Neglected battery gone open-circuit?

[JohnD]

not familiar with this prob as I don't neglect my battery.

A disabled relative has an infrequently-used car (Peugeot 205, 5 years old) It has not been driven since about May. I tried to start it last week, it wouldn't, battery flat, no surprise. I got it going with jump leads and ran it for 20 minutes, turned off, batt too flat to start (no great surprise).

Yesterday I put the charger on it, load was >5A so charger cut out. I took the battery off and discovered the load was from the car (ignition off), battery seemed to have no load.

I'm assuming the battery is buggered, any comments?

 

[blondini]

The high resistance is due to sulphation on the plates. This is what happens when car batterys are left in a discharged condition.
Sometimes a degree of recovery is possible but it sounds like this one is too far gone.

 

[xerxes]

It might be possible to revive it by using an intelligent battery charger (as opposed to those really dumb ones you normally see in motor accessory shops).

For example.

In my view, they're worth the investment especially if you have any batteries that might be left unused for long periods, such as in a ride-on mower or a classic car.