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.

47 Comments

  1. Wingin' It with John on December 24, 2020 at 10:41 pm

    You videos are fantastic. Thank for sharing your solar intelligence.

  2. Enrique Aldana on December 24, 2020 at 10:42 pm

    👍

  3. James Pass on December 24, 2020 at 10:43 pm

    Do these same principals hold true for just 2 panels? I was told to wire my 2 panels this way because of the 30ft length I have to run the lines to my inverter(so I don’t lose voltage because of the long run.)

  4. Jacob Board on December 24, 2020 at 10:43 pm

    HEY THERE! Firstly, love your stuff! Your solar videos on YouTube have been incredibly helpful! Secondly, I really need a little bit of advice with the final part of my system and thought you may be able to assist. I am running a simple 200w solar panel system through Victron controller etc. BUT, I am not sure whether I need to earth the whole system? I don’t have an inverter so am entirely 12v… I would appreciate any help! Thank you 🚐🚐

  5. Will Creene on December 24, 2020 at 10:44 pm

    You didn’t leave the other video links in the description like you said you would 😉

  6. Talking Apes Podcast on December 24, 2020 at 10:48 pm

    Hi Nate, I don’t know if you have made video about wiring batteries but I thought I’d ask about wiring parallel vs. Series for batteries and what the pros and cons would be for each? If you have made a video on this then I’d love it if you would add the link. 😉 Keep up the great vids, I’m learning a lot!

  7. Kent Nelson on December 24, 2020 at 10:52 pm

    If I have 24 panels I assume I can wire 12 panels in series and the two series in parallel, correct?

  8. Jason Kim on December 24, 2020 at 10:52 pm

    Hi Nate!

    I am trying to convert a Ford E450 Super Duty 14 passenger van into my RV.

    And this is my first time ever with this type of work.

    I cannot thank you enough for all of your information.

    They helped me and gave me enough courage to convert my own van.

    I am trying to refer to your
    "300AH BATTERY BANK – 3X175W SOLAR – 2000W INVERTER – ISOLATOR WIRING DIAGRAM"
    Then I found that you have updated this diagram to
    "2000W INVERTER | 200-400AH LITHIUM | 200 TO 700W SOLAR CAMPER WIRING DIAGRAM"

    And I have a few questions about the updated diagram.

    Is the updated one better or easier to install than the old version?

    I noticed that you used 4 batteries with the updated version. Do you think 4 batteries are necessary? Would the updated version work with 3 batteries as well?

    You mentioned a few cautions about the old version. Does that mean you don’t recommend the old version?

    I found the "Victron Orion-Tr DC-DC Charger Isolated 12/12 30A" for new version is out of stock and Victron told me that it may be available for next month and I am a little worried if I get delayed with my work.

    Your advice will be very helpful and thank you for your answers in advance!

  9. JOSEPH SILVER on December 24, 2020 at 10:53 pm

    Thanks for the info. But can you list the parts and where to get them, including the controller?

  10. Robert Bundy on December 24, 2020 at 10:54 pm

    At age 75 and doing a 2017 Sienna LE MiniVan Conversion in Concord, NH., I have learned that you can damage the Renogy DC to DC MPPT charger if the solar is left on and the battery is off. My question. Does anyone use a relay to disconnect the Solar when the battery is switched off to protect the MPPT charger.

  11. Tom B on December 24, 2020 at 10:54 pm

    Thks, it comes for God, it goes to you, & you spoon it out to the rest of us.

  12. JCDriller on December 24, 2020 at 10:54 pm

    Thanks for the great video. I’m currently setting up my off-road camper trailer with solar, and due to the small size I can’t fit as much as I’d like on the roof. To get what I want, I’ll have two panels bonded to the roof, and using locking drawer slides I’ll have two more covering the first Two while traveling. Once arriving at camp, the drawer slides will be unlocked and pulled out exposing all 4 panels to the sun. I’m over doing it because I’ll likely be in partial shade and they will always be flat/not directed at the sun. I’ll be using 4x Renogy 175w flexible panels.

    I either need to run all 4 panels in parallel or run it in series-parallel. I’d like some power from the panels while traveling and 2 panels will be completely shaded. If I choose to run it in series parallel, I’m not clear which of the two panels in your example are in parallel and which two are series. I need to know which panels should be on bottom covered and which ones should be ontop exposed for the best charging while traveling.

    I know it’s an odd question, but I appreciate the input. Thanks again for your videos!

  13. rain0aldwaib on December 24, 2020 at 10:56 pm

    quick question
    if i have 3 panels
    can i just connect 2 in parallel to each other and the theird in series to both of them ?
    also if i have a 2 different panels with different current (say one with 5 amp and other with 10 amp)
    when i connect them in series how much current will i have or is it not possible to do so ?

  14. NanoCheeZe MEQUAVIS on December 24, 2020 at 10:56 pm

    can you do it the other way around, say hook up 4 panels in parallel, and then have another 4 panels in parallel, but then connect the 2 sets of parallels into a series? the reason I ask is because I have a yeti 1000, and it has a pwm charge port and an mppt charge port. I have 2 separate sets of mc4 cables going to each charge controller. When I take it with me on the road, I wanted to hook up my panels in 24v instead of 12v, can I simply plug the pos and neg together, and then attach the other pos and neg to a 24v controller? I couldn’t find any information on doing parallel series… only series parallel.

  15. McKinley Thompson on December 24, 2020 at 10:56 pm

    Can the MC-4 connectors and the standard solar connects be left on the roof of our van with no heat shrink wrap on them? Are these waterproof?
    Thanks!

  16. Argo Odyssey on December 24, 2020 at 11:00 pm

    Very very helpful mate. Got 6 panels . That I’ll be running into the roof of my camper in series and parallel. So this has given me the final insight I needed. 👌

  17. Ronald Southers on December 24, 2020 at 11:00 pm

    how do i know how big of a charge controller i need

  18. Percy Brown on December 24, 2020 at 11:03 pm

    If I get enough v from say 4 ea 290 w panels in series what does 4 more panels in parallel do for me?

  19. John Hubbard on December 24, 2020 at 11:06 pm

    Ok, so I did exactly as you instructed for my in Series/Parallel system with only the highest efficiency panels, but somehow I am using the same amount of tequila when making margaritas with my solar-powered blender. Seriously though, excellent series.

  20. Michael Nguyen on December 24, 2020 at 11:08 pm

    Hi Nate, your videos are incredible – thank you!

    Question – what is the determining factor for the current of the solar-RV battery system — Is it the solar panels’ total wattage divided by the battery’s charging voltage (e.g., 14.4V for a 12V battery system)? Or the solar panels’ total wattage divide by the solar panels’ total Voc?

  21. NEW GAMER on December 24, 2020 at 11:09 pm

    What are the advantages of these kind of ckt.?

  22. Tchiarito on December 24, 2020 at 11:09 pm

    Thanks for this, just what I needed to continue construction of my system!

  23. June Bradshaw on December 24, 2020 at 11:09 pm

    Does wiring in series like this make the system 12v or 24 v ? Thank you

  24. Sherry Moore on December 24, 2020 at 11:10 pm

    Just watched all of this series, thank you so much for taking the time to make a basic series! I would love to see the why you would wire in series vs parallel vs series parallel! Thank you!!

  25. Sharafat Ali Saleem on December 24, 2020 at 11:10 pm

    Hi Sir,
    I have installed 5kva solar system at my home. 5kva hybrid vmiii 48v solar inverter, 12x285w mono perc solar panels which are total 3420 watts and 4x126mah enersys batteries. First could you please tell me that how many panels (maximum watts) I can add to the 5kva system. Second is it compulsory to add same capacity (285w mono perc) of panels or different capacity of panels i.e 300w,350w, 370w, 380w, any from these can be add to system.
    Thanks

  26. Louise Villalobos on December 24, 2020 at 11:14 pm

    How do I get 220V dual phase from solar power?

  27. Da Ga on December 24, 2020 at 11:15 pm

    Nice job. Well done….Thanks

  28. Bill Cooper on December 24, 2020 at 11:18 pm

    Hello Great Video Thks. I wired my 3 strings, 6-250 Watt, 47 volts, 6.25 Amp panels almost the same way. 1st I ran both a positave and negitave wire back to my combiner box like yours making 6 wires total of 3 Negitive and 3 Positive from 3 two panel strings.
    HERES were I may be in trouble I than wired my positive and my negitive WIRES from each string starting with a negitive wire from the FIRST string to negitive bar in conbiner box then end to end positive to negitive ending with a positive wire and 282 dc volts at 6.25 amps.
    All is well but I wanted MORE AMPS so I took the last string REWIRED for PARALLEL Lost 47 volts and my Amps STAYED the SAME at 6.25 AMPS . I should of ended up with 18.75 AMPS but I did have 235 dc Volts thats correct. Anyone have any ideas. Thanks Bill

  29. jeepin johnny on December 24, 2020 at 11:21 pm

    hey – i understand HOW to do this but dont know WHY to connect either way !!

  30. Beautiful Dream on December 24, 2020 at 11:23 pm

    Thank you. Good information.

  31. Nowakezone Forever on December 24, 2020 at 11:23 pm

    Excellent video and I will subscribe and watch the rest of the series… pun intended.

    This helped me two days ago when I connected four Renogy 100 watt panels in series parallel to charge a Bluetti 240.

  32. Mark Freeman on December 24, 2020 at 11:26 pm

    Exceptionally helpful, thanks man!

  33. Stacy on December 24, 2020 at 11:26 pm

    I am planning on putting 5 175W solar panels on my van. If I can’t wire them in series parallel with an odd #, but want to keep amps down, what do you recommend?

  34. Russell Bruel on December 24, 2020 at 11:27 pm

    Hi Nate, I have been a fan of your channel for quite some time and appreciate everything you push out content-wise. I have a question regarding my solar plans for my van build. With the size of roof real estate, I will be using 3 x 150watt Newpowa panels. I did get a Victron 100/50 mppt smart solar controller. 2 questions: 1. how do you recommend wiring these panels and was this the correct controller to get? I appreciate your feedback and you as a content provider!

  35. Abdullah Aaref on December 24, 2020 at 11:28 pm

    Hi
    Can please make a video solar energy combine generator.

  36. Arturo Meuniot on December 24, 2020 at 11:28 pm

    You wire to what the open volt capacity of the controller then parallel. Your using way to many connectors. Your doing it to stay at 24 volts rather than the capacity of the controller.

  37. Alex Allen on December 24, 2020 at 11:29 pm

    You’ve helped me twice in 24hrs. First time was yesterday after I searched for an hour online before finding your video. This morning I had a different problem and I just clicked on the thumbnail with your face in it😂 as soon as I seen it and got my problem fixed within 30 seconds.
    Im sending you good energy ✌️

  38. J W on December 24, 2020 at 11:31 pm

    Got a 3s2p panel layout?

  39. Gaurav Singh on December 24, 2020 at 11:33 pm

    Hey Nate, is it ok to disconnect the solar panels from the MPPT/SC when the RV is outside in the sun? I plan on using the same panels to charge two separate devices so was planning to put an Anderson plug on the PV and remove it from one MPPT and plug it into my portable device that has an inbuilt MPPT. Do I have to wait for shade or cover the PV to unplug the solar panels from the MPPT or is it ok to offload them safely by just disconnecting the wires and plugging them into a new unit?

  40. Zeke Santamaria on December 24, 2020 at 11:33 pm

    Just double checking. If I have 4x190W panels, each outputting 20.4v and 9.31A, If I connect two in parallel then that’s 20.4V and 18.62A and then I connect the other two in parallel and I join them in series, will my output be 40.8V and 18.62A total?

  41. Nalani Askov on December 24, 2020 at 11:33 pm

    Hi Nate. Do you know what happens to the Voc when panels are wired in parallel? Does the Voc remain the same (assuming identical panels). I’ve read that wiring panels in series results in the Voc being added together. I have a system with a controller limited to 23 Voc (CTEK) and am trying to figure out the largest solar panel system I can create without exceeding the 23 Voc. If you could point me in the right direction, it would be greatly appreciated.

  42. A&K Air Technologies Kris Kanev on December 24, 2020 at 11:34 pm

    Thank you man I like the way you explained everything

  43. L L on December 24, 2020 at 11:34 pm

    There are no links in the video description ……….. just FYI for your dyi project maybe put links where you say they will be?

  44. Foryou Tosee on December 24, 2020 at 11:36 pm

    Imagine that not everybody who wants to learn from your videos is a native English speaker! So don’t try to get a fast speaker entry in the Guinnes Book but give people time to follow your words and add some pauses… This video would not loose quality if it lasted 6 minutes instead of 4:02! Tank you for considering this feedback.

  45. MykSr on December 24, 2020 at 11:38 pm

    😎

  46. R Rivers on December 24, 2020 at 11:39 pm

    We have two 100ah AMG batteries. Should we install a circuit breaker of 50amp between battery and charge controller (wanderer/renogy)? Or install a switch and an ANL FUSE 50amp.
    We only have two 100 w solar panels

  47. Ed Stoneberger on December 24, 2020 at 11:40 pm

    Series, parallel, series-parallel, do you cover why you would use one configuration over the other?

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