SNIP
Everything but the shock part was fine. You can't get shocked by a 12V
> battery. There just isn't enough potential. The biggest problem if your
> wrench shorts out is that the wrench will get very hot and you might burn > your hand.
>
> -Bruce
>
Skin resistance usually prevents getting a shock at 12 VDC, but..........
Ever kiss a 9 VDC battery? No shock?
Or, consider if you interrupt a current flowing into an inductive load, like a fan blower motor. You can get a few hundreds of volts inductive transients, quite enough to make you jump.
Ed