A battery cable bigger than #0 is probably overkill. I like to make up my own battery cables, using #0 arc welder wire. Welding cable has MUCH thinner individual wires in the bundle, which makes it more flexible, and gives it a higher current carrying capacity for any specific diameter, since a wire tends to carry current on the surface of the strand, and having several hundred strands like welding cable does gives a lower resistance than regular battery cable.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!