wire size, 4 6v batteries in series

Billinwoodland wrote:
I just came from my local NAPA auto store who usually are much more knowledgeable than the other chain auto parts stores, and they told me the 4/0 size cable was huge and not needed for my application. I'm no expert, what say you?

I'm somewhat of an expert! Answering this question without knowing how you use your batteries is folly.

First, large cable is usually recommended for large inverters. Do you have one of those?

And, 4 6v batteries in series is 24v. Is that what we're talking about? I doubt it, but it needs to be asked, and you don't want to pump 24v into your 12v systems.