I've still got a scar on my wrist from a car, was fucking about changing the intercooler on my old Pulsar, and the ally pipes run really close to the battery terminals, somehow managed to short my metal wrist watch and intercooler pipe against the positive battery terminal, and the current must've heated my watch up to a few hundred degrees as it actually melted a bit of the steel strap and burnt itself into my wrist

So I'm always a bit weary round batteries and stuff these days!