Panel wiring question.

[littleharbor2]

So, when parallel wiring batteries it is beneficial to make your load and charging connections at diagonal corners of the battery. I have a friend who will be mounting 4, 12 volt solar panels on a trailer. They will be parallel wired. The panels have J boxes on the back so they will be wired + to + and - to -. Would it make any difference if the + and - home run wires came off the opposite ends of the array, as opposed to both from a single end panel?

 

[12VoltInstalls]

Would it make any difference if the + and - home run wires came off the opposite ends of the array, as opposed to both from a single end panel

Scientifically, “yes” in tiny tiny decimals.

In practical terms? No.

The phrasing in the question makes me wanna say that ‘I’ would parallel 2+2, and then parallel those two for the run to the SCC

 

[littleharbor2]

Thanks! I'll just have him come off the one end panel. It's a different wiring method but being that the J boxes are on the panels it seems the most straightforward way to go.

 

[glandpuck]

If you have 4 panels, you should be mounting them so all 4 j boxes are next to each other on the underneath side. This makes it real easy to service in the future and re-arrange whether you want them in series, 2 strings of 2x2, etc. That's for 2 rows of 2 panels. If your panels are all in a single row, side by side, then mount them so the shortest distance is between the j-boxes if landscape, if portrait no flexibility in this.

 

[littleharbor2]

If you have 4 panels, you should be mounting them so all 4 j boxes are next to each other on the underneath side. This makes it real easy to service in the future and re-arrange whether you want them in series, 2 strings of 2x2, etc. That's for 2 rows of 2 panels. If your panels are all in a single row, side by side, then mount them so the shortest distance is between the j-boxes if landscape, if portrait no flexibility in this.

The only glitch in that setup would be if the trailer roof isn't large enough to line them up that way (I'm picturing all four panels in portrait fashion. I'll find out in a day or two.

 

[12VoltInstalls]

just have him come off the one end panel

I’m confused how four panels in series or parallel could ‘come off one end panel’ though…

 

[littleharbor2]

I’m confused how four panels in series or parallel could ‘come off one end panel’ though…

Because they have junction boxes they can be parallel wired from box to box to box to box and the output comes out of the last box.

 

[12VoltInstalls]

Because they have junction boxes

Ok.
I was assuming there were MC4 terminated cables coming out of (diode) ‘boxes.’ Unexpected.

 

[littleharbor2]

Ok.
I was assuming there were MC4 terminated cables coming out of (diode) ‘boxes.’ Unexpected.

They're older Kyocera off-grid panels. The Kyocera "GT" (grid tie) panels have sealed diode boxes and MC-4 leads for series wiring.