables.
Connect the Charge Controller (Electrical Box Method)
If you don’t mind drilling a hole large enough for the solar cables to fit through in the floor of your RV you can install the charge controller inside the front outer storage compartment.
It’s a good spot for a charge controller because it’s watertight and it will be easy to check the charge controller whenever you want.
We didn’t want to drill any holes in the floor of our travel trailer because we wanted our setup to be easy to remove.
Instead, we mounted the charge controller in a waterproof PVC electrical box that fit perfectly between the two RV batteries.
If you want to mount the charge controller inside your RV or a storage compartment the way the cables are set up will basically be the same.
You will need longer cables for the controller to battery connection.
Prep Battery Cables
You need to be able to connect the cables from both the battery and solar panel to the charge controller before mounting it.
Use 10 AWG cables with battery lugs on one end and open wires on the other.
Since the charge controller is mounted right next to the batteries we didn’t need very long battery cables.
If you mount the charge controller further away you will need to get longer cables to reach.
Not everybody uses fuses but it’s recommended to have a fuse between the battery and charge controller.
We used a Renogy 20A Fuse Block (click to view on Amazon) but any 20 amp inline fuse works.
We chose the fuse size based on the amps the cables can handle.
Put the fuse on the positive cable that will be between the battery and the charge controller.
We installed the fuse so it could sit inside the electrical box with the charge controller so it would be protected.
Connect All Cables to the Charge Controller
After you set up the cables that connect the batteries and make sure they can reach you can connect them to the proper terminals on the solar charge controller.
Make sure you thread the cables through the electrical box first.
We drilled two 1/2″ holes in the electrical box that could fit 2 cables each. We used 2 small holes instead of a big one so there would be less space to seal with caulk.
Mount the Charge Controller Inside the Electrical Box
Use small screws to mount the charge controller inside the electrical box.
The end result should have the charge controller and the 20 amp fuse inside the box.
Use caulk or EternaBond tape to seal the holes in the bottom of the electrical box so no water can get inside.
Secure the Charge Controller Box.
There was just enough space for the electrical box to fit between the two RV batteries after we sawed off the inside plastic handles on the battery boxes to give the electrical box enough space to fit.
The battery and solar panel cables come out of the bottom of the box.
Connect the cables with the battery lugs on them to the same battery terminals the RV cables are connected to.
You want to charge the RV batteries from the same terminals power is being drawn.
Our travel trailer is powered using two 12 volt deep cycle batteries connected in parallel.
That means the positive cable from the charge controller will be connected to one battery and the negative to another.
Adjust the Charge Controller for Your RV Batteries
Most advanced charge controllers, like the Renogy Voyager 20A 12V/24V PWM Solar Charge Controller (click to view on Amazon), can charge most kinds of batteries.
But the different battery types will have different settings for optimal charging.
Follow the instructions for your specific charge controller to match the kind of batteries you have connected to it.
Routinely Check the Charge Controller Solar Panel
If everything was set up correctly and the connections were done right the solar panel should be able to charge the RV batteries without you needing to do anything else.
But to be safe I recommend checking the charge controller routinely to make sure it’s set correctly, charging the RV batteries, and still being protected by the electrical box.
Also, check the solar panel now and again to make sure it’s still secured tightly to the RV roof and clean.
Have any questions about installing a solar panel to charge the RV batteries? Leave a comment below.
by Jenni
Jenni grew up in a small town in Idaho. With a family that loves camping, she has been towing trailers since a very young age.
5 thoughts on “How To Install Solar Panel On RV Roof Connect To Battery”
hello! I would like to know what you think about the flexible panels that are glued directly to the roof of vans and motorhomes, best regards Reply
Hi, They are great if you use high-quality panels that can handle extreme temperatures without burning. A lot of the cheaper models aren’t made with materials that can handle the heat while being glued to a surface. I’ve been told to only use flexible panels with an ETFE layer, so if you’re the one buying the panels make sure it has that. Reply
great, thank you very much, I am deciding whether to put a roof rack with a rigid solar panel or a flexible one and I can’t decide, in Spain it can be very hot at noon, I only have to buy a 200 w solar panel, so it will be the best quality you can find Reply
Excellent article. Very simple. Exactly what I was looking for. My question is, can you use the power directly from the solar panels instead of just batteries? Does the charge controller switch between the batts and panel power? Thanks in advance. Reply
Hi, Unfortunately, I don’t think there is a solar charge controller that can do that. Its job is to regulate the voltage from the panel and charge the battery safely. It can’t regulate the voltage and supply a steady 12V to an RV for example, and charge controllers don’t work without a battery. It is possible to power some 12V electronics directly with a solar panel with the use of a step down converter, but that’s not something that should be connected to an electrical system in an RV. Reply
How To Mount Flexible Solar Panels On an RV The Right Way
RV owners are increasingly switching to solar to take advantage of its energy savings and off-grid capabilities. Out of all the different types of solar panels available, many are turning to flexible photovoltaics.
Flexible solar panels maximize the surface area of your RV’s roof. They have incredible flex, making them easy to mount on curved and irregular-shaped surfaces.
If you want to install flexible photovoltaics onto your RV, you’ll need the right equipment and step-by-step instructions.
Find everything you need to do it the right way here.
What Equipment Do You Need To Mount Flexible Solar Panels on an RV?
The equipment you will need depends on the installation method you choose.
First, is the roof of your RV rigid or made of canvas?
For obvious reasons, there are different installation approaches for canvas and rigid roofs.
Since RVs with solid metal or fiberglass roofs are more common, this article will FOCUS on the best way to install flexible solar panels on a solid surface.
When installing photovoltaics on a rigid roof, there are several methods and mounting materials to consider.
You’ll need the flexible photovoltaic (PV) panels first. Options like the EcoFlow 100W Flexible Solar Panels are lightweight and can flex up to 258°. They’re excellent for mounting to curved and irregular surfaces. And unlike most thin-film flexible solar panels, they have an industry-leading efficiency rating of 23%.
With very few exceptions, you can’t connect solar panels directly to your appliances or RV electrical system. You’ll also need a portable power station, power kit, or other balance of system (BOS).
Typical BOS components required by any off-grid solar power system include:
You can build your system piece-by-piece using separate components from different manufacturers. Going DIY can be a challenge, especially if you don’t have extensive experience building electronics. And it’s easy to run into compatibility issues between manufacturers’ components and solar panels.
Many people avoid the hassle by buying a plug-and-play solution like EcoFlow’s solar generators. Solar generators include a PV panel(s) and a portable power station — everything you need to get off-grid electricity generation up and running.
EcoFlow’s portable power stations, like the DELTA 2, offer AC/DC and USB-C charging in addition to direct solar input, so you’ll always have options to stay charged on the go.
Now that we’ve explored what you need in addition to flexible solar panels for them to function, let’s look at the step-by-step installation.
Luckily, it’s relatively easy!
How To Mount Flexible Solar Panels on Your RV
Once you’ve purchased your solar panels and portable power station, it’s time to install the panels.
It’s crucial to remember that flexible solar panels alone can only produce a minimal amount of electricity. For most applications, you’ll want to combine them with rigid solar panels, which are easy to permanently mount on level surfaces — like your RV’s roof.
Here we’ll FOCUS on flexible solar panel installation only — step-by-step.
Purchase the Right Tools
With EcoFlow’s flexible solar panels, there are two easy installation methods. One is to screw them directly onto the exterior of your RV using a drill or screwdriver. The PV panels come with six pre-drilled holes — one in each corner and 2 in the middle on either side of the frame.
One of the main advantages of flexible solar panels is their lightweight, low-profile build. If you’d rather not drill into your RV’s exterior, you can permanently affix them to your vehicle using silicone-based adhesives like SG20 or Fix8. Or a double-sided acrylic foam tape like 3M VHB Tape. This isn’t a viable option with heavier-weight, thicker rigid solar panels.
Plan Your Solar Panel Layout
Lay out your flexible panels and mark their locations on your RV’s roof with colored tape or a wax pencil.
Avoid areas where a satellite dish or air conditioner could cast shade.
Also, leave about 0.79 inches (20 mm) between each panel if you install multiple panels so that you can interconnect the panels with cables.
Mount the Flexible Panels
Screw Mounting: Position the solar panel where you want it mounted. Using a pen or marker, make a marker through each of the predrilled holes in the panel. Use the appropriate sized drill bit to predrill your holes on the RV. Screw your panel into the holes on the RV using a screwdriver or power drill and the right size Phillips or flat head screws. It’s usually best to screw in the diagonally-opposite corners first, as this will help ensure the panel stays in place as you screw in the other holes.
Silicon or Double-Sided Tape Mounting: Using your silicon-based adhesive or VHB tape, apply the adhesive in strips running the entire panel width beneath each cell gap.
Don’t apply the adhesive around the edges of the panel, as this can trap air under the panel. Air s can expand when the panel heats up, damaging the panels and the RV roof.
Interconnect All Panels
Whether you have multiple flexible panels or a combination of flexible and rigid options, you’ll need to connect them all before connecting them to the portable power station. You can connect them in series or in parallel, depending on how you want to regulate the voltage or amps.
Connect All Panels to the Portable Power Station, Power Kit, or BOS
Once you have installed all your solar panels, and connected them in series or parallel, simply connect your array to the portable power station or other balance of system.
Connect the Portable Power Station to the RV
For all of your DC power needs, run wires directly from the power station to the fuse box in your RV.
You can run an AC power strip and extension cord directly from the portable power station for all your AC power needs — like your refrigerator, TV, hot water kettle, laptop, smartphones, and other electronics. You can also plug each appliance directly into one of the AC outlets on the station itself.
Also, after you connect the power station directly to your fuse box, any AC outlets in the RV should also have power.
The LCD on your portable power station will display charge levels and electricity usage. You can also monitor and control everything from your smartphone using the EcoFlow App.
Why You Should Consider Using Flexible Solar Panels on an RV
Flexible solar panels offer distinct advantages for RV owners. Here are some to consider.
Using Flexible Solar Panels Maximizes Available Surface Area
Flexible solar panels let you maximize the surface area of your RV’s roof to produce more electricity. Since they are flexible, you can install them on curved roofs and other irregular surfaces that wouldn’t accommodate a rigid PV array.
Many people use a combination of flexible and portable or rigid solar panels alongside off-grid RV power solutions like the EcoFlow Power Kits. With a modular power kit, you’re free to customize your setup however you want to meet your energy needs.
Flexible Solar Panels Are Easy to Mount
Flexible panels are much easier to mount because of their lightweight and flexible design. Unlike large and heavy rigid panels, which require mounting hardware, you only need industrial silicon adhesive or high-strength VHB tape with flexible arrays.
Flexible Solar Panels Easily Connect With Other Solar Panel Types
Flexible panels combined with rigid and portable panels can cover all your energy needs while traveling off the grid.
Additionally, interconnecting all PV panels is an easy process you can do yourself.
FAQs
Is Installing Flexible Solar Panels on Your Own Worth It?
Installing flexible solar panels and setting up your own renewable energy system can save you money if you have DIY experience. However, be sure you know what you are doing. Mistakes can be costly and cause damage to your equipment. Combining flexible with rigid solar panels can be slightly more challenging to install on your own.
Should You Use a Professional To Install Flexible Solar Panels?
If you have any doubts about installing your flexible PV panels, consult a professional and pay them to do the installation for you. The cost of paying for a solar power system to be professionally installed on your RV can easily end up being less expensive than damaging your
Final Thoughts
Flexible solar panels are an excellent addition to any RV solar power system. They’re easy to mount on curved, irregular-shaped surfaces to maximize energy production. They produce less electricity than higher rated power wattage rigid and portable solar panels, but they are ideally suited to augmenting them.
Flexible solar panels are also a fine standalone if your off-grid electricity needs are minimal.
If you’re ready to build a custom solar power system for your RV, consider EcoFlow. We have multiple solutions for RV owners, from flexible and rigid solar panels to power stations, solar generators, power kits, and more.
EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.