Do I need a new battery?

DanFriend

Hello everyone. My car has been sitting idle in a barn for nearly a year ; once its up and running will the battery hold its charge or do I need a new one? It was a cheap Halfords variety and I didn't know to disconnect it. Thanks for your help.

bertiewhite

Only one way to find out.......

konark

Battery will be flat, you'll need to disconnect it to charge it.

DanFriend

Thanks you two. Can't I just jump start it and charge the battery while the engine is running?

AdrianC

DanFriend wrote: »

Can't I just jump start it and charge the battery while the engine is running?

You can try.

What car are we talking about? Is there all the usual modern gubbins drawing current all the time - remote locking, alarm, clock, radio/ecu memories - or is it nice and simple with nothing drawing current?

If the latter, it may well be fine. I leave my old Landy for months on end untouched, and it just fires straight up, because it has absolutely zero using current when the ignition's off. Not even a clock or radio memory.

If there's even as much as a stereo and clock, your battery will be as flat as a flat thing. Lead-acid batteries REALLY don't like that, and will be permanently damaged. It might hold a charge, but its capacity will definitely be impaired, and it could well leave you stranded just when you least need it.

Two seconds with a multimeter will give you a good guess.

DanFriend

Thank you Adrian, thought as much. Straight to Halfords.

Ebe_Scrooge

DanFriend wrote: »

Thank you Adrian, thought as much. Straight to Halfords.

Or straight to CarParts4Less.co.uk where you'll get the same battery for much less money - you'll have the choice of a budget brand or several "named" brands, whichever is your preference. No, I don't work for them, just been a satisfied customer for many years.

As has already been said, you may be lucky and find that once charged, the existing battery is OK. But as AdrianC correctly says, car batteries really don't like being fully discharged, so you may well find it only holds a partial charge - not ideal during the winter, when a battery takes more of a thrashing than usual.

< As an aside, that's why these "leisure batteries" for caravans etc. are so much more expensive - they can cope with full discharges >

Norman_Castle

DanFriend wrote: »

Thanks you two. Can't I just jump start it and charge the battery while the engine is running?

I used a battery charger on a battery from a car which had been unused for over a year. The charger repeatedly overheated and cut out. It took many hours of charging over a few days to charge the battery. From memory using a car with a battery which is very flat can damage the alternator.


Once charged the battery was fine during the following month for the irregular use it got.

DanFriend

More good advice, will do that.

coffeehound

Norman_Castle wrote: »

I used a battery charger on a battery from a car which had been unused for over a year. The charger repeatedly overheated and cut out. It took many hours of charging over a few days to charge the battery. From memory using a car with a battery which is very flat can damage the alternator

Interesting. Is that due to internal plates distorting and making contact?

DanFriend

Just found a compatible battery with good reviews on Amazon for £38, delivered next day if you have Prime.