The number of solar panels needed for RV boondocking depends on how many batteries you have to keep charged, and what appliances you want to power. You’ll need to add up the total Amp Hours (AH) your batteries are capable of holding, along with the wattage requirements of your appliances.
How Many Solar Panels Do I Need for Boondocking?
With respect to your batteries…
- If you have a single 12 volt battery, at about 100 AH, you should have 300 watts of solar panels, minimum.
- With two 12 volt batteries, or two 6 golf cart volt batteries, with between 200-250 AH, you should have 400 watts of solar panels, minimum.
- If you have four 12 volt batteries, or four 6 volt golf cart batteries, with between 400-600 AH, you should have 600 watts of solar panels, minimum.
These recommendations are based on the metric that you can produce 30 AH of battery charge using a 100 watt solar panel, between 5-9 hours of sun exposure. The typical solar panel found on most RVs range from 150 watts to 200 watts.
Running Your Appliances Day and Night
- If you want to run just the basic RV accessories during the day (LED lights, ceiling fans, power awning, water pump, refrigerator*, furnace*, water heater*, power jack), along with a few electronics plugged into your 120 volt wall sockets (television, laptop, cellphones) then you should be able to get by with 300 watts of solar panels, along with a single 12 volt battery.
- If you want to also power your RV’s built-in furnace all night long, then add a second 12 volt battery, or better yet upgrade them both to two 6 volt golf cart batteries. You might still be able to get by the same 300 watts of solar, but 400 watts should cover you.
- If you want to also add a 1,000 watt microwave oven to the above, then upgrade to two 6 volt golf cart batteries, and get a minimum of 400 watts of solar.
- If you want to also add a coffee maker, Instant Pot, toaster oven, blender, food processor… Then upgrade to either four 6 volt golf cart batteries, or two 100 AH lithium batteries, and get at least 600 watts of solar.
- If you want to be able to run all of the above during periods of cloudy weather, upgrade your solar panels to about 1,200 watts.
Note that the above recommendations are all minimums. When it comes to solar and battery, bigger is always better.
* These appliances normally run on propane or 120 volt power, however they still have control panels and igniters that run on battery power.
Roof Mounted Panels vs. Ground Panels
Roof-mounted panels won’t deliver their advertised wattage. A 100 watt panel will actually only deliver between 50 to 75 watts. This is because roof-mounted panels are not capable of being tilted to face the sun at the ideal 90 degree angle. And because they’re on the roof, people often forget to clean them. Meanwhile, solar panels that sit on the ground can be tilted and turned to face the sun at a 90 degree angle. They also tend to be kept clean more often, and thereby get the maximum wattage.
Roof mounted panels are popular because you can “set them and forget them”. Meanwhile, you have to manually place ground panels in the direction of the sun, and hook them up to your solar charge controller. You may have to turn the panels and tilt them throughout the day. Ground panels may also run the risk of being stolen, and can fall over in strong gusts of wind.
Can I Use Solar Power to Run the Air Conditioner?
Technically, yes. You’ll need a bigger battery bank, capable of holding at least 600 AH, to run a single AC unit for about four hours. You’ll also need at least 1,200 watts of solar panels to recharge those batteries quickly and efficiently enough to bring your batteries up to charge to keep you powered through the evening. But because of how many watts a 15,000 BTU air conditioning unit consumes, it remains impractical to power it from battery. Nearly all RV boondockers still rely on a generator of at least 3,600 watts to run a single AC unit.
For Further Reading
A more technical discussion on how many solar panels can be found at “The Boondoctor” at, “How Much Solar Do You Need For Your RV?“
want to have a solar set up that is flexable , and connected to battery to store power. basic use for fridge, charging phone, computer, occasional lights/tv use. just not sure how much amh and solar panels needed . help.September 13, 2020 at 4:50 am
Kristin, your demands are very much within the realm of many other RVers. 600 to 800 watts of solar is a perfect range for your needs, with 200 amp hours of battery if using deep cycle AGM or flooded cell, or 100 amp hours if using lithium.September 13, 2020 at 6:09 pm
I wish there was more data on efficient appliances — and more options for installing them on an RV.
If boondocking a long time, it’s nice to have enough solar panels to avoid bringing along gas & propane (for generators & heat & absorption fridges). But for now, propane has so much more energy density it’s hard to live without it.
DC compressor fridges are pretty efficient — but still uncommon and use a fair bit of battery power.
Efficient split AC units might use 70% of the power of an inefficient standard RV rooftop AC. And they can double as an efficient electric heater if it’s cold.
I don’t think heat pumps water heaters will ever be good for RVs. They just heat the water too slowly (I don’t know about everyone else — but I only turn on the water heater when I need hot water. It’s cold and not using power the rest of the time).
It would also be nice to see data on what extra insulation, shade, rv skirts, etc have on the energy budget.
Solar panels (or a smaller generator) would be far more practical without wasting so much energy.February 9, 2021 at 12:42 pm
From all the videos I’ve watched ‘buying the best to start with is the best option and will save money in the long run.’ How do I know which is the best? I’m planning on buying a vintage camper, but propane makes me uneasy. I’d like to be totally self-contained with solar. The solar suitcase panels seem most affordable, but which backup(?) battery do I need to go with it?June 19, 2021 at 8:29 pm
We will be living full time in a TT in Phoenix so plenty of sun all year. We don’t plan on much dry camping. Are generators or Solar best option? There are two 15,000 BTU air conditionersAugust 10, 2021 at 11:07 am
Generator is better than solar if you want to run two 15,000 BTU air conditioning units. A single 15,000 BTU air conditioning unit will need a generator that can generate at least 3,500 “surge watts” just to kick start the unit. Once it’s running, the unit probably only needs about 1,500 watts to run. But if you have two air conditioning units, you will need a larger generator. You will need one that can produce a minimum of 5,000 surge watts to get both air conditioning units running, but you will have to start them one unit at a time. That would leave you with no power left to run anything else. If you want to run a microwave oven while running both air conditioning units, then add another 1,000 watts to your generator. If you want to also run a medium-sized Instant Pot at the same time, add another 1,000 watts. If you want to watch television too, add another 100 watts. If you want to power your other electronics, add another 100-150 watts.
As an alternative, you can modify your air conditioning units to add “soft starts” to each one. This will allow the unit to kick on more slowly, using less power. With a soft start, you can kick on a unit with just 2,000 watts of power, but it will still need about 1,500 watts to keep it running. Just about any RV shop can install these. Micro Air makes a line of soft starts called “Easy Start”, here is an [Amazon Link] to them.
That being said, I would shoot for a generator that can produce about 6,000 surge watts and about 5,000 running watts. That should provide enough power to run two air conditioning units, plus a microwave oven, an Instant Pot, and a television.
The downside is that generators of this size are noisy. You will have to maintain a lot of distance from other campers. They are also very heavy. You will not be able to get it inside your travel trailer. It will have to remain in the bed of your pickup truck, and you will need a couple of guys to help you get it up there. Once it’s there, you just leave it there, and secure it with straps. Get a topper or tonneau cover for your truck bed to keep the rain off of it.
Also, if your travel trailer has a 50 AMP port, then make sure to get a generator with a 50 AMP outlet.
Champion makes excellent generators that don’t cost as much as the Hondas or Yamahas, but are built better than most brands and come with good customer support. I have a Champion Generator 8750/7500, here is an [Amazon Link] to the one I have.August 10, 2021 at 1:21 pm
There are different methods on how to compute your recreational vehicle’s power requirements. One of these methods is to go camping for a few days without utilizing your AC generator.August 24, 2021 at 7:20 am
I’ve decided to upgrade my RV with solar power, and I don’t know how many solar panels are needed. Thank you for writing this, your information is very helpful to me.October 18, 2021 at 7:47 am
To figure out how much solar electricity an RV with a lot of appliances needs, figure out how much wattage is utilized on a daily basis. This avoids the energy scarcity that stops us from even turning on the lights.November 30, 2021 at 7:35 am
Solar panels come in varying wattage ratings, ranging from 100 watts to 300 watts. Newer solar cell technologies offer higher efficiency ratings, with some products producing as much as 415 watts per panel.March 10, 2022 at 2:34 am
I have 700 watt panels on rv shed roof and 4-32aph batteries and one 100aph battery what will be a good controller can I use ,I am running a small TV, water pump, a few 12volt lights,small microwave,raidio,maybe a toster?and frig. That will be 24/7April 25, 2022 at 8:22 pm
Hi, I just wanted to double-check the estimated requirements. I have a trailer with 2-100 amp lithium batteries for a total of 200 amps. On average, I consume 75-100 amps per day. Can I get by with 300 watts of solar panels? This is the most I can fit on the trailer roof. If I am reading this correctly, it would be touch and go.May 11, 2022 at 12:27 pm
John, yes 300 watts of solar on the roof will be plenty for your requirements. It sounds like the panels alone may provide enough power for your needs. The two lithium batteries you have might only be needed at night.May 11, 2022 at 4:07 pm
Hi. I’m renovating a van. It’s quite small(imagine a short bus). I have a fridge, water heater, small devices, 12 led lights but my concern is my space heater. At 1000w I’m concerned 300w of solar won’t be enough to keep me warm in the winter. I have currently 3x 100w solar panels to mount on the roof and 100ah battery. Advice would be greatly appreciated.October 7, 2022 at 3:53 am
Sam, that 1,000 watt space heater may only run for about 1 to 2 hours with your battery and solar panels. There are a lot of variables to consider. If your battery is either a “flooded cell” or “AGM” type, then you actually only have about 50 to 70% of usable battery capacity. That is, a fully charged battery usually pushes out 12.7 to 13.0 volts, and once it reaches 12.0 volts it struggles to produce enough power. That 12.0 volt mark usually means your battery is already down to 30 to 50% capacity. So realistically, a 100 AH battery is actually just 50 to 70 AH.
A lithium battery, however, will offer you the full capacity. It will maintain is 12.7 to 13.0 volts all the way down to 0% capacity. Thus, a 100 AH lithium provides a full 100 AH.
The other big issue is sunlight. Obviously, during the winter, you will have fewer sunshine hours. Moreover, if your panel is mounted on the roof, then it will be at a poor angle to the sun. Thus, a 200 watt panel may only gather about 60 watts. On top of that, it may take a full 8 hours of day light just to recharge your battery.
If you want to run an electric heater, then you are going to need more batteries, preferably lithium batteries, and a lot more solar panels. I would suggest getting four (4) 100AH batteries, and about 800 watts of solar (minimum), in order to run that electric heater for about 8 hours. You will still need to turn off the heater for about 6-8 hours during the day to recharge the batteries.
Your best solution to all this is to run propane heaters. You can buy the full size Mr. Heater for a couple hundred bucks. You will also need to buy at least two 5-gallon propane tanks, along with the “Mr. Heater Hose” to connect the tank to the heater. That 5-gallon tank will last a full day of non-stop use, and it will heat your bus a lot better than an electric heater.
Your other (better) solution is to buy a small generator, about 2,000 watts. This will cost you about $500 to $600. It can power that electric heater for about 8-10 hours on a full tank, and that tank will hold about 1-gallon of gas. At that point, all you need is a 5-gallon gas can (or a couple of 2-gallon cans if your not strong enough to lift 5-gallons). I seriously recommend getting a generator of at least 2,000 watts, or else I do not recommend boondocking in freezing weather without one.October 7, 2022 at 11:34 am
Question for all I am new to the RV living,
I have a 2020 Keystone montana 3790rd 5th wheel, how many panels will I need to power entire rig with both A/C units, fridge, electric fireplace?December 12, 2022 at 9:09 pm
I am installing 4 possibly 5 200 watt monocrystalline solar panels on my RV roof. I plan to use AGM batteries or similar to keep costs down. I have heard 120ah batteries can be difficult to top off. Is this really a concern and how big should my battery bank be? Am also looking for a cost effective MPPT controller, planning to use my rv’s factory 55amp inverter. Thank you !December 18, 2022 at 4:46 pm