How long will a charged car battery last for?

LadyMorticia

DH was meant to go and pick up a friend this afternoon but when he went to start the car nothing electrical would work. He couldn't open it electronically, it wouldn't start, the radio wouldn't work, nothing.

Believing it to be a dead battery (we have no idea how the battery drained. His dad was the last person to use it and swore he didn't leave the lights on etc. Probably just one of those things!) he contacted his dad and they did a jump start or whatever it's called on the battery and it's currently charging up.

How long will a charged car battery last for? I know that new batteries can last up to 5 years but what about ones that are being re-charged? DH needs to go out tonight at 5:45pm and the battery started charging at 1:15pm and the car is a Vauxhall Signum Elegance.

Thank you.

WTFH

How is he charging it?

The best way to kick some life into it after using jump leads is to take it for a "spirited" drive for half an hour. That means high revs, low gears and using minimum electrics - i.e. Heater/AC/rear window/heated seats all OFF.

It should then be OK for tonight and if the journey tonight is reasonably long, that will get it back up to a reasonable charge for the future.

goonarmy

LadyMorticia wrote: »

DH was meant to go and pick up a friend this afternoon but when he went to start the car nothing electrical would work. He couldn't open it electronically, it wouldn't start, the radio wouldn't work, nothing.

Believing it to be a dead battery (we have no idea how the battery drained. His dad was the last person to use it and swore he didn't leave the lights on etc. Probably just one of those things!) he contacted his dad and they did a jump start or whatever it's called on the battery and it's currently charging up.

How long will a charged car battery last for? I know that new batteries can last up to 5 years but what about ones that are being re-charged? DH needs to go out tonight at 5:45pm and the battery started charging at 1:15pm and the car is a Vauxhall Signum Elegance.

Thank you.

Think your misunderstanding a jump start. A jump gives the starter motor enough juice to start the car. If its a diesel it "should" run without battery after this. Petrols need electric to run...all this is irrelevant. The car starts ie engine running and the alternater turns. This charges the battery. A 20 min drive will probbaly charge it enough to start again. Drive it longer though. You might have a drain and either way a new battery will be needed soon

cajef

Depends whether the battery is good, if it will not hold a charge a new one is the only answer.

LadyMorticia

WTFH wrote: »

How is he charging it?

The best way to kick some life into it after using jump leads is to take it for a "spirited" drive for half an hour. That means high revs, low gears and using minimum electrics - i.e. Heater/AC/rear window/heated seats all OFF.

It should then be OK for tonight and if the journey tonight is reasonably long, that will get it back up to a reasonable charge for the future.

He's using a battery charging unit thingymawotzit.

The journey tonight is about 75 miles.

Thank you for all of the replies. I don't know anything about this type of thing!

forgotmyname

If its a modern car with central locking and alarms/immobilisers then there will always be a small drain on the battery.

It should be put on charge every few weeks to keep it charged up.

A battery left in a dead state will deteriorate. The cells inside will fur up and reduce its capacity when recharged.

How long to charge depends on the battery capacity and the charger. A good 8 hours is a must and because its been dead i would leave it on charge for at least 24 hours.

No less than 8 though.

Gloomendoom

goonarmy wrote: »

Think your misunderstanding a jump start. A jump gives the starter motor enough juice to start the car. If its a diesel it "should" run without battery after this. Petrols need electric to run...

So do most diesels these days.

colino

If the weather is anything like it is here, and as unfortunately the factors is now shut, this is one of the few times I'd use Halfords and get a battery before embarking on a 75 mile journey. If it's out of character for the battery to run low so quickly, it sounds like its about to fail. Unfortunately modern batteries, instead of petering out, tend to fail pretty quickly and in the middle of winter you really don't want stuck at the side of the road.

reeac

forgotmyname wrote: »

If its a modern car with central locking and alarms/immobilisers then there will always be a small drain on the battery.

It should be put on charge every few weeks to keep it charged up.

I have a car with an 11 year old battery and another with an 8 year old battery. Neither has ever need charging from an external source.

AndyPK

If the battery is good, the battery should remain charged for nearly 1 month without the car being used.

Yeah I would get one on order.

e.g
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=151182329534&ssPageName=ADME:B:SS:GB:3160

spacey2012

I would go out and start it up, give it a run for twenty minutes around 1500 rpm. With nothing turned on including the heater, well perhaps on real low
If it fails to start back up, it has had it.
A twenty minute dry tickover run at 40 AMPH is better than slow charging for 3 or 4 hours.