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200 Watt Solar Panel Wiring Diagram

This 200W solar panel wiring diagram for RV and campervan conversions is useful when planing your build. It lays out each component of the electrical system and details all the main components.

Read our electrical page for detailed information on each part.

200 Watts is enough to power small electronics such as cell phones, lights, and vent fan as well as a couple of larger items such as laptops and a refrigerator. Keep in mind that if you plan on wiring in an alternator or generator the system layout changes a bit. It’s better to plan for them at the beginning than try to add them in later.

Before purchasing wires and fuses, read our post on wiring your campervan.

The diagram below depicts a system with <10ft. of wire. If you need to run your wires longer, refer to the graph in our wiring your campervan post to determine the correct wire gage for you.

Want a different amount of solar?
100 Watt Solar Panel Wiring Diagram  •  450+ Watt Solar Panel Wiring Diagram

Electricity is a serious task to take on. There are many examples of things online that “can” be done but should not, so consume Youtube instructions and articles such as this one with caution. It is always a good idea to consult with experts before you buy expensive parts to make sure the way you are planning on using it will be safe.

200W Solar Installation Parts*SizeQuantity
Polycrystalline Solar Panel100 Watt2
Solar Panel Roof Mounting Z-Rack-Optional (2)
Solar Panel Adjustable Tilt Mount-Optional (2)
MPPT Charge Controller20A1
AGM Deep Cycle Battery150AH1
Pure Sine Inverter400W1
10 Way Fuse Block-1
Bus Bar-1
Battery Terminal Connectors-1
Chassis Ground Wire2AWG1
Electrical Wire Crimp Connector Assortment Kit-1
Ring Terminals8AWG1

*Not included are the wiring and small fuses needed as those vary between installs and can be bought at a hardware store.

Total Cost of a DIY 200 Watt Solar Panel Kit:

When choosing to buy just the basics, you can expect to spend about $800 on a 200 Watt solar kit including everything except the wires themselves (this can vary depending on how much wire and how many devices you’re using).

If you want to save some time, Renogy offers a partial solar kit with MPPT controller. Renogy pricing is usually quite good for the convenience that it offers if they have a kit that matches your needs.

You can also buy a solar suitcase with charge controller. This is portable and would not attach to the roof. With this suitcase you would need to purchase an inverter, fuse block and batteries.

Alternatively, a Goal Zero Yeti kit can be purchased and includes everything except the solar panel mounting hardware. This would be the equivalent of a 100Watt solar suitcase paired with a 100Ah AGM battery and 1200 Watt inverter. Our estimate that the DIY pieces separately for this would be easily under $1000.

Solar Power Kit Parts

Solar Panels

Polycrystalline and monocrystalline solar panels are the best for an RV or camper. Monocrystalline panels will have a slightly smaller footprint, but polycrystalline are generally the least expensive.

Rigid solar panels are more durable than flexible ones and they also last longer.

For the simplest set up, wire your solar panels in series as shown above. The exception to the rule is if you are using a PWM charge controller.

wiring solar panels in series vs parallelAn extension cable and is necessary to connect most solar panels to your charge controller. Solar panels tend to come with short cables.

More Info: Best Solar Panels

Mounting Brackets

Z-brackets are the easiest way to mount solar panels to your roof.

An adjustable tilt mount will enable you to adjust panels so they are directly facing the sun. Tilt mounts can increase your solar panel efficiency by as much as 30%.

Charge Controllers

There are two types of charge controllers, PWM and MPPT. A charge controller helps get solar energy into your battery. In a 200 Watt solar panel system, a 20A MPPT charge controller is a good choice.

More Info: Charge Controllers


For 200W of solar power there are a few different battery options to choose from:

A single battery will be the easiest to install. Deep cycle batteries can be discharged up to 50% capacity, while a lithium battery can be discharged up to 90% capacity.

A lithium battery is more expensive than a deep cycle battery. Two 6V batteries are smaller and easier to move.

Battery terminal connectors are use to bond your battery to the other wires.

More Info: Batteries


The pure sine wave inverter is an optional component. An inverter converts 12V DC electricity into 120V power. You can use an inverter to plug in household items like a laptop or TV.

We recommend up to600W inverter for a 150Ah deep cycle battery or up to a 1000W inverter for a 100Ah Lithium battery.

If your inverter takes more than our recommended power out of your batteries on a frequent basis, the batteries will wear out quickly.

More Info: Inverters

Wires and Fuses

The wire and fuse sizes are dependent on how far you are running your wires. The diagram depicted above shows approximate gage and fuse sizes for running under 10 feet of wire.

If you are in a large RV and running the wires longer, refer to our wiring guide to determine the appropriate sizes.

The fuse block with bus bar, and wire crimp connectors are needed to use your batteries.  

More Info: Wiring & Fuses

This Post Has 26 Comments
  1. This is very well done. Thanks.

    We camp out of the back of our pickup/topper. How would you add charging off the trucks alternator while driving?

    Also, we are looking at an induction hob which draws up to 1800 watts or a mr. coffee at abou 900 Watts. Neither will run more than 10 minutes per day. Can you give me any advise on sizing batteries and inverter. I don’t understand max continuous amps either. It sounds like something to worry about.


    1. Hi Paul!

      Connecting the alternator is pretty easy and there are several ways to do it. We have a large relay connecting ours ( It can be wired to a switch that is connected to your accessory wire so it is able to turn on when the accessory wire is on (you want it off when the truck is off so it doesn’t drain accidentally and so the house batteries aren’t trying to balance against the chassis battery when it’s off). Use a 2 or 4 AWG wire and just run it from the chassis battery to the house battery. The alternator will adjust the voltage load automatically and the charge controller will also adjust so no need for any other switches.

      Another thing you can do is add a manual switch. This is the least likely to break, but it requires that you remember to turn it off to make sure you don’t drain your chassis battery or have weird balancing issues. Something like this:

      Both of those options have the added bonus that if your chassis battery gets drained for some reason, you can get extra juice from your house batteries to start the truck.

      The last way is with an isolator such as this one: This is the simplest to wire as it automatically detects when the alternator is on and when the chassis battery is fully charged it then connects the batteries so the house batteries can charge as well. There is a little voltage drop with these so these aren’t quite as efficient but it’s not significant.

    2. As far as cooking and coffee: Our base recommendation is to look into fuel-based solutions for cooking, especially in smaller builds. Induction cook tops are efficient compared to other electrical sources, but in general electricity is inefficient for heating. On full power, a 1800W induction cooktop is drawing 150amps from a 12V battery. Even at 10 minutes, that 24Ah. Add a 900W coffee that’s on for 10 minutes and you have 36Ah of electrical usage total just for coffee and soup. For sizing, to keep your batteries healthy you need to look at the data sheet.

      I’m not familiar enough to give you a good answer on the healthy discharge rate of a battery. In the past, I have used the “1 hour rate” as a baseline for the max amount of power I’m comfortable with pulling at once. With this battery, it would be 122amps:

      If you have looked at that and still want to use electricity, then I would recommend in general at least 200Ah battery for a healthy discharge rate and a 2000W inverter. But like I said, I will need a bit more research to be confident in that answer.

  2. Ian, Thanks for the response. I don’t see the difference between option #1 and #3 for the isolator. Both look to be relays with 12v switch which should be connected to a circuit that is HOT when engine is running. I have looked at Blue Sea automatic charging relays which look like the isolate the starting battery from the house based on voltage. It looks like diodes are included to prevent house batteries draining toward the starting battery.

    The isolator relay seems easy. Do you have a fuse/circuit breaker between the battery and the relay?
    the batteries can charge at 100A but like to charge at 50A. So, I am a bit confused on a safe way to charge from the alternator.

    I understand and agree with your input on the coffee maker and induction. I will clarify with the battery supplier. I believe two batteries in parallel with 100amp continuous will provide the needed power. Then its just a question on how long you run at that level of draw and how long it will take to charge from solar.

    We are camping in the Leer canopy with limited room. We call the driver and passenger seats of our F350 the “living room”. When its wet out it would be nice to make coffee inside. Space is tight so the open flames from the camp stove are a bit scary. I understand its the most effective way to heat/cook. Just hoping for a simple safe solution. On the other hand, if we only use the batteries for Cell/internet and charging our electronics we would need a much smaller battery battery and solar.

    Thanks for your help.

    1. Paul:

      #1 and #3 are nearly identical options but I wire them slightly different. With the isolator, I don’t put an in-cab switch because the isolator already protects the chassis battery from being drained or have weird balancing issues by the house electrical system (with the diodes you mentioned). With the relay, I put an in-cab electrical switch so that if for some reason my house batteries are not working properly I can disconnect them. It’s kind of a redundant safety that I don’t think the isolator needs. Both options are still wired so that the house battery is disconnected when the engine is off.

      For fuses: I’d use two fuses/breakers depending on the length of your charging cable. One between the chassis battery and the relay/switch/isolator like you said and one right next to the house battery. The reason is that this wire can be always hot, so even if one fuse blows the wire can still be shorted from the house batteries. This would come into play if the short was from a chaffing charging wire. But I’m kind of a hypocrite; we just have one at our house battery end next to the batteries.

      For the “safe charging” subject: I have to put a heavy emphasis on me not being a professional. I’ve pieced together my knowledge from various forums but don’t have much backup. Your alternator (even if it’s a 150A one) is never really putting anything near full charge into your batteries. It is designed to be a trickle/float charger for the chassis battery, running at 5-10amps or so, and then it kicks in more amperage as electronics need them. So if you turn on your headlights and AC and seat heaters and radio and roll down your electric windows all at once it might be putting out 100 amps, but the battery will never see this amount of charge going to it. So the same would be for deep-cycle house batteries. And I can attest to this from real world experience. When driving from a 50% depleted battery bank (140Ah), if the alternator were putting out it’s full 90A those batteries should be charged in less than an hour. In the real world it takes at least 3 hours at highway speeds to charge them up in our van. So I don’t think they’re seeing over 25A at a time just based on charging speed. An ammeter would certainly take the guesswork out of this! Again, that’s what we’ve done but I’m not certain that it’s true.

      For just coffee we have a jetboil with their french press attachment. I wouldn’t hesitate to use it in the cab of a car, either. That’s all we use it for (well, tea and hot chocolate too). It’s not very good for cooking anything except ramen, but it’s an option if you’re on the fence. It uses relatively little fuel, so a cracked window and a couple of minutes of cooking is all it takes for hot water. Not trying to push you away from induction, just giving you another option!

      1. Forgot to mention I cook on a one burner propane, Not inside my van. MAKES COFFEE and heats soup and cooks eggs with sausage and onions. So happy to have a shelter when needed.

  3. Hi ,I have a larger RV and the distances from everything is soo far apart. I installed the system and didn’t have to much trouble. My biggest issue is length of runs, wire size is needs careful thought. I keep thinking of my electricity teacher in high school, he taught us the best formula-: e/i times r which is. E
    I x R
    Whatever you want to find out just cover it and what’s left is your formula. So cover the R which is resistance and you have the formula E divided by I and so on. If in doubt use a larger wire.

    1. Ken, this is a good point. We let our minds slip the possibility of needing to make runs longer than the 10 feet or so in most vans. We’ll update our article with a wire gauge chart to take out the ambiguity.

  4. Hi!

    Thanks for all the great information. I have a couple of questions regarding fuses. I noticed that some of the connections require fuses but are not depicted to be hooked up to the fuse block. I was wondering if these could also be hooked up the fuse block or if they require separate fusing outside of the block.

    Also, what batteries do you recommend? Should I aim to get two 6V batteries over a single 12V one?



  5. Hi!

    Thanks for all the great information. I had a couple questions regarding the battery system. I noticed that you have two 6V batteries hooked up in series. I was wondering what pros and cons are of doing this vs a single 12V battery.

    I also had a question about the fuses. Some of the ones you depicted are not part of the fuse box. For example, the one going from the battery to the inverter. For these, should they be separate fuses or can it also be hooked up to the fuse box?

    Please let me know if you need any clarification. I’m fairly new to all this.

    Thank you!


    1. Alexis: the “in-line” fuses are usually separate from the fuse box for one of two reasons: location and size. The inverter takes a large fuse and the box is only meant for organizing smaller components. For the charge controller it’s a similar reason. It’s more efficient to avoid charging through multiple connections (fuse box is an extra connection) and allows you to make a short run from the cc to the batteries.

      Fuse blocks are best for a bunch of smaller components: lights, fridge, USB plugs, fans, etc.

      Good questions!

  6. Hey there!
    Amazingly clear and concise graphic, exactly what I’ve been looking for!
    Quick question: The spreadsheet shows one 150AH battery and links to a 12V battery on Amazon, but in the graphic it shows two 6V batteries in series. Is there an upside to one way or the other, other then doubling your AH (I’m assuming?) My main draws are a modified chest freezer (converted with a temp sensor to run a fridge temps) that only draws about 15AH/day and also a Bose sound system (pulls ~90W, but only a few hours a day). Would the setup above give a 300AH (two batteries in series), or do they work differently? Thanks again, really amazing article!!

    1. Caleb- when you wire batteries in series, the voltage increases but the Ah stays the same. So two 150 Ah, 6V batteries combined make one 150Ah, 12v battery. There’s no major advantage to either. Sometimes it’s easier to find quality 6v deep cycle batteries (and they’re easier to lift), but both options work great. The setup above seems like a great size for your fridge and sound system!

  7. I am planning long trips soon and want a refrigerator for longer stays. The Coleman Power Chill will take 1100 watts in 24 hours. I also want at least 200 w for my roof vent and evening lights. Plus will charge computer and cell phone. I am also thinking about a 650a ( 7800w) marine battery which might power these for 5 days of rain.
    If I later decide I want more panels, will this support them?

  8. My only question is why do you have your + and – connections the wrong way round on the battery!
    Check the image.

  9. sir
    i am aware of the solar LiFi internet and i want to know if my 3 watts solar panel can also be used as a photo detector to receive and transmit binary data for internet browsing kindly help out on this

  10. Hello,
    I am going to connect a solar panel to a electric stove for camping use. What is the setup required to power up the electric stoves of different wattage like 2000 W, 1800 W, 1500 W, 1100 W and 1000 W ? Is any possibility to reduce the wattage by using a high powered battery? Please send me the details through the mail separately for different watts if it is possible.

  11. Hello,
    Thanks for a great site and the info on it! I am going to furnish my campervan with 200W solar system, comprised of 2×100 pannels and the 20A PWM regulator which comes in the kit. In your 200W diagramme you show the two 100W pannels connected in series . Why is it so, if doing so you would get 24V 100W system instead of 12V 200W when connecting pannels in parallel? Is it related with the MPPT regulator’s way of work? Thanks for a clarification!

  12. Hi,
    Thanks for your article.
    most of the appliance I need to use in my trailer are DC powered (phone, laptop, usb device)
    Still I can’t fathom how to power them from a 12 or 24 v battery set that would be charged by solar panels.

    And it seems counter productive to invert the current from DC to AC just to be able to use the adapter provided by manufacturers.

    I there an interface that would allow me to take the current from the battery set and feed all kinds of DC devices like the interface you see on such Powerbank like Omnicharge …?

    thank for sheding some light

    1. A.

      You’re right; going from DC > AC > DC is inefficient. From the fusebox, the most common way to power DC electronics is to use USB ports and “cigarette lighter” 12V plugs. There are many step-up DC>DC converters that can take your 12V battery bank and charge an 18V laptop.

      Something like this can be found for most laptops except some of the newest high wattage ones, and would be plugged into a socket like this.

  13. Can you connect more than 3 items to the battery terminal connectors? I see that there are 4 items to hook up to the (-), then adding additional connections if hooking up to alternator?

    1. Allie: Yes, it is fine to “stack” ring connectors on top of each other. We recommend having the larger power connectors on their own terminal (such as an inverter). It is best if you use a little bit of dielectric grease or Vaseline on the connectors to prevent corrosion. Good question!

  14. Hey guys,

    Thanks for all the effort on this. It’s really appreciated.

    A quick question. What’s the reason have you guys chosen to not run the 12v circuit wiring (for lighting, fridge, 12v plugs etc) back through the load channel of the MMPT charge controller? This is the MPPT load channel purpose no?

    Thanks again!! 🙂

    1. Craig: Good question!

      The short answer is that there are good reasons to wire it either way. You are correct in that the reasons for the Load circuit are for the low draw 12V appliances. We feel that there are some benefits to just wiring the 12V circuit directly to the batteries for most vanlife situations (as apposed to solar backup systems and the like). Read a bit more on our thoughts in our charge controller article:


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