In message , The Natural Philosopher
writes
Rick Hughes wrote:
On 10/05/2012 21:23, Fredxx wrote:
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

Car batteries are designed to deliver lots of cranking amps. They are
generally destroyed by a deep discharge, or the very least have their
capacity severely reduced.

Use a leisure battery which is more rugged and can cope with deep
discharge, or should I say are less damaged by a deep discharge. I'm
pretty certain you can get devices which switches off a load once
battery volts get below 11V.
Any boat store will sell these - they cut your battery to make sure
you have enough power to start engine

and then the ponys get out..

buy a trickle charger and a waterproof pot...

Or a mains energizer! Actually these seem to *tick* on medium wave radio
reception.

Escaping ponies only an issue with a stranger as the regulars avoid the
tape whether it is energised or not. Hence the probably flat for weeks
battery:-(

regards

--
Tim Lamb