On 10/05/2012 21:03, Tim Lamb wrote:
Newish car battery employed to power pony field electric fence. Likely
to have been left connected well beyond the fully discharged state and
possibly exposed to overnight frost.

Won't take a charge! Yes, I know, throw it away. However, horse person
has gone off with my sound spare. Is *over* discharging an issue? or...?

regards
if it is not sealed ... I recovered one battery by washing out then
filling with battery acid (not distilled water) .. and left it on long
slow trickle charge ...