Reviving a dead car battery.

[CortinaDave]

Today I'm attempting to recharge a battery that's been lying, unused on my cortina for around a year. It's a 640a heavy diesel battery and was excellent before it sat doing sod all. Turned the key in the cortina and got not even so much as the oil light so its stone dead as expected.

 

Am I wasting my time even trying to recharge it? Anyone left a battery dead for a long time and successfully revived it?

[Stanky]

I've revived a couple of batteries from a similar state, though not ones which have sat for so long.

 

may be worth checking to see that there is still electrolyte covering the cells (assuming you can get the caps off) before whacking it on a trickle charger. I'd suggest doing it outside, on some kind of solid surface which is covered against the elements  - a lean to or somesuch would be good.

 

give it a few hours and see if its any more inclined to fulfil its intended purpose.

 

I have a battery which was fitted to a working vehicle until about 2 weeks ago, the battery was working when it was removed but in transit it fall over and quite a bit of acid leaked out, I plan to top it back up and try and re-use it, does anyone have any advice on whether this is a good idea? I was going to top it up with de-ionised water unless anyone knows where I might be able to procure sulphuric acid without going on some kind of government register?

 

 

[Alexg]

I have, just jump started it after 18 months dormant and left it running to charge a bit. Then drove to work, stuck it on a battery charger. Battery charged and worked fine after with no problems. 

[cobblers]

It'll never be anything like right but it might get you by for a while.

 

If you have a "smart" battery charger then you'll struggle getting any juice into it at all (you can trick it by putting it in parallel with a good battery, connecting the charger and then disconnecting the good battery after about an hour)

 

Ideally be gentle with it and trickle charge it if you can - a sidelight bulb in series with the battery will limit the current fairly well at a push, however If the voltage just flies up to 14+ as soon as you connect the charger then you might as well just bin it straight away.

[CortinaDave]

Well, I've taken it off and stuck it on the trickle charger. It's reading that its accepting a charge at least so that's a positive sign. It's one of those automatic jobbies that cuts off if it reaches fully charged so ill leave it on overnight and see what the state of play is in the morning. Fingers crossed.

[CortinaDave]

It took a full 12 hour charge before flipping to "ready" on the battery charger.

 

Bunged it in the diesel Focus this morning and it started it immediately, so looks like it might be ok.

 

Date stamped 2002 which means it was the original battery on that 406 HDi I stole it from when it got weighed in.. and has outlasted the car.

 

11 years seems bloody old for a battery to me, so I'm amazed its still working for the moment... Especially after lying totally dead for so long.