[quote=4100 Fire Truck]I'm guessing that 6 volts will be a bigger shock than 12 volts as it has twice the amps, AFAIK.
Nope. 6 volts can only push 1/2 the amps thru the same resistance (your body in this case).
I used to check 9 volt batteries (the little rectangular ones) by putting my tongue on the terminals. Tingle = good battery, no tingle = bad battery.