I've used both. One 16 volt has way better cranking power than two 12 volt. 15-1 572 spins with full timing and ignition on hot or cold. Standard Dakota style starter. Mine is an XS with a 30 amp power supply to charge it. When using the two 12 volt, I had a jump box with me that plugged in under the dash. No more. The power and ground are 0 gauge. Bought a 16 volt regulator that fit my alternator. Doug
