Originally Posted by wingnut60
Another good place to find larger gauge stranded wiring is a mobile stereo shop...The amps they use require heavy duty wiring.
Yea, you are mostly likely to find #8, #4, #2,#1, and #0 guage wire at car audio shops. Plus they'll have all the accompanying connectors you'll need. Big amps require big current, which is why they have such big cable there.
However with solar, bigger wire usually means less wire resistance which is key to maximizing the voltage at the battery and maximizing current efficiency through the cable without being wasted as heat. General rule of thumb is do the thickest you can handle within your budget, routing, cutting and crimping ability etc....