bad earth

If it was so flat that it stopped the car from running how would it recharge itself from just sitting?

And I'd have thought that it would take more of a current to start it than to keep it ticking over. Sometimes when I wasn't running a fan belt, if the batt was flat and you switched off the engine you'd need to bump start it because there wasn't enough battery to turn the starter. But if you bump started it it ran for another 20-30mins.

Doesn't sound like anyting to do with the battery to me.

[Edited on 17-05-2009 by alan-g-w]

Wrong. It may hold enough charge to start the car but not enough to keep it running, if you left it idleing with all the electrics running it would stop preety quick.

If that was the case the car wouldn't even start in the first place.

As above, the cells in the battery may have been buggered if it actually got to flat, meaning that no matter how good your charging circuit is the battery wont hold the charge. Try and get yourself down to a halfords as they do free battery health checks.

Can you find out the voltage across the battery? When the car is running and when its not. It could be a fucked battery.

Is there a fan belt on it... I'd assume you would know that but that's what the batery light always reminds me of. Mine used to throw belts off like no-one's business.

normally alternator fault mate.

you checked the connections on the alternator and also the starter loom?

they definately earthed properly? to me it sounds like there not

hi all, i have a 20xe corsa and the battery light on the dash is on! the car will start and drive for a mile or so and then cuts out with a completely flat battery, however if you then leave the car for half or so it starts again fine without charging the battery :boggle:! ive replaced the starter loom and it has a brand new starter and alternator which is charging fine with the engine running! can anyone shed some light on this problem for me, thanks!