On 06/04/2018 15:02, Dave Plowman (News) wrote:
In article ,
newshound wrote:
Going slightly OT, pulled an apparently dead 105 AH leisure battery out
of a caravan yesterday (hadn't been used for months and the charging
circuit claimed it was dead when on mains hookup).

Gave it best part of a pint of demin water and stuck it on charge on a
traditional charger, this morning all the cells are bubbling nicely and
it's showing over 14 volts immediately after disconnection. Will stick
it on a smart charger for a few days but I'm quite hopeful.

Sadly, voltage is no real check for a lead acid. You need to measure its
capacity in amp.hrs. No real point in keeping a thumping great 100
amp.hr battery if it's well down.

Voltage tells you if you have one or more bad cells. Also, it will
indicate self-discharge.

Depending on what you do with it, as Tim says they may still be useable
even if the capacity is down. The owner of this one tells me that in
fact he hardly uses the battery (probably why it has been neglected)
because he almost goes straight on to mains at sites.

I will do a bit of a capacity check once it has had a good charge.