AWG solar panel size?

[Spoulin207]

Not sure if I should use 10 or 8 AWG wire from my solar panels to my charge controller?? I have two 100w panels in series approximately 50 feet from my charge controller. Battery is a 12 volt universal battery UB8D. Any thoughts??

 

[newbostonconst]

Look at the size of wire coming out of the panel and go one size bigger because of the distance and you should be fine.

 

[OffGridInTheCity]

Not sure if I should use 10 or 8 AWG wire from my solar panels to my charge controller?? I have two 100w panels in series approximately 50 feet from my charge controller. Battery is a 12 volt universal battery UB8D. Any thoughts??

Panels usually have 10awg. For 50feet - 10awg is fine

 

[Jgb3]

https://www.calculator.net/voltage-drop-calculator.html
Fill this out you want less then a 3% loss

 

[WhiteHot]

You should be under 16 amps since you will be wired in series. 10AWG will work but less loss is always better and the cost difference is pretty small. Blue Sea has a great chart for figuring out wire sizing:

http://assets.bluesea.com/files/resources/reference/20010.pdf

 

[Substrate]

The references above show that one needs to pay attention to whether a chart is "one way" trip, or a "two way" trip for the circuit.

The bluesea chart specifies the "circuit length" as the "negative wire added to the length of the positive wire". I take this to mean a two-way trip.

Not knowing the difference, one can easily under-size, or over-size $ their cabling needs if the charts aren't specific as to what they consider a one-way or two-way circuit.

 

[Stepandwolf]

Given that most of the cable lengths are pretty long, most people will still choose the right wire even if only factoring one way length. I have been using and sharing just the wire gauge part of the chart and in that case, the left side of the chart is cut off where it refers to back and forth.

http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

 

[12VoltInstalls]

one can easily under-size, or over-size $ their cabling needs if the charts aren't specific as to what they consider a one-way or two-way circuit.

True. But I’m weird and upsize certain things- if 10ga meets the standard for the panel extension I’ll use 8ga.
Occasionally (rarely?) you may even get improved performance - especially at longer length runs when over-cabling low voltage.