How to Design and Install Solar on a Camper Van

DIY Campervan solar

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New here? Welcome! This blog post houses all of our DIY solar and electrical tutorials for campers, vans, truck campers, and RVs.

Been here before? Welcome back. The page has a new look. There was SO much information here it was getting messy, so the topics have been broken up into individual topics so they are easier to find and gives a better user experience.

Our interactive solar wiring diagrams have been a real hit, but most of you want to know more about the ‘why’ behind the interactive diagrams. Perhaps you’re building something completely off the wall and are looking for some more, general learning about solar and mobile solar systems. You’re in the right place!

Keep reading to see our step-by-step guide for how to install a mobile solar and electrical system in a camper, van, truck camper, or RV.

DIY Camper Solar System Guide

This DIY Camper Solar System Guide is a multi step, complete educational series that by the end, you will know what all of the parts of a solar system do, how they work together, what you'll need for YOUR specific system, and what to expect during the build. These lessons go in order so I recommend starting from the top.

77 thoughts on “How to Design and Install Solar on a Camper Van”

  1. Very well put-together and comprehensive lists here. Excellent work! One suggestion would be to add one more column that includes a short description for what the item is for, e.g. in the case of the wiring, where there are different wires sizes/types, it would be helpful to know where to use the different sizes/types of wire.

    1. Hey David! Thanks for the feedback. You caught me working frantically in the middle of a post update and all of that will be coming soon! 😀

  2. Hey Nate, this is such great information and instruction! That 350 amp ANL fuse? I’ve seen that between the battery switch and the pos. bus, and also between the pos. bus and the inverter. What is the correct location? Again, you guys do an incredible job!

    1. Thanks so much! That will go between the busbar and the inverter.

      If you felt it necessary to protect the wire going between the battery and busbar, you could also put a second one there if you so desired.

  3. Thanks for all the work you guys have done putting this site and the fb DIY group and maintaining them. I was able to retire early and travel in the SW for climbing and hiking for 4 months each winter. I’m building out my 2016 MB 170 and am ready to hit some buy buttons for the rest of the materials. Following your guide I plan on 360W solar feeding 1 of the Battle Born batteries(possibly expanding to 2 later). I have no need for 2000w of A/C from an inverter. We are fine with 12VDC for our needs but…I would like to have 1) a dc-dc charger 25amps or so to charge the house battery while driving and 2) an AC battery charger 40ams or so to charge overnight at a KOA or friend’s driveway in case of an extended no solar condition. It looks like a normal wet cell or AGM cell charger will work with the BB battery management system. Is that true ? Any recommendations for products I should look at ? Thanks much and happy travels ! Bruce

    1. Hey Bruce! Thanks, and it sounds like you’ve making the most of our time. We LOVE that area of Utah. Where is your favorite?

      Anyway, for charging from the alternator, you’ll be looking for the Sterling chargers. They come in quite a few sizes. Here is a 40A (https://amzn.to/2RFptyI) but you can go from there.

      For a single battery, you’ll need to stay below 50 amp hours charging.

      BUT… if you want make the jump to 2 batteries, you can use the less expensive Li-Bim from Battle Borm (https://battlebornbatteries.com/shop/lifepo4-battery-isolation-manager/?afmc=explorist_bb67)

      It’s also included in this kit: https://battlebornbatteries.com/shop/adventure-in-a-backpack-lithium-battery-kit-200ah-amp/?afmc=explorist_bb67

      For shore power, if you don’t want the inverter, you’ll be looking at this: https://amzn.to/2A44LC9

  4. Hey Nate

    Thanks for this, I’m trying to learn this stuff and this has been a great help. I’ve got a few questions but this one is the one I’m least sure of at the moment.

    I’m looking at the 700 Watt Solar Kit. You’ve got 4 x 175W 12V panels connected in series. While they wouldn’t actually output exactly 48V I assume the MPPT would generally autodetect them at 48V.

    “The Smartsolar 150/85 is a great choice for controlling up to… 48V at 4800 watts”. So we’ve got a tonne of overhead on the input of the MPPT, it can handle way more than 700W coming in at 48V.

    So my guess for the heftier MPPT is because you’ve got all the battery suggestions in parallel, maintaining at 12V, because the MPPT can only handle 85A out which means 1,020W. Technically the 150/70 (840W out at 12V) would do the job but overhead is good.

    However you also suggest the 150/85 for the 875W and 1050W options. So considerably less overhead for 875W and have underspeced for the 1050W panels.

    The solution would seem to be to get a 24V battery system (either through different batteries or through putting them in series) and a 150/35 for the 700W, a 150/45 for the 875W and a 150/60 for the 1050W.

    Of course then you’d have to get a 24V inverter and make sure anything running directly off of the DC was 24V or get a step down converter for 12V stuff. Which complicates things.

    So I guess to keep it uncomplicated I’m suggesting you change the 1050 Watt Solar Kit MPPT to the 150/100 one?

    I’m working this out as I go along and have no idea if this is gibberish. But it’s been helpful to me to try and nut that out. It’ll be helpful if I’m completely wrong and someone tells me why too.

    1. “Thanks for this, I’m trying to learn this stuff and this has been a great help. I’ve got a few questions but this one is the one I’m least sure of at the moment.

      I’m looking at the 700 Watt Solar Kit. You’ve got 4 x 175W 12V panels connected in series. While they wouldn’t actually output exactly 48V I assume the MPPT would generally autodetect them at 48V.”

      Here is the first spot your math is off. Those panels put out 19.06 panels each at max power output, so 4 of those panels in series would be about 76 amps coming into the controller which the controller would then regulate down to the 13-14.4v necessary to charge a battery.

      ““The Smartsolar 150/85 is a great choice for controlling up to… 48V at 4800 watts”. “

      That “48v” number would be for a 48v battery bank… not 48v of solar panels

      “So we’ve got a tonne of overhead on the input of the MPPT, it can handle way more than 700W coming in at 48V.”

      Indeed a bit of overhead (but not as much as you think since you were looking at that 4800w number (which is for a 48v battery bank)). The Victron 150|60 (https://amzn.to/2pNl93P) would be a better choice for 700w on a 12v battery bank.

      I likely chose the 150/85 because at the time of making the kit parts lists, the 150/60 was out of stock

      “So my guess for the heftier MPPT is because you’ve got all the battery suggestions in parallel, maintaining at 12V, because the MPPT can only handle 85A out which means 1,020W. Technically the 150/70 (840W out at 12V) would do the job but overhead is good.

      However you also suggest the 150/85 for the 875W and 1050W options. So considerably less overhead for 875W and have underspeced for the 1050W panels.”

      Apparently victron has added new controllers to their amazon store since I made these kits (only like two weekes ago… sheesh…) I’ll update the lists, but for 875w kit, go with at least the 150/70 (https://amzn.to/2ITymkm). All other parts on the list would remain the same.

      The 150/85 isn’t underspeced for the 1050w kit. See below…

      “The solution would seem to be to get a 24V battery system (either through different batteries or through putting them in series) and a 150/35 for the 700W, a 150/45 for the 875W and a 150/60 for the 1050W.

      Of course then you’d have to get a 24V inverter and make sure anything running directly off of the DC was 24V or get a step down converter for 12V stuff. Which complicates things.”

      Every single thing on this blog post is about 12v systems. Adding 24 or 48v systems into the mix just makes this already complicated blog post even more confusing, so I’m not even going to address 24 or 48v systems in this reply.

      “So I guess to keep it uncomplicated I’m suggesting you change the 1050 Watt Solar Kit MPPT to the 150/100 one?”

      The 1050 watt kit will be 114v (19.06×6) & 9.21 (1050/114) amps input (into the controller) which the controller would regulate down to the 14.4v that your lithium batteries will charge at, which is an output amperage of 72.91 amps out.

      Feel free to size the controller bigger if you like, but the 150/85 is still in spec for 6×175 watt panels.

      “I’m working this out as I go along and have no idea if this is gibberish. But it’s been helpful to me to try and nut that out. It’ll be helpful if I’m completely wrong and someone tells me why too.”

      Hopefully my replies helped. I think my biggest takeaway for you is to ignore 24v and 48v battery bank systems. They have their pro’s, but at a basic level, 12v systems are easier to design. Also, the next biggest takeaway is ‘There is no such thing as a 12v panel’. Most ’12v panels’ are really closer to 20v and with a properly sized mppt controller, the voltages of the individual panel doesn’t matter so much (unless you are doing math, then you have to go by what it says on the label.)

      1. Hmm. I parsed that quote down to just the 4800W bit but it does actually say “of solar panels”:

        > The Smartsolar 150/85 is a great choice for controlling up to 1200 watts of solar panels at 12V, 2400 watts at 24V, or 48V at 4800 watts.

        1. 1200 watts of solar panels if you have a 12v battery bank. 2400 watts of solar panels if you have a 24v battery bank. 4800 watts of solar panels if you have a 48v battery bank.

  5. im looking to power my 30amp camper with solar, which is better solar or wind? Both? Need help determining how to do this and how much equipment I will need. Im a year around camper and want to move to some property I bought and not have to pay the electric company. So that being said I need enough power for the summer and winter, ie. AC and Heater

    1. Hey Scott! I haven’t seen anybody who is happily and successfully powering much of anything on an RV with wind power. So, take that for what it’s worth. You’re going to need to size your system by your power consumption and your budget. AC is a power hog, but is possible with the right $$$$$. Have you performed the power audit yet? What kind of budget are you working with?

  6. Nate and Steph, awesome job and thanks for all your hard work you two put into your blog and videos to bring us free content. Thanks for not only sharing content that’s right/correct but also for showing us what went wrong and how you fixed it. Most people wouldn’t share this info (mistakes). Great job and love your van.

  7. hi, question about your theory of 4 x 100w solar panels in series ? wouldnt the usual ohms law apply to solar panels as it does to say batteries, where you series battery and increase the voltage but retain the current/amperage capabilities ? if so wouldnt the 4x100w panels provide you 75-80 volts (4 panel combined voltages) but only 5 amps capability ? i understand all the battery and ohms law rules but something i’m missing on the solar panel and controller side of things as you state high current capability after MPPT controller.
    I may be way off and appreciate some guidance there 🙂
    and what advantage or disadvantage would there be if you series PAIRS of solar panels and then paralleled the pairs (2 x 2 panels) paralleled to (2 x 2 x panels), would that give you greater capacity to charge the house battery, theory being more amps (parallel pairs) ??

    1. hi, question about your theory of 4 x 100w solar panels in series ? wouldnt the usual ohms law apply to solar panels as it does to say batteries, where you series battery and increase the voltage but retain the current/amperage capabilities ? if so wouldnt the 4x100w panels provide you 75-80 volts (4 panel combined voltages) but only 5 amps capability ? i understand all the battery and ohms law rules but something i’m missing on the solar panel and controller side of things as you state high current capability after MPPT controller.
      I may be way off and appreciate some guidance there ?

      Yeah, that’s kind of confusing and you’ve got it…halfway… 5 amps at 80 volts (5 amps * 80 volts = 400 watts) coming into the charge controller would convert over to (400 watts / 14v (charging voltage) = 28 amps into the battery. If you want visuals of this, it’s in this section: https://www.explorist.life/diy-campervan-solar/#charge-controller

      and what advantage or disadvantage would there be if you series PAIRS of solar panels and then paralleled the pairs (2 x 2 panels) paralleled to (2 x 2 x panels), would that give you greater capacity to charge the house battery, theory being more amps (parallel pairs) ??

      There would basically be no advantage to doing it like that.

  8. Hi – On the 525 Watt system which circuit breaking is coming from the solar and which is coming from the controller??? Excellent video and information on the blog – Thanks

  9. solar panels in series suffer from one condition. If any panel is partly blocked the efficiency of the solar setup drops to the level of the least efficient panel in the setup.

    for a parallel setup this is not the case. However a parallel setup has a different set of issues: more current which requires thicker wires (or smaller wire gauge size) and larger current for MPPT controller to handle.

    Some people therefore choose to use a series-parallel combo.

    any thoughts ?

    1. There are hundreds of thousands of ways to design a solar setup. If I catered this blog post to every single possibility, it would become less and less helpful. What you are suggesting is indeed a way to wire solar panels, but it does complicate the system slightly. Most of the people I have talked to in real-world scenarios (Steph and I included) have not had issues due to partial shading. Either we are in the shade or in the sun. There is rarely the awkward middle ground. If there IS an awkward middle ground, we will pull forward 5 feet or back up 5 feet until the problem is solved.

      That’s why I make all of the wiring diagrams at the bottom of this post; panels in series.

      Now…if this were for a tiny house or something more stationary and you had partial shading that happened every single day, that’s where I could see altering the wiring diagram.

  10. Nate, I have a couple of specific questions about my DIY design for me Sprinter electrical system. Is this “Comment” section away for us to communicate or is there a better way?

  11. Hello. I have a 1988 RV and wanting to put solor on it. I have brought the kit but not understanding how to link everything together. I understand how to meet up the solor to the inverter and to the house battery through the controller and how to hook up the main battery to the controller. Where I’m confused is how do i set up the old setup to the new one. I have a generator involved.

    Any assistance is greatly appreciated
    Thank you LaVerne

    1. Hey Laverne! The best way for me to help out on this would be for you to draw a wiring diagram as accurately as possible as to what you’ve got going on so I can make a recommendation.

  12. Thank you both so much for this extensive explanation, together with the youtube. Would this set-up work the same way for 240V….?

      1. Hi Nate,
        I was wondering the same thing. Can you explain real quick about what exactly is the difference between the 110v and the 240v. Thank in advance!
        You rock!

  13. Great guide guys. I am in the early stages of planning a van build and your info will be invaluable in the final design stage.
    Thank you so much for putting it together and making it available.

  14. I am in the planning stages of my solar system for my bus. I ordered 10-245w panels and I’m being told that will be too much. I understand the biggest expense in the system is going to be the battery bank. How will I know my daily usage without first purchasing all the appliances. The solar is basically the first thing that needs completing before moving forward with the build. Is there ballpark number out there that the average RV uses during a day and can be used to ballpark needs?

    1. That’s a HUGE system for sure, but I will never say something is TOO big. You’ll be in the “I can run an air conditioner off of solar” realm with that setup depending on battery bank.

      There’s really no ballpark number as everybody has drastically different needs.

      The best way is to perform a power audit. We have a calculator and tutorial that’s currently housed here: https://www.explorist.life/diy-campervan-solar/#how-to-perform-a-solar-power-audit

  15. Thank you for helpful post.
    A charge controller is especially important when wiring your solar panels in series due to the fact that the voltage is added up. A charge controller is able to accept a higher voltage and in-turn converts this to the correct voltage of your leisure battery.

  16. Literally just started learning this stuff about 10 minutes ago, when i clicked the link to this article! hahhaa many questions to come, but for now I am just trying to wrap my head around the start. We are getting our roof rack from Aluminess pretty soon and want to run wiring for Solar, potentially lights before we get the rack. We know what panels we are getting, so I guess I am asking did you guys cut your entry gland, set up your wires, MC4 connectors and everything – then have your rack installed then mount and hook up the panels? Thanks a bunch in advance!

    1. We cut the hole and mounted the entry gland first then mounted the rack over the top of it then ran the wires and hooked up the panels.

  17. Hi Nate, thank you for your post!

    Are you concerned about overstressing your sprinter’s stock alternator by having it charge your lithium batteries? Have you had any issue with this?

    1. I’m not really ‘concerned’ with it, but I really only charge via the alternator when necessary. I typically have the isolator disconnected until needed and let the solar take care of the job.

  18. I recently started research on my first van conversion.

    This is the first site that I find to be truly helpful, thank you.

    That being said first impressions are important and the first part of the second sentence of this page “This guide will take you not only our solar builds, but” seams to be missing a word.

    Regarding “Charge Controller SEC. 2” after the list of 14 Victron controllers, and under the sub title “WHAT DO THESE NUMBERS MEAN?!?” The 2 words in blue “charge controller” as I understand it should actually read “solar panels”.

    Sorry to point these things out but my OCD compels me.

    Lastly, from my perspective (novice) the pictures in your diagrams look nice but it would helpful identifying the parts if they had basic labels such as bus bar, isolator, Fuses, etc.

    Thanks again, excellent site.

  19. I have a camper in a seasonal spot at a camp ground I am only there on the week end . My ? is can I leave the panels on charging the battery all week without over charging the battery ? I do have a mppt controller .

    1. I can’t speak for all MPPT controllers, but most name brand controllers including Victron controllers will have no problem with your proposed scenario.

  20. Nate, I plugged in my numbers with the excel sheet that you have on the webpage about figuring out how much solar you need. My total amp hours per day come out to about 1700(mainly because of air conditioner). In your description, it says multiply this number by 3 for minimum? I feel like there is no way to get big enough battery bank for this setup. Any advice would be great! Thanks

    1. Hey Jacob! x3 on a 1700Ah bank would indeed be…dare I say, excessive? I looked back over my blog posts and spreadsheet and although I remember writing that at one point, I must have realized it was confusing because after a recent revamp of our content, I can no longer find that figure. The updated wording is a little more vague, but doesn’t make it seem like x3 is a rule or something (because that’s not how I meant for that to come across. The current wording is: “The numbers you see are just general recommendations. Want to spend more time in cloudy environments? Maybe you should consider sizing up a bit. Budget can’t handle your recommended components? Perhaps size down (but PLAN for expansion). These are all just general recommendations that I feel confident in recommending. Any more is better. Any less is on you.”

      Source: https://www.explorist.life/what-size-of-solar-system-is-needed-to-power-a-camper/

  21. Hi Nate: I have been following you and Steph for your entire build as I have thought about starting my own build. I now have a 2017 Sprinter and I am enjoying the build process. Working on retiring in a couple years and plan to travel and hike, not planning on parking in one spot more that a day or 2. I have done your Power and came up with an estimated daily use of 400 Amp hours per day. didn’t want propane and will be using a Induction stove and Rixen’s diesel heat and hot water.
    What would be your recommendation?

  22. Hey guys, just found your blogs and YT. Definitely going to be liking and subscribing.

    Question, it looks like you’ve got your fan under a solar panel, how does that work and how’d you do it please?

    1. Welcome aboard! The roof rack is simply high enough that the roof vent has clearance to fully open without hitting the solar panels.

  23. WOW! You guys are a lifesaver. We are in process of building a camper van, not to live in, but to certainly go on the road for a month or two at a time. I am not fearful of any of the systems we want to put in except for the power system and solar. The above diagram is brilliant! Gives me the basic knowledge to charge our batteries from shore, solar, or the chassis as well as having some dedicated shore power options bypassing the batteries. I will be using this as my “bible” as I move forward. Thank you x10!

    1. I have one question. Why use a Lithium Battery Isolation Manager and not use a VSR between the car battery and the bus bar?

      1. The lithium battery isolation manager is basically a VSR, but with different open/close parameters that make it more conducive for charging lithium. There will be a follow-up, more in depth blog post talking about this coming up soon, so be sure you’re subscribed to the email list.

    1. The ebook is no longer available. Fortunately, all of the information (and a ton more) can be found right here on the page you are looking at.

  24. Hello and thanks for the great blog. I’ve been thinking and no one has ever brought it up to my knowledge but… why not double the solar panels to give a higher charge rate on less than perfect days

  25. Hi Nate,

    Why the 15 amp breaker on the “AC out” from the inverter and not a 30 amp breaker with 10/2 romex?

    I’m doing a install in my 30 amp RV and think I may use a 30 amp breaker instead with 10/2 romex… Just curious why you limited the AC system 15 amps?..

  26. Hi, love this post and have lived by it religiously as we do our solar install. We have a 525w solar setup with 300ah in Lithium BattleBorn batteries. In your experience is it necessary to vent the batteries? Thanks!

  27. You have saved me some struggle. I appreciate it and certainly will be using your affiliate links.

    One question: I cannot find anything in your post about “Grounding”. Maybe I missed it, can you point me to the right place?

    Thank you

  28. Peace…what’s the difference between -12volts system and a +12volts system…and is that a concern with solar power to RV use ?

    1. I’ve never heard of anybody differentiating between the two. If those are positive ground 12v system vs negative ground 12v system; I only use negative ground 12v systems.

  29. Thanks for taking the time to share this information. I’m rebuilding an Airstream and much of the electrical information is relevant.

    FYI, for some reason I have not been able to sign up for the e-book. When I click to your site the page freezes and that’s as far as I can get.

  30. My camper is stationary (used as a permanent camp) and off grid. I am looking at getting Solar and all of the installs suggest connecting to the existing wiring inside the camper. Is there any reason I cannot simply connect the solar to batteries outside the camper, and connect the Shoreline to the inverter? Seems to me that this would not only run the A.C. type accessories but would also charge the batteries inside the trailer. Is there any down side to this approach?

      1. Not sure what you mean by “Clean” install. Is it less efficient (other than the fact I have additional batteries)?

  31. Nicholas Brokenshire

    Do you have a start up procedure you can recommend for the first time you plug everything in. I have followed your diagram for the 200 AH 350 watt recomdation.
    Thanks for all your instructions.

  32. hi Iv just found your site with a lot of great info. I ve been looking to try and sort out a queston that has been worrying/nagging me.
    I have installed solar panels directly to the roof of my van. They have been installed using metal brackets with no insulation between the frame work of the panels and the van. eg the grounding of the panels is directly connected to the chassis of the vehicle and therefore connected to the starter battery.
    My question is should my house batteries (negative) also be connected to the chassis to complete the circuit and would this have any effect on the vehicle electrics? Thanks for your time Darrun

    1. As long as there is a dedicated negative wire from the solar panel to the charge controller you should be fine. But I do recommend making a battery to chassis connection in any regard.

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