The story can’t be found in my searches a few weeks ago but some Catholic nuns were in Africa doing missionary work and giving aid to sick and impoverished children and adults there. African men attached cables from a pickup truck and shocked the women repeatedly.
I know I remember those details because they upset me.
I have no idea if extras were required such as water to improve conduction or anything else.
But I remember the newspaper reports. Possibly mid to late 1960s.
The only way to shock people from a standard pickup truck would be via the ignition system, not the starting battery.
12 volts DC is too low. So is 24 volts DC. Won’t overcome your skin resistance, even when wet.
Nothing at all happens if you wet your fingers and touch a 12 volt car battery’s terminals.
Your tongue has extra sensitive cells and that’s why a 9V battery makes it tingle with the very close together terminals.
You are in far more danger from a car battery falling on your foot, than from the 12 volts DC.