DIY Solar – Wiring Different Solar Panels w/ Same Amps, Different Volts & Watts

August 8, 2016

DIY Solar Tips, Solar Panels, Videos

, , ,

If you’ve got very different solar panels, without question, the best way is to have each solar panel have its own independent charge controller. If that’s not an option, however, we’re here to give you some DIY ideas and demonstrate the best way to wire up mismatched solar panels.

In the demonstration below, we are doing the same amps, with different volts and watts. So, we have two solar panels, a 100W 24V solar panel, with a short circuit current of 3.03A, and an open circuit voltage of about 44V. And we have a 50W solar panel, with the Isc, the short circuit current, also at 3.03A and its Voc is half of that, about 22V. We are going to show the power that they output going through an MPPT charge controller, into a 12V battery. And then we will be able to see independently how much power they put out and also how much power they put out if we wire in series and in parallel.

Let’s get started…

About Author

Amy Beaudet
Amy Beaudet was in the solar industry at the altE Store from 2007 until her untimely passing in 2021. She was a sales rep, instructor, and an all-around solar evangelist, sharing her passion for solar around the world. When whe wasn't at work, she enjoyed sailing and skiing - but odds were good she was still talking about solar on the boat or on the slopes. See more of Amy Beaudet's blog posts.

7 Comments

  1. Pingback: Wiring Mismatched Solar Panels in Series & Parallel | altE Solar Blog

  2. Russ

    So I have an 1800 W array (9 of the same 200W panels) in a 48v system (Magnum PAE 4448 and Midnight Classis 150) and these panels are no longer manufactured, if I wanted to add 3 or 6 more panels to boost my charge rate to my 8 Rolls 468amp hr batteries what should I be trying to match up in terms of specs on the 3 or 6 more panels? Is there something that is more important then the other to try and match up when adding different panels?
    Thanks

    1. Amy Beaudet (Post author)

      That’s a tricky one. You’ve got plenty of space left on the charge controller, so it is tough to just buy a second charge controller for the new panels (which would be the easiest solution). The second best option would be to select the new panels so that the volts and amps add up to equal the strings you already have. For example, if you have three 60 cell 200W panels in series, the total Vmp of the string is probably about 96V, and Imp about 6.25A. So, theoretically, you could get two 250W 72 cell (24V) panels, and one 100W 36 cell (12V) panel. That would give you the same volts and amps in that string. I’m about to release a video that shows doing a similar thing with multiple 12V panels in parallel with a 24V panel.

      Anyone else out there have any suggestions?

      1. Russ

        Thanks for the quick response Amy!

        The specs on my current 9 panels (Canadian Solar CS6P-200P) are as follows:

        Vmp 28.9V
        Imp 6.93A
        Voc 36.2V
        Isc 7.68A

        I have a 10th panel but it wasn’t installed as the only way to install would be with the 9 panels. So you are saying I could actually likely use the 10th panel I have an buy 2 additional panels the add up to something that would give me similar volts and amps?

        Thanks

  3. don

    i was hoping to get an answer about the magnum pt 100 charge controller, i’m wondering if it can handle a 1920 watt 12 volt system? thank you for your input. Don

    1. Amy Beaudet (Post author)

      1920W / 12V = 160A. The PT100 can output up to 100A. You can either switch to a 24V system (1920 / 24V = 80A), or use two charge controllers, each managing half of the panels.

  4. Pingback: DIY Solar - Wiring Different Solar Panels w/ Same Watts | altE Solar Blog

Comments are closed.