Charge Your RV Battery With Solar Panels When Boondocking/Dry Camping
I travel fulltime in my travel trailer and spend 95% of my camping nights boondocking, also known as dry camping. To recharge my RV batteries I use solar panels.
Today I want to share a couple of solar panels that you can use to recharge an RV battery with when you’re boondocking.
Since we all have different needs, I will list a couple of different sized solar panels. I’ll also do my best to give you an understanding of how much a solar panel can generate, and what to look out for.
There are also two ways to go when it comes to solar panels and battery charging, the portable way and the more permanent way. The portable way is with a portable solar panel that you can take out and connect to your batteries as needed, and the more permanent way is installing solar panels on the roof of your RV/van.
I wouldn’t call either of those two ways hard or advanced, but a permanent install takes more work and wiring.
Small Solar Panel Setups
This kit from Suner Power is a small solar panel kit that can be seen as both a portable and a more permanent solution. It comes with a 50W solar panel, a 10A solar charge controller, and several different connectors depending on how permanent you want the installation to be.
You can use the alligator clips if you want a temporary set up, the terminal rings if you want to be able to quickly connect the panel when you get to your campsite, or the bare wire connector to wire it to a different connector.
Suner Power makes an adjustable solar panel mount rack that you can as either a kickstand on the ground or screw into an RV/van roof and tilt as needed.
There are smaller kits available if all you’re looking for is a trickle charge.
I like the kit since it gives you options, and it includes an efficient monocrystalline solar panel that will do a great job at keeping your RV battery charged when boondocking.
This kit by Renogy is for more permanent installations. It’s a 50W kit that comes with a 10A PWM charge controller, Z brackets for mounting, MC4 to ring terminal connectors, and 20ft MC4 to bare wires that will connect the charge controller to the solar panel.
Renogy uses high efficient monocrystalline panels with 21% efficiency.
The kit comes with everything you need to set it up, but you might want some MC4 extension cables depending on far the solar panel will be mounted from the charge controller. Since the charge controller isn’t waterproof, it should be mounted where water won’t get in.
Installing a kit like this is more permanent and takes more work to set up than a portable panel, but once it’s set up you’re done.
If you would rather have a lightweight foldable solar panel, the Acopower 50W might be the one for you.
It comes with a 5A charge controller that has a USB port to charge your electronics with, while also charging your 12V camper batteries.
What makes it so portable and lightweight is the fact that it’s a bunch of flexible panels instead of a solid panel. It weighs less than six pounds, while a solid 50W panel weighs about 10 pounds.
A built-in handle makes it easy to carry the panel when it’s folded, and a bag on the side stores the charge controller and alligator clip wires when not in use.
To connect the charge controller to your camper battery, you’ll use the included alligator clips. Connect the positive (red) clip to the positive terminal on your battery, and the negative (black) clip to the negative.
Medium Solar Panel Setups
I have two of these Renogy 100W suitcases and two 100W solar panels on my camper roof. The reason I went with two portable suitcases and not 400W on the roof is that I wanted to be able to move the panels around and angle them to generate the most electricity.
In the morning, the evening, and in the winter when the sun is low on the horizon, flat panels on your roof won’t generate very much electricity. I can tilt my roof panels, but that requires me to get up there and do it.
I set these suitcase panels up when I get to camp, then leave them out for a week or as long as I am boondocking at one site, and turn them during the day to face the sun. These generate a lot more power than my roof panels due to this.
You can connect one of these 100W suitcases with the included alligator clips. It also comes with a carrying case, a waterproof 10A charge controller with a display that tells you data, a kickstand, a handle, and a fuse between the charge controller and your battery.
For boondocking, it’s hard to beat a portable panel like this.
The downside with portable rigid panels like this is the weight.
If you want a lightweight 100W portable panel, Dokio has you covered.
This is a foldable panel with two 50W monocrystalline panels. The size and weight make it very easy to deal with, although it won’t be as sturdy in the wind compared to the Renogy suitcase above.
Included with the Dokio solar panel are a charge controller and alligator clips. All you have to do is connect the solar panel to the charge controller, and the alligator clips to your RV battery.
The charge controller has USB ports so you can charge your phone, tablet, lights, and speakers while recharging your camper batteries.
It’s a lightweight (5.2 lbs) portable setup that will keep RV batteries charged when boondocking.
Similar to the Renogy solar kit we looked at above, the 100W solar starter kit comes with everything you need to install the solar panel to the roof of your RV or van.
You can choose between a 10A, 20A, 30A, or 40A charge controller, and whether you want a PWM or MPPT charge controller. MPPT is the better option due to charging efficiency.
Since a 100W panel only generates about 6 amps an hour, it might seem excessive to pair it with a 30A solar charge controller, but it gives you the option to easily upgrade the system in the future.
A flexible solar panel like this can be installed to an RV/van roof without drilling any holes. It can be taped down since it’s so lightweight, it will stay there.
This kit from a company called Xinpuguang comes with a 10A charge controller, MC4 wires, and alligator clips.
To set it up, you connect the MC4 to bare wire to the solar panel icon on the charge controller, then the alligator clips wires to the battery icon. Connect the alligator clips to the battery, then connect the MC4 connectors from the solar panel to the MC4 connectors from the charge controller.
A big reason to go with a flexible panel over solid ones is the weight difference. This panel weighs around 9 pounds, and a solid 100W panel weighs around 20 pounds.
The downside with flexible panels is that they’re not as durable, and will scratch easier.
Large Solar Panel Setups
Renogy has a lot of kits depending on how much solar you want. This 200W kit is an upgrade compared to the one above with the included fuses and Bluetooth module that lets you monitor the system on your phone.
It comes with a 20A MPPT charge controller that will charge your RV batteries efficiently, and do a much better job compared to a PWM charge controller during the morning, evening, and on cloudy days.
In addition, it comes with brackets, and the cables you need to wire the panels to the charge controller.
The Renogy 200W Eclipse Suitcase is the best most efficient portable solar panel on the market right now.
It’s heavy and large at almost 42 pounds but will do a great job at recharging your 12V batteries when you’re boondocking. It connects to your RV battery with alligator clips and has a waterproof 5-stage 20A charge controller so you can leave it out in bad weather.
An included carrying case will protect the panels while it’s in storage, and the handle makes it easy to carry.
It’s a plug-and-play system that will generate about 60 amps in total on a sunny day.
What You Should Know
It can feel overwhelming when it’s time to choose a panel. To help you out, here are the main things you need to know. I go more in-depth about these in my post “How big of a solar panel do I need to recharge RV batteries?“.
- You should always have a solar charge controller between the battery and the solar panel. The charge controller protects the battery from overcharging. MPPT is to prefer over PWM charge controllers since they’re more efficient when the sun is weaker (morning, evening, cloudy days, wintertime). Each of the solar panels I recommended above includes a solar charge controller.
- A 100W solar panel is usually enough for most. One 100W solar panel generates about 6A per hour or 30A per day (on a sunny day). So if you only need to power the water pump, furnace/kitchen/bathroom fans, 12V TV, and possibly USB devices, a 100W panel should be more than enough.
- If your RV batteries are the deep cycle lead-acid type (heavy, car batteries), a general rule of thumb is to keep that battery above 50% to not do permanent damage to it. If you have lithium batteries, like the ExpertPower LiFePO4 (click to view on Amazon), you can discharge them lower.
Frequently Asked Questions About Solar Panels
How Do I Connect The Solar Panel To My Battery?
The solar panel connects to the solar charge controller, which then connects to the battery.
Most charge controllers have icons that show you where the positive/negative wire from the solar panel and battery goes.
With Renogy’s kits, the solar panel will be connected to the charge controller with MC4 connectors. This adds a quick-connect between the panel and the controller.
Some kits want you to connect the solar panel wires directly to the charge controller without a way to quickly disconnect the two.
Depending on the solar panel kit, you’re going to connect the charge controller to the battery with either alligator clips, a quick-connect input on the side of your camper, or with ring terminals.
Alligator clips and quick-connects are the temporary way and the ring terminals are the more permanent way. You can, of course, disconnect the ring terminals when you want as well, but it takes longer to unscrew the ring terminals versus removing the alligator clamp.
Connect the positive (red) clamp or ring wire to the positive terminal on your battery. Then connect the negative (black) clamp or ring wire to the negative terminal.
I recommend connecting the charge controller to the battery before connecting the solar panel, to give the charge controller a chance to read the voltage of the battery.
How To Install Solar Panels To An RV Roof
You can either mount your panels by screwing into your roof or by using 3M VHB tape.
How we mounted our panels
We mounted our Renogy panels with screws. First, we located the studs in our roof with a stud finder. Then we installed the mounting brackets on the solar panel, put it down on the roof, and marked where the holes were going to go.
Next, we predrilled the holes, put Dicor butyl seal tape under the mounting brackets, and screwed the brackets into the roof.
The last thing we did was to put Dicor Self-leveling lap sealant all around the screw holes, to stop any water from getting in.
How we pulled the wires
We pulled the wires through our fridge vent, down through the back of the fridge, and then into our trailer. We’ve wired our panels directly to our solar generator, so they’re not connected to our battery.
How you wire the charge controller to the battery the easiest way depends on the layout of your camper. You’ll have to be creative to make the wires as short as possible to prevent power loss.
A common solution I have seen is to mount the charge controller in a storage compartment where it won’t get wet, then pull wires either through a wall or underneath the camper to the batteries.
How Big Of A Solar Panel Do I Need To Recharge RV Battery?
How Many Amps Does A 100W Solar Panel Generate?
On a sunny day, a 100W solar panel generates about 6 amps per hour, or 30 amps a day.
If it’s cloudy, this number will obviously be much lower. To generate as much electricity as possible you should angle the panel towards the sun. I also recommend using an MPPT solar charge controller instead of PWM.
What If My RV/Travel Trailer/Fifth Wheel Is Prewired And Has A Zamp/Furrion Solar Port?
I have written two separate posts about how to connect solar panels to a prewired trailer.
Can I Combine Two Or More Solar Panels?
Yes, you can combine two or more panels in either a series or a parallel connection.
When combining two or more panels in series, the amperage stays the same, but the voltage doubles or triples depending on how many panels you use. Combing panels in series mean connecting the positive MC4 connector to the negative MC4 connector on the second panel, so the positive and negative cable going to the charge controller is from different panels.
The second way to combine panels is in a parallel connection. This doubles the amperage, but the voltage stays the same. To do this, you combine the positive wires with one MC4 Y Branch (click to view on Amazon). Then you combine the negative wires with the second Y Branch. This specific adapter lets you combine two panels in parallel, but there are larger ones available as well for combining three or more panels.
A parallel connection keeps the positive separate from the negative.
What Are The Best Solar Panel Brands?
Renogy, HQST, Newpowa, Acopower, GoPower, Zamp, and Eco-Worthy are some great solar panel brands.
What Is A Solar Generator/Power Station?
Will The Solar Panel Power My RV Outlets?
No, a solar panel generates 12V DC power, while RV outlets power 120V AC electronics.
To change the 12V DC power into 120V AC power, you need to use an inverter like this. When this box is wired to a charged 12V battery, it can be turned on and power two AC outlets. You could then run extension cables to power your electronics.
A 1200W inverter like the one I linked to will not power an RV air conditioner or microwave. The 1200W/2400W rating means that it can power devices up to 2400W for a short time, but only 1200W continuously.
Please leave a question down below if you have any questions.