I'll second that. Over my life I've had some shocks here and there, trains as a kid, working on the house as an adult, but nothing, I mean nothing was as painful as the zaps from the strobe units.

I would never have believe that a battery can deliver that sort of shock, but each time (and there were many) I ended up stomping around like Herman Munster yelling 'darn darn darn darn darn!' ony it certainly wasn't 'darn' sprewing from my mouth. And the buzz from the shock lingered for a while too. I could definitely see the possibilty of disrupting heart rhythms.