Forum Discussion

Vintage465's avatar
Feb 08, 2019

Wiring solar panels in series with three panels

So I am now messing with the idea of configuring my solar into a series set up. I currently have 2 each 150w Samlex panels. I am going to put a third matching panel up there.......that is all the realestate there is on the roof. So I've heard from a pretty "well read" friend of mine that I can wire two of the panels in series and the third one can just be wired in parallel................long as you use an MPPT controller. Thoughts on that idea?

Thanks

38 Replies

  • Ed_Gee wrote:
    Better make sure the combined maximum voltage of your three solar panels in series does not exceed the maximum voltage input specifications of your solar charge regulator. If they do, then you need install them all in parallel instead.


    Right. I have run my three 100w (22Voc each) in series ok at 66Voc with my Tracer MPPT (can do 90-100) but can't with my Eco-Worthy MPPT ( can only do 42 --but newer ones can do 50)

    As it happens, amps to the battery is the same whether in series or parallel in my set-up. Also get the same amps to the battery with the three in parallel and using my Solar30 PWM ( approx 18.6 amps at best)
  • Better make sure the combined maximum voltage of your three solar panels in series does not exceed the maximum voltage input specifications of your solar charge regulator. If they do, then you need install them all in parallel instead.
  • dom101 wrote:
    .. some moron had hooked up both solar panels in series then hooked to one 6 volt battery.
    ..and no controller. Wonder where morons get their electrical education.
  • Better check the voltage of each panel with it in very hot sun. When I bought my last MH, I could smell sulfur smell in the heat of summer. I pulled the battery covers and discovered some moron had hooked up both solar panels in series then hooked to one 6 volt battery. Each panel was putting out 19 volts so that was total 38 volts going to one 6 volt battery. I also noticed that battery was a different model than the rest. Guess he didn't figure it out. Who knows how many batteries he went through
  • 3 series or 3 parallel is normal

    (2) series and (1) parallel, the single panel has to equal the voltage of the (2) in series

    its a voltage thing

    EXAMPLE:
    you don't put 12v battery in parallel with a 6v battery

    but if you have (2) 6v in series you can parallel a 12v battery to them, because the (2) 6s make 12v
  • With three panels you need ALL in series or All in parallel. No series/parallel until you go four panels.