Combine Panel Wiring at Panels or Controller

[kittysmitty]

I'm installing 3 135 watt 12 volt panels using a pole mount. Does it make a difference in performance if I run the panel wires separately to the change controller and combine the wire there, or combine the three panels at the pole and run one set to the charge controller. I would run #10 wire if separate, or #6 if combined. Current of each panel is 7.45 amps and distance about 20 feet, Cost of wire is NOT a Factor. Thanks

[DamonHD]

Unless you get different shading (in which case you could consider a multi-input controller), or you end up with different aggregate series resistance in the wiring somehow, then it should make no difference if I've understood you correctly.

Rgds

Damon

[lifer]

You might consider connecting all three panels in series (if your charge controller allows a bigger input voltage) and run with only two #10 wires.

[Flux]

Depends on the circumstances, the best way is to use the 3 panels in series with a mppt controller but as Damon mentioned no panel must be shaded when the others are in sun.

With direct connection and no mppt then it doesn't matter if you use thin individual leads or thick combined leads. Either way will still work with panel shading.

There is little to gain with mppt if you use 12v panels on a 12v system. If there is no shading problem then mppt will give better results with the panels in series and could be worth the more expensive controller, it will reduce line loss to a low level and get you better charge on bright winter days when the batteries are low.

If you go for mppt then make sure it is a mppt controller, there is a lot of doubtful stuff for sale.

Flux

[kittysmitty]

Let's clarify. Panels will be in parallel. PMW controller. Cost of wire in NOT a factor. Cost of controller is.

[Flux]

Separate wires of #10 will be slightly better than combined on #6 but either will be ok.

Flux

[WindriderNM]

It would be easier to test things or if they are separate.

[XeonPony]

Go cheap on batteries, go cheap on the solar panels, but NEVER go cheap on the charge controller! It is the heart of your system!

I starved to get the Morning star Mppt 60 back 4 years ago when it cost 800 bucks, but it has been worth every cent ten times over!

First controler was an Mppt sunsaver 15, it was a huge boost in system performance, I swore I'd never use any thing ells again, if you rely on your solar get a mppt controler!