In article ,
The Natural Philosopher wrote:
A 12v supply and an inductor with wet hands and an arcing contact is
quite enough to generate several seconds of 400vAC. Starter motors draw
a few hundred amps on starting..

It would require some 'skill' to disconnect the battery while the starter
was turning...

This story will turn out to be the usual urban myth. Where they've left
out the faulty mains battery charger he was connecting - or whatever.

--
*Wrinkled was not one of the things I wanted to be when I grew up

Dave Plowman London SW
To e-mail, change noise into sound.