How to Wire Solar Panels in Series Parallel



This video will teach you step by step how to wire your solar panel array in a series-parallel configuration.

Wiring solar panels in series-parallel is just a matter of connecting The positive and negative wires for neighboring solar panels together creating individual series wired solar panel strings; then wiring those series wired strings in parallel by connecting the positive and negative of each series string to a MC4 Combiner to the wire that goes to the charge controller.

For the example of todays video; I am going to be wiring 4 100w rich solar panels in series-parallel; right over here.

I’ve already used my multimeter to determine which wires are positive and which wires are negative and noted that with a bit of red heat shrink on the positive wires AND covered the panels with cardboard so I’m not working with live voltage.

First, I want to wire the outside pairs together in series. That means wiring the positive to the negative on these two panels. And wiring the positive to the negative on these two panels.

Now… I have two pairs of panels wired in series. Now; I need to wire these two series wired strings in parallel.

To do that, I’m going to take all of the positives from each series wired string of solar panels; and attach them to an MC4 combiner.

Next, I’m going to take ALL of the negatives from each series wired string of solar panels; and attach them to an mc4 combiner.

Then I can attach each of the positive and negative mc4 combiners to the wires that will go through the roof and connect to the charge controller.

If the array needed to have fuses, I would attach the MC4 fuses to the positive MC4 combiner between the combiner and the panel wires. Some arrays need fuses; some don’t. You can rely on my free wiring diagrams to show you when to use them or not, but we will be covering the ‘why’ in a future video; so consider subscribing.

If you have more than four panels, the theory is completely the same. If we had 6 solar panels, they could be wired in a 3 panels in series with the 2 series strings in parallel.

OR… They could be wired 2 panels in series with the 3 series strings wired in parallel.

More panels? Same concept:

16 panels. series strings of 4 panels with the four series strings wired in parallel.

Now, something to note. All series strings really need to be identical. So; 5 solar panels cannot be wired in series parallel BECAUSE it’s highly not recommended to have an array with a series string of 2 panels wired in parallel with a series string of 3 solar panels.

Now… why would we use series parallel? Series-parallel allows us to keep the voltage from our solar panel array high enough for the MPPT charge controller to effectively do it’s job but low enough to stay under max voltage rating of the charge controller.

It also allows us to keep the solar panel array amps low enough we can effectively use smaller wire throughout the entire array without worrying about excessive voltage drop; but we are going to talk about that in MUCH more detail… next week.

I hope you found this video helpful and if you did, it’d be awesome if you’d share it with somebody or a group who you think could benefit from it and leave the video a thumbs up. Drop any questions you’ve got in the comments section below. Subscribe if you want to see more DIY camper building tutorials and I will see you in the next video.

32 comments

  1. What about connecting to different sets of panels into a separate panel input socket…I have lots of holes where wires go in the bottom of the inverter. I can't get the panels on the main roof it's shared but I can put them up at the back of house and can use the front too. Ask questions if you don't know what,I mean. LoL I don't just want to try it just incase a burn something out in the inverter FRONIUS 3.6

  2. Question, I have four 340 watt 36 volt panels and a 445 ah battery bank with amp80 outback charge controller , what’s the best way to wire my panels to get my battery full each day

  3. Can I connect my 2 solar panels, and have the positive and negative wires connected to the wires meant to go to the solar charger, but not have it hooked up to the solar charger or batteries yet? Like have the solar panel side hooked up for a few days without the other side of the wires hooked up to anything? Would I have to keep the solar panels covered from the sun??

  4. The Series is fantastic, question Can I connect 4s to 3s 2parallel solar panels, to ending in one string of 7 in series, for a total of 10 panels, I'm trying to find out which is a better parallel string of 5 which yield 263.0 volts with 4400 watts or 8 in series will yield 420.8 volts with 3520 watts and the 4s combine to 3s2p, is all relate to the limit 450 volts for the inverter and 4500 watts also a limit of the inverter, panels have 440 watts, 52.6 Voc, and 10.2 amp of Ioc, imp 9.8 amp

  5. Does anyone know where the links noted in this video are? Especially the previous videos mentioned that provide more background. Appreciate any help.

  6. Great video as always. Can you elaborate why it's not recommended to have series-parallel strings with different numbers of panels? Is it bad to have different voltages from each string coming together? I was thinking of adding 2 more panels on my trailer roof to have 4 in total, all connected in one series string. I currently have a pair in series as well as a second pair in series in a portable suitcase that come together at the branch connectors (I only connect the portable suitcase when at a site). Each pair is identical in panels, voltage and current. The setup is great but wanting to add a bit more capability on the roof.

  7. Can you connect 2 panels in parallel then connect them in series? It would produce the same watt output. Any advantage or disadvantage in either configuration.

  8. Great video Nate. Thanks for posting. I do have a question. I have 2 banks of 2 100 watt panels in series parallel and am wanting to add a third set of 2. My MPPT is a Victron 100/30 right now,, should I upgrade to a larger one before I add the third bank. Thanks

  9. I'm installing four 210 watt solar on my sailboat. I considered series connection for high voltage/low amps. But my concern would be shading on panels lowering output.

    Would it be better to wire port side in series, starboard in series, then the two in parallel? This would reduce the chance of sails shading on side and lowering output.

  10. I have a MorningStar TriStar TS 45 pwm charger can I wire my 240w panels in both series/parallel or it has to be one or the other

  11. Great video a guy I bought 4 solar panels from recommended your video for a series-parallel setup. So here's my question

    I have 5 renogy solar panels
    4 x 200x 1 x 150 in series now

    I bought 4 350 REC solar panels that I wanted to have in parallel

    Would you recommend using 200W and 350W together in a series parallel connected to a epever 200v/60A charge controller?

  12. Your style of explaining things is absolutely great. This is confusing stuff and you do a great job of demonstrating.

  13. Great video. I intend to have 3 panels in series permanently mounted to the roof of my camper and 3 panels in series that I can deploy on the ground. These would be wired to the charge controller in parallel. Does it hurt anything if I decide not to plug in the ground set (leave them in storage)? If I'm stopping somewhere for only 1 day, I may decide to not connect the ground set of panels. If the charge controller is sized correctly, this shouldn't be a problem, yeah?

  14. Noob here.. just wanna know..
    1 – series: positive to negative .
    2- parallel : negatif for negative
    positive for positive..

    when connecting each units of solar panel, can i just connect all the negatives together..and all positives together..?

    in this video i saw u
    connect the + to –
    then the other videos i saw u combine all the negatives in one and all positives line in one..

    i mean…what is the differents?

    I am stupid of this…that is why i am here to ask. lol

Leave a comment

Your email address will not be published. Required fields are marked *