Over 50+ years of maintaining high-current starting systems, I have learned that within reason, bigger is better. Another consideration is not only the cross-sectional area of the wire, but the number of strands. The hair-fine strands of welding cable will carry far more current, with less voltage drop, than regular battery cables will. Current tends to flow along the surface of strand of wire, so 500 strands will carry more current than a 50-strand cable with the same diameter.
Jerry
