How are you supposed to wire two solar panels to the same charge controller?

[Off Grid]

Hello again my fellow solar fanatics,

We have two 260W solar panels that we plan to hook up to an MPPT charge controller. However, I can't figure out what type of wire we're supposed to use from the panel to the controller, especially since nearly every charge controller we've researched has screw terminals, which aren't anything close to the H4 connectors from the panels themselves.

Do we need another device in between the two? If not, how do we safely connect the panels to the charge controller? Thanks for you help!

[ButchDeal]

Hello again my fellow solar fanatics,

We have two 260W solar panels that we plan to hook up to an MPPT charge controller. However, I can't figure out what type of wire we're supposed to use from the panel to the controller, especially since nearly every charge controller we've researched has screw terminals, which aren't anything close to the H4 connectors from the panels themselves.

Do we need another device in between the two? If not, how do we safely connect the panels to the charge controller? Thanks for you help!

since you have an MPPT you can put your modules in series. The simplest thing to do is to buy a solar cable extension with male/female connectors already on it of a length twice as long as you need. Cut in in half and you can wire the cut ends into your charge controller.

[Off Grid]

since you have an MPPT you can put your modules in series. The simplest thing to do is to buy a solar cable extension with male/female connectors already on it of a length twice as long as you need. Cut in in half and you can wire the cut ends into your charge controller.

Thanks yet again, Butch. Last question: where do I connect the two panels? Can I just screw both exposed leads down in the same terminal on the MPPT?

[ButchDeal]

Thanks yet again, Butch. Last question: where do I connect the two panels? Can I just screw both exposed leads down in the same terminal on the MPPT?

connect the two modules in series, Plus to minus, then one extension on each of the remaining leads


CC negative terminal ---extension cable.--------module one ++++----module two+++++ extension cable ++ CC positive terminal

[SunEagle]

Even for a small solar / battery system the person doing the wiring needs to understand electrical circuits so they can do it safely.

I would advise Off Grid to go read some books on electric circuits and solar battery system installations. Otherwise you could hurt yourself and others if you do not understand what you are doing.

I am not trying to beat you up I am just trying to make sure you don't get hurt since electricity can kill if you do something wrong.

[Mike90250]

The cables from the solar panels should be marked + & - [ plus & minus ] To wire the 2 panels in series, you connect a + (of 1 panel) to a - (on the other panel) Then you have 2 leftover leads from the panels, One is + and goes to the + terminal on the controller. The remaining lead is - and goes to the - terminal of the controller

But First, you connect the controller (properly - it should have come with instructions) to the battery so it's brain has has a chance to boot up before the panels are connected.

[Off Grid]

connect the two modules in series, Plus to minus, then one extension on each of the remaining leads


CC negative terminal ---extension cable.--------module one ++++----module two+++++ extension cable ++ CC positive terminal

Sounds great! Looks like the extension cords are pretty cheap, so this should work just fine for us. And just because I'm curious, what would you do if you wanted to wire them in parallel?

[sensij]

Sounds great! Looks like the extension cords are pretty cheap, so this should work just fine for us. And just because I'm curious, what would you do if you wanted to wire them in parallel?

Typically, you'd use Y-connectors to combine the two plus leads into one lead to the CC, and the two minus leads into one lead to the CC. You have to be careful to stay within the amperage rating of the connector. Something like this:

https://www.amazon.com/Renogy-CNCT-MC4Y-Branch-Connectors-connector/dp/B00Q5W30FY

Once you get more than two panels in parallel, you should be fusing each of the parallel circuits. Y-combiners and in-line fuses can work for small systems (again, look at the ratings), but a properly designed combiner box is preferred for bigger systems.