Right, but that’s not exactly electrocution, that’s just burning. Through a metal, 12V will be more than enough to create a current that makes the conductor very hot, but through a human it likely will not be able to cause any damage whatsoever.

Could that be used as a form of torture? Absolutely, not disputing that. But for electrocution, a car battery would not do, and for burning a blowtorch would be more effective.