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How Much Solar Power For A Camper Van? An Easy Calculator

Learn to calculate how much wattage your solar array needs to be to support all the electronics in your camper van. Keep reading to learn more.

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How Many Solar Panels Do You Need For Your Camper Van?

When installing a camper solar system, one of the first questions we must ourselves is, “How much solar do I need for my camper van? 100 watts? 300 watts? More?” This is a difficult question to answer accurately because everyone’s needs are different. What is the best solar size for one person may not be the best for you.

In truth, your ideal solar power size depends on your power requirements. The more power you intend to use in your camper van, the more solar you will need. The good news is that you don’t have to do any difficult calculations to identify how many watts of solar you need to install.

Google docs sheets screenshot that calculates solar wattage size for camper vans.
Solar size calculator spreadsheet

In this post, you can download our solar array size calculator. It’s a free resource that will help you identify the following pieces of information:

  • Minimum solar wattage size
  • Fuse & circuit breaker sizes
  • Ideal solar wire sizes
  • Solar charge controller size

Let our solar size calculator do all the work for you.

So if you’re ready, let’s dive into it!

But First...

Size Your Battery Bank

The calculations in our solar spreadsheet assumes you have a properly sized battery bank. If you just randomly bought a battery without taking into account the electrical devices in your camper van, the solar size calculator will not work for you.

Therefore, we strongly recommend download our leisure battery calculator first and taking the time to properly size your battery bank. To get started, read our leisure battery size calculator post.

1. Download Solar Calculator Spreadsheet

Download the free solar calculator to get started. The document is available in both Google Docs and Microsoft Excel file formats. (But the Google Docs version is better.)

To start calculating your ideal solar wattage, download our free spreadsheet. The document is available in both Google Docs and Microsoft Excel file formats. (The Google Docs version has a better user interface)

2. Read Pink Information Box & Delete

When you open the document, you will be met with an interface similar to the image below. Follow the directions in the pink text box and delete the box when you’re ready to begin.

If you opened the Google Docs version you need to make a copy of the document and save the file into your own Google Drive directory. If you don’t do this you won’t be able to edit the document.

If you opened the Microsoft Excel version you can start making edits right after opening.

3. Battery Bank Size (in Amp-hours)

In Step 1, you will need to fill in the two boxes shaded in green. They are:

  1. Battery bank size (Ah) – Here you will enter the size of your battery bank.
  2. Battery Type – Here you pick from the drop-down menu whether you are using AGM or lithium batteries.

It is worth repeating that it’s important to correctly size your battery bank before using our solar calculator. If you haven’t done so already, we provide a link in the document for you to click to download the battery spreadsheet.

4. Identify Minimum Recommended Solar Size

Once you have entered the information in Step 1, the solar calculator will determine, under Step 2, the MINIMUM solar wattage size that is appropriate for your van. If you haven’t completed the first step, there will be no value here.

Refer to the red box below, which outlines Step 2.

Essentially, solar calculator derives the minimum wattage recommendation based on the below information.

  • If using lithium batteries: Recommended solar watts is a 1:1 ratio to Ah battery bank.
  • If using AGM batteries: Recommended solar watts is a 1:2 ratio of Ah battery bank.

5. Finalize Your Own Solar Array Wattage Size

Next, based on the minimum wattage recommendation from Step 2, you will need to decide, in Step 3, how much solar you will actually install on your camper van. This is entirely up to you. However, we strongly recommend that you choose a total wattage that is equal to, or greater than, the minimum recommendation.

Refer to the red box below, which outlines Step 3.

To make the process easier, we recommend choosing a total solar wattage that is a multiple of 100, 160, 180, or 200. This is because these four sizes are the most widely available solar panels sizes on the market.

Lastly, it is perfectly OK to install more than the recommended minimum. A larger solar array means your batteries will recharge faster, which can be beneficial when parked for extended periods of time in shaded areas.

For more: Unbound Solar has a short, informative post on the effects of shade on solar panels.

Example: For our van, our minimum solar size was 300W. But we decided to install more and went with 360W of solar instead. This was 20% larger than the recommended minimum.

6. Decide Number Of Solar Panels

In Step 4, you must enter how many solar panels you plan to install on your camper van. This is why, in Step 3, we recommend finalizing a solar array wattage that is a multiple of 100, 160, 180, or 200.

Refer to the red box below, which outlines Step 4.

Tip: Go for fewer but larger panels, if possible. And if possible, keep the total number of solar panels to not more than two. This will help to keep your wire size small and eliminate your need for solar in-line fuses.

Example: For our van, since we chose to install 360W of solar we decided to go with two 180W solar panels.

7. Choose & Buy Solar Panels

Now that you know the amount of solar watts you will install AND how many solar panels you’ll have you are ready to purchase your panels.

In Step 5 we give our four recommended panels. All our recommended panels are manufactured with the newest ‘9BB’ technology, meaning that these are the panels with the highest efficiency when converting sunlight to power.

Refer to the red box below, which outlines Step 5.

Below we also list each of the four panels that we recommend in the solar calculator spreadsheet.

Though you might be ready to celebrate at this point the solar calculator isn’t done yet!

This powerful calculator can also help you identify all the correctly sized parts and components you’ll need to complete your DIY solar project. Keep going below to see how this works.

8. Enter Solar Panel Imp(A) and Max Series Fuse Rating

In Step 6 you will see two green-shaded boxes. Here you will need to enter the “Imp(A)” and “Maximum Series Fuse Rating” of only one of your solar panels. You can easily find this information on the backside of the solar panel or if you view the panel’s only sales page.

Refer to the red box below, which outlines Step 6.

Every single solar panel on the market today has slightly different information. So you need to know the information of your exact panels.

If you bought one of our four recommended panels, we include the Imp(A) and Max Series Fuse Rating information in the Blue-shaded box to the right, which is titled “Step 6 Recommendation”.

Otherwise, you can find your panel’s technical information sticker, which should look similar to the image below.

9. Decide Series Or Parallel Solar Panel Wiring

In Part 7, the last piece of information you need to decide is, if you have more than one solar panel, how you will be wiring the panels together. You can wiring the panels together either in series or in parallel. If you are unsure, check out our series vs. parallel post to learn more.

If you only have one solar panel, select “Series”.

Refer to the red box below, which outlines Step 7.

Tip: If you have only two solar panels to connect, select “Parallel”. If you have three or more panels, select “Series”. This is because although parallel wiring is more beneficial, it because much more complicated and risky (higher amperage) to do parallel wiring with 3+ panels.

10. View Calculator Summary Table

This is the best part of the camper van solar calculator.

Once you have filled out all the green-shaded cells, the summary table at the bottom will help you to select all the tiny parts and components that you’ll need to complete the solar wiring project. This includes:

  • Fuses & circuit breakers
  • Wires
  • Charge Controllers
  • Branch connectors

All recommended products will be appropriately sized for your unique solar system.

Refer to the red box below.

In the “Parts Size” column, you can click each of the individual products to purchase them on Amazon.

Good To Know! All solar sizing calculations are in line with National Electric Code (NEC) guidelines.

11. Download Solar Wiring eBook

Lastly, each item listed in the summary table has a part #. To make use of these part numbers, download our solar wiring eBook. The eBook has informative solar wiring diagrams.

The part numbers in this table correspond to the part numbers in the wiring diagrams so that you can see where each part needs to be installed so that you can complete your solar project.

Refer to the red boxes and arrows below.

Every solar component in the calculator summary table has a “Part #”, listed in Column D. For example, the solar charge controller is part #16.

To identify where to install each component, download our solar wiring eBook and locate each product number in the solar wiring diagrams.

Cover page of solar wiring diagrams PDF

Interested In The MOST Efficient (9BB) Solar Panels?

“9BB” solar panels are becoming the next big thing in the solar panel industry. Read our 9BB solar panel post to learn why these panels are more efficient AND have a longer usable life than traditional solar panels.

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BougeRV 14% discount banner (square)

Was This Solar Article Helpful? We have other posts dedicated to help you install your van life solar system. Check out our Camper Van Solar Installation Guide to read more great RV solar content!

Final Thoughts: Calculating How Much Solar You Need Is Just The Beginning

Figuring out how much solar power your campervan needs is an important first step to building your campervan solar system. But it’s just that, the first step.

If you found this article helpful, check out our DIY solar system build series, where we teach you how to construct your own camper van solar system from scratch.

Questions? Comments?

And if you have any questions or comments, please let us know in the comments section below.

Happy building!

Solar Calculator

This van life solar calculator is divided into three simple steps.

  • Step 1: Calculate Battery Size
  • Step 2: Calculate Solar Wattage Size
  • Step 3: Calculate Size Of Solar Components

Step 1: Calculate Battery Bank Size

Fill out the simple form below to get a recommendation on your ideal battery bank size. This is a simplified form for those that do not want to do detailed calculations. For those that want to be as accurate as possible, download our worksheet from our battery calculator post.

Battery Size Calculator
  • Very Low: Only the basics. One laptop, one smartphone, a few LED lights, and a vent fan.
  • Low: A couple laptops and smartphones, 12V fridge, vent fan, water pump, 6-10 LED lights, and small appliances, like a blender.
  • Medium: Everything from "Low", but add a diesel heater and occasional use of a hairdryer, coffee machine, electric kettle, and Instant Pot.
  • High: Everything from "Medium", but add more constant use of 110V/220V appliances and some use of an induction stove.
  • Very High: Everything from "High", but add a hot water heater, some use of an air-conditioner, and more frequent use of an induction stove.

Step 2: Calculate Solar Wattage Size

Next, enter the recommended battery bank size (Ah) and type into the fields below. The form will then calculate the recommended minimum solar array wattage size.

Solar Wattage Size Calculator

*Get this information from the calculation in Step 1.

Minimum Solar Wattage Size

This is the minimum you will need to sufficiently recharge your batteries each day. You can always install more solar than this recommended minimum.


Step 3: Select Solar Panels

Solar Size Post (Select Solar Panels)

* Enter your desired solar wattage size that is equal to, or greater than, the recommended solar size in Step 2. Preferably, the wattage is a multiple of 100, 160, 180, or 200.

* This is the number of panels you will install. For example, if you plan to install 200W, you can use two 100W panels OR one 200W panel (less panels is better).

* You will need to finalize your exact solar panels before moving on to the next step.

All solar panels recommended below are manufactured with the latest '9BB' technology for the highest conversion efficiency. Select your panels based on the information you entered above. Don't mix panels of different sizes. Personally, we are impressed with BougeRV's quick and helpful customer service.

Step 4: Calculate Solar Charge Controller (& Components)

Solar Size Post (Charge Controller & Components Sizing)

* Note:
This is the number of panels in your array, which you already decided in Step 3. Enter it again, in this field.


* You can find the information for 1 & 2 either from the technical sticker on the backside of your panel or on the panel's online product info page. We also list this information for the four solar panels we recommended in Step 3.


If you have two panels, we recommend to wire in parallel. If three, or more, we recommend to wire in series.

Your Solar System Overview

Recommended Components

Thank You For Reading!

We’re Yuko and Eric! We both grew up in Asia ( Japan & Hong Kong ), we left our jobs and homes in 2018 and started traveling full time from Canada to Argentina in our self-converted camper van since end of May 2019. “Asobo” means “Let’s play” in Japanese. We named our site “Asobolife” because the life is always uncertain and we live only once so it’s important to always keep positive, playful mind and enjoy the moment you are in the present. We also want to use this website to share our road trip and van building experiences to inspire our readers. We hope you enjoy!

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