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How to Wire Solar Panels in Parallel

There are three ways to wire a solar panel array; series, parallel, and series-parallel. If the needs of your solar electrical system call for parallel wiring of your solar panels, this blog post will teach you how to wire your solar panel array in parallel.

Wiring solar panels in parallel simply means combining all of the positive wires together into one wire that will go to the charge controller and combining all of the negative wires together into one wire that will go to the charge controller.

To combine the wires from the solar panels, you will need to use MC4 branch connectors.

  • 2 to 1 MC4 Branch Connector
  • 3 to 1 MC4 Branch Connector
  • 4 to 1 MC4 Branch Connector
  • 5 to 1 MC4 Branch Connector

Depending on your choice of panels, you may also need to incorporate fuses into your parallel wired solar panel array.

  • 15 Amp MC4 Fuse
  • 20 Amp MC4 Fuse

All of the diagrams below show a parallel wired solar panel array with fuses in their proper place. If your setup does not need fuses, simply ignore the fuses and connect the positive wires directly to the branch connector.

How to Wire Two Solar Panels in Parallel

How to Wire Three Solar Panels in Parallel

How to Wire Four Solar Panels in Parallel

How to Wire Five Solar Panels in Parallel


Jay

Tuesday 24th of May 2022

Thank you for your videos! They are really good. I've never built a solar system before, but ready to give it a go! Going with 4 each 230 watt solar panels (used panels from SANTAN SOLAR) the Max Pwr Current is 7.78A and Max power is 30 volts (open circuit is 37 volts). After watching your videos today, I am going; 'series parallel' for sure. My question is that I believe I need a MC4, 15 amp inline fuse on both of the positive cables coming from the solar panels? Does that sound correct?

The 15 amp basically comes from the fact the generator (Bluetti 200 max) has a 15 amp pigtail for 'solar in'.....not much more science than that! The only thing I am absolutely sure about is the 10 AWG wire size....got that nugget today!

Thanks, Jay

Jeff Schu

Sunday 20th of March 2022

Are there any issues with not utilizing all the ports of a 3 - 1 connector? ie: If I want to run 3s2p, then upgrade to 3s3p eventually.

rob paul

Saturday 7th of August 2021

Hi Nate - I'm looking to run 3x Renogy 175w Mono panels (Optimum Operating Current 9.75A) into a Victron SmartSolar MPPT 250/100-Tr Solar Charge Controller 250V 100A with Bluetooth. The distance from the Walfront 2P 63A breaker (what was in stock) you recommend to the controller is about 2ft. The distance from the controller to the inverter is about 3 ft. I can't seem to get a ferruled 6 awg cable into the Solar controller as you recommended in the diagram I purchase.

Can you advise if an 8awg cable is acceptable?

rod browne

Tuesday 18th of May 2021

Hi Nate, I'm going to install one of your designs on the flybridge roof of my boat (2 panels, one string to start with and work up to 6-8 panels, two strings) and want to install the end product wiring size requirements at the start. My round trip wire run is about 80 feet with some constriction getting off the roof. Smallest wire size from panels to controller will be needed. Anticipating Renogy 160W (if they are still available) or Renogy 175W panels to Victron 100/50. I'm a bit confused however about where and when I should wire series or parallel or series/parallel with the branch connectors to minimize the wire size requirements getting off the roof. Can you offer suggestions or advice? Thanks, Rodd Browne

Nate Yarbrough

Sunday 23rd of May 2021

You want your solar array voltage to be at LEAST 20V higher than your battery bank charging voltage and you solar array amperage under 30V so you can use MC4 connectors. To do this, you'll have to do some form of series parallel to make this possible. Pure series would exceed the max solar input voltage of your 100/50.

Chris

Thursday 25th of March 2021

Hello Nate, love this blog. Can I wire 3 200W panels going one>two>Three using two 2 to 1 MC4 Branch Connectors? Thanks, Chris