Unequal Length Cables in Solar Panel Array ... Problem?

[chadmichael]

My PV array is 4 x 100W panels. Two series strings combined in parallel to create a hybrid array. In order to parallelize them on my roof, the 2 ft connectors that come attached to the panels need extension. I bought some extenders and set it up, but I'm immediately aware of a potential problem. I only bought extenders for one of the sides of the parallel combination. Here's what I mean:




So, now one side of the cables feeding the positive side MC4 Branch Connector is 5 ` long ( the 2' panel cable plus a 3 foot extension) while the other is still two feet in length. In addition to the length difference, there's an additional connector on that longer side adding more resistance. It seems to me that this is a balancing problem, with one side of the positive cables having more resistance. But maybe this is corrected since the solution is mirrored on the negative side.

Do I need to extend the other sides to make everything even, or is it perhaps already balanced?

 

[Brett V]

Nope. Won't matter at all.

 

[Mattb4]

Not necessary to have the same length.

Edit: Brett beat me to it by a gnat's whisker.

 

[chadmichael]

As in, doesn't matter for safety? or doesn't matter in any way at all, including efficiency? I'd buy more cable if it meant not losing some of the charging potential of the panels.

With a battery array it matters alot, yeah? How is this different?

 

[Brett V]

As in doesn't matter at all. Your panels are supplying their max available output. They don't have to balance like parallel batteries do.

 

[wpns]

You are fine, your solar panel current is a lot less than your battery current. The only measurable impact of adding more wire would be to reduce your panel strings output.

 

[millsan1]

I would bet that vast majority of installs have different cable lengths.

 

[chadmichael]

You are fine, your solar panel current is a lot less than your battery current. The only measurable impact of adding more wire would be to reduce your panel strings output.

Yeah, but reducing the output of a string is not desired. The cable to even these lengths is negligible. But maybe we are talking a minuscule amount of loss here

 

[wpns]

It is miniscule, probably not even measurable.

 

[timselectric]

If those losses were sitting beside a penny.
I would recommend that you pick up the penny.