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How Much Solar Power Do I Need For My RV?

We get it—upgrading your RV or camper with solar power is a big decision. You're looking at the dozens of panels available, and the choice is overwhelming. How much power do you need? How many panels, and what size? What can you run on solar?If you've asked yourself any of these questions, or if you've done some research and found the technical explanations of volts/watts/amp-hours clear as mud, we're here to help clear things up and help you find the best solar setup for your camping needs. Check out our solar calculator here, or read on below for a solar power breakdown. If you're still on the fence about a solar investment, check out our article, 4 Reasons Not to Use Solar Power in Your RV (And 4 Reasons You Should), to get a better idea if solar power is for you.
Solar power comes down balancing the two main parts of the power equation:
  • Power Used: (the amp-hours you use each day)
  • Power Stored: (the energy your solar panels provide to your battery)
For help determining how to do this, read on below.
Watch Now: How Much Solar Power Do You Need?

Power Used: How Much Power Do I Need for Camping?

It's important to go into your solar power setup knowing what you need (and what you don't). You can plaster every inch of your camper with solar panels, but this is ultimately a waste of money if you have nowhere to store all the energy the panels produce. On the other hand, underestimating the number of panels you need can mean running out of power or being forced to use your generator when you'd rather avoid it.If you find that your battery doesn't last as long as you need it to, you can add to your battery bank to increase your capacity. It's important to check your camper's size and weight capacity when adding additional batteries.So how much battery capacity do you need? To determine this, you need to calculate how much energy you use in a day. There are a couple of ways to do so.
How Much Power Do I Need for Camping - Infographic
Reading Your RV Battery: How Much Power Is Left?Figuring out how much energy you use in a day means looking at your battery and determining how charged (or not) it is. You never want to drain your lead acid battery lower than 50%, as this can damage the battery and shorten its lifespan. Monitoring your battery sounds pretty simple until you realize stock RV battery voltmeters don't provide the most helpful information. If you have one of these, you'll see numbers like "12.6," or "12.3," which tell you pretty much nothing if you don't know what you're looking at. Basically, a fully charged RV battery will put out about 12.6+ volts. An RV battery at 50% battery will put out between 12.06-12.10 volts, on average. If your voltmeter has a number below this, charge your battery immediately. If you're going to be boondocking a lot, however, it's definitely worth investing in a decent battery monitor or gauge if your RV didn't come with one. There are a lot out there, ranging from very simple models to state-of-the-art battery management systems. At the least, you want to look for a system that will provide a simple charge percentage indication. It's a lot more straightforward to simply have your monitor tell you your batteries are at 80% than to try to figure out what 12.4 on the voltmeter means. Once you know how much power is actually left in your RV (either by checking the voltmeter or by reading the battery monitoring system), you can use this information to determine how much energy you use per day using one of the two methods below.
Redarc Manager30 Battery Monitoring System
Pictured: Battery information provided by the REDARC MANAGER30 battery monitor.

Method 1: Use Our Solar Calculator

If you prefer to spend less time doing math and more time camping, check out our solar calculator. We've done all the complicated bits for you, so all you have to do is answer a few simple questions and let us recommend the right kit for you.

Method 2: Do the Math Yourself

This is most people's least preferred method. It involves estimating your daily power consumption while RVing, adding up the total, and using the sum to determine how many solar panels you need. There are dozens of calculators and printable sheets online for this purpose, most of which look something like this:
Calculate Watts Used Per Day
The problem with this method is that you're left to estimate how many watts your appliances use and how many hours a day you use them. Most of us don't walk around our campers with a stopwatch and time how long it takes us to fix a cup of coffee, or use our hair dryers, or charge our phones. These numbers can also vary. Maybe you usually watch an hour of television a day, except if it's raining, in which case you may spend the better part of an afternoon watching movies in your RV. Even if you find the wattage stamped on your appliances, or if you take a reading with a battery monitoring kit, you'll still have to estimate how many hours you're using your items each day.All things considered, this just isn't the most accurate or reliable method for determing how much power you use.

Method 3: Go Camping and Try It Out

The best way to figure out how much energy you output is to actually go camping. (This is also more fun than a spreadsheet.) If you can make multiple camping trips, even better. Follow these simple steps to determine how much power, on average, you consume in a day:Step 1: Settle out in the boondocks for a couple of days and use your RV as you normally would—don't try to conserve power any more than you usually would, and don't use your generator. Just camp normally.Step 2: Use your voltmeter or a battery monitor to keep track of your battery level. Note that lead-acid batteries should never be discharged below 50%. Going below this mark will shorten the battery's lifespan. Step 3: Do the math to determine how much power you typically consume in a day. Let's say after two days, your 200 amp-hour lead-acid batteries are at 50%. This means you used 100 amp-hours in two days, or 50 amp-hours a day. NOTE: If you can't even make it through a day without draining your battery, consider adding to your RV's battery bank. All the solar panels in the world won't help if you don't have enough battery capacity to store the power you require. Ideally, you should be able to go at least 2-3 days before your battery is depleted.
Energy Saving TipsWhen boondocking, it helps to get in the habit of conserving energy. Try these tips below:
  • Use LED bulbs
  • Unplug electronics when not in use (phones, tablets, etc.), or charge them while driving if possible
  • Adjust your daily routine - read during daylight hours, vacate the camper during the day instead of using fans, etc.
  • Replace older TVs with efficient, LED flat screens
  • Shorten your shower time
  • Park under shady trees or use your awning to keep cool; conversely, layer up to keep warm

Power Stored: How Many Solar Panels Do I Need for Camping?

So now that we know how solar power works and how much power we need per day, we can ask ourselves the big question: how many solar panels do we actually need for camping? Well, how much power does a single solar panel produce? The answer is, it depends.If you prefer not to use our solar calculator, you can use the chart below for a recommended kit and common battery requirements to get started. Or, if you'd prefer a more detailed explanation of solar output and tips on estimating your panel needs, read on below the chart.

RV Solar Kit Recommendations

Amp Hours Needed (Per Day)Solar Kit Rec. (DC)# 12V Batteries
27.42 aH 80W Eco Kit 2
158.85 aH 760W Solar Kit 4-6
Amp-Hours Needed (Per Week) Solar System Rec. (DC + AC) # 12V Batteries
"Solar Sizing Calculator." gpelectric. Accessed 3 Jan 2019.*Amp-hours are based on 6 hrs. usable sunlight per day.

Solar Panel Efficiency

Solar panels are rated for their max efficiency—that is, a 100-watt solar panel will produce 100 watts in perfect conditions. (And unless you're the luckiest camper in the world or have discovered a way to control the weather, we guarantee you won't always have perfect conditions.)The weather, temperature, time of day, and other factors influence the amount of power solar panels actually generate. There are multiple online calculators available that take your geographic location, the time of year, etc. into account and provide the average usable hours of sunlight you can expect.

Tips for Estimating RV Solar Panel Needs

Although actual output may vary based on the factors mentioned above, you can get yourself to a ballpark figure using a couple of tips. The general rule of thumb is that a 100-watt solar panel can produce about 30 amp-hours per day, so you can use this guideline to determine about how many panels you need. Another suggestion is to match your battery capacity in amp-hours with your solar output in watts. A 300 amp-hour camper battery, for instance, would need around 300 watts of solar power. Also keep in mind that solar panels experience a 75-90% drop in efficiency on cloudy days, so it's good to have slightly more than you need when it comes to solar power (about a 20% cushion, if possible, to account for less-than-ideal conditions).

Determining How Many Panels We Need (Examples)

We're going to jump back into the math one more time (it turns out everyone's eighth grade math teacher was right—we do need this stuff).In our example from the last section, we know that we use 50 amp-hours per day when camping in our RV. We want to keep our battery at optimal charge, so we're going to need a solar setup that can generate this same amount of power per day. If we look at Go Power's 100-Watt Retreat Solar Panel as an example, we can see that its power output is 5.43 amps per hour.If we assume 6 usable hours of sunlight per day, that's 32.58 amp-hours per day, which is pretty close to our ballpark figure of 30 amp-hours per day. From here, we can determine that two of these 100-watt panels would give us about 65.16 amp-hours a day, which covers our requirement of 50 amp-hours. Our two 100-watt solar panels equal 200 watts together, which also checks out with our guideline of matching our battery amp-hours with our solar panel wattage. We even have our 20% "cushion," though if we want to add a smaller panel for faster charging or to help pick up the slack on cloudy days, we can do that too.
RV Solar Panel Estimation Tips
How Many Solar Panels Does My RV Need - Infographic 1
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Related ArticlesRelated ProductsWritten by: Amber S. Updated on: 2/8/19

Scott W.


It makes a huge difference whether the panels are in direct sunlight or shade; are you going to park in a wooded campground? Our 300W solar panel system puts out about 10..20W in a wooded campground. We went for the 12V / 120V all-electric fridge (oops); if we're in shade we have to run our (quiet) generator twice a day to charge our 100 Ahr battery. Going to add a second 100 or 200 Ahr now that prices have dropped, add a battery monitor.

Etrailer Expert

Mike L.


@ScottW Great point, thank you!



We are going to boondock for 12 - 18 months in Washington state. We have a travel trailer that runs on 50amp. We would like to purchase a system that will allow us to run the 15,000 btu A/C, 7 gal water heater, StarLink throughout the day, LED TV, 2 laptops for work 8+ hours a day and led lights in the travel trailer. How large of a system would we need? Thank you

Andrew J.


can you get solar power from the moon?

Scott W.


@AndrewJ technically yes, given that we see the moon by sunlight reflected from it However you won't get a significant amount of power.
Etrailer Expert

Mike L.


@ScottW True.



We purchased an older 33ft trailer and plan on boondocking with it. We want to install solar panels on it. How many 100w panels do I need? iv e seen videos of people having 4 -1oow up to 6-100w solar panels. Once i figure that out, how can i tell if my current Electrical panel is good enough?

David B.


Let me get some more info from you. What type of RV is it 5th wheel or travel trailer. What state are you camping in? How many days do you plan on camping? What battery type do you have in the RV and how many? What is the amp hour rating per battery? What appliances do you have and how much do you use them?

John H.


@Dan The number of solar panels you will need/want will depend on how much power you plan on using. As a general rule, about 200 watts of solar will support 3-4 days with moderate electrical usage. I define moderate as a couple hours of tv, charging a laptops or phones, making a pot of coffee, and running lights for a few hours. If you plan on heavier usage such as running a fridge, microwave, several hours of television/radio, several hours of lights, then you will want around 500-600 watts of solar. I attached a solar calculator you can use to see which of our kits will work best for your specific needs.

Mike M.


I didn't hear any stories about running your furnace at night. We camp with people who run the furnace at night and generator by day just to stay charged. I have used the furnace only to wake up to dead batteries. I just bought a used rv that is wired for solar but no equipment installed. I'm also very interested in 6v batteries. I just want to do this once....

David B.


We have a new solar calculator that I think will help you out! Follow the link and use the guide to plug in your information about power needs and it will give you a couple solutions and suggestions to what system will provide the power you need. If you have any questions about the system it suggests let me know and I can help you out from there.



@DavidB this calculator says I need 66,700 that per day? I put it that we would be on solar the whole year. I have been trying to figure out what size system I need as we live in our trailer full time in Florida and when it comes to hurricanes I would like to have solar back up that we could run everything we need and be ok until power is restored.

Scott W.


@MikeM look into your battery system too; you didn't say what kind or age your existing batteries are. Remember you can only run lead-acid down to about 50%, unless a greatly reduced cycle life is acceptable. The charging system has to be compatible with the type of battery. E.g. a lead-acid charger will destroy LiFePO4 batteries. The one you have might be settable or auto-adapt.
See All (4) Replies to Mike M. ∨



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