Salvo wrote:
Half a volt? That's huge! You're throwing out numbers beyond reality. I've found just about everybody installs cabling significantly bigger than necessary. No one wants to throw away watts.
Your manual states 0.5V drop is OK?
Half a volt actually isn't that much in the real world. It's at the high end of what would be acceptable in a 24v system (2%), but certainly possible. A 50-foot run (+ and - wires) of 4-ga at 30 amps would get pretty close to that. Smaller wires, even more. And with higher system voltages, 2% would result in even more of a drop -- figure a whole volt in a 48v system. Most manufacturers recommend a 2-3% drop max (Morningstar and Xantrex are two of them off the top of my head).
If you can afford to run 2/0 from your controller to your batteries, then kudos to you. But last I checked, 2/0 copper is near $5 per foot...and most people wouldn't/couldn't spend that much to wire up their batteries.
