In message
,
Andy Dingley writes
On Feb 20, 7:48*pm, Ian Jackson
wrote:

There's no way that a 500mA wall wart could ever deliver enough current
to kill a car battery.

It can do it if it's connected in reverse to an already-flat battery.

It's unlikely that a 'flat' battery would have zero volts in it. More
likely is that one cell has dropped to zero, or even become
reverse-charged. Instead of 12V, the voltage would be 10V - or even 8V.
This is more than enough to blow a reverse-connected charger to buggery!
--
Ian