1999 corsa - flat battery

[psyjrobe]

I've had to have my car jump started by the RAC twice today. I'm happy to buy and fit a new battery tomorrow but I'm worried this may not solve the problem. This morning, I had the car jump started at a friends house - it had been fine the previous day and I hadn't left the lights on or anything. After that, I drove 40 miles and went into work for about 5 hours. By that time, the battery had drained and I had to call the RAC out again.

I'm assuming that tomorrow morning the battery will be flat again which means I won't be able to drive out and get the battery tested. I don't have home start with the RAC so they won't come to my house. I'm also a student and none of my friends have jump leads - let alone cars.

This problem has come on really suddenly. I've never had problems with the battery before. If there's an actual fault like a short circuit, would it be able to drain a fully charged battery in 5 hours?

I just wanted to see if I could get any advice because I don't want to pay for a new battery and then find the problem still occurs.

 

[ColJack]

cells may be dry? not holding a charge
alternator might be shot, not charging at all..
jump starting it does not charge the battery, it just gets the car running, if the alternator is duff then even driving 40 miles to work wouldn't charge it..
try charging the battery overnight with a charger.. if it's OK for a few days then it's the alternator..

 

[wanleg]

Halfords will check the battery for free....has the battery ever been changed since the car was new ?

If the battery is okay take the alternator off and have it checked...I'm sure some places must still recon these so check your yellow pages.

 

[Spark123]

When the car is running if you place a multimeter set to a range greater than 15v DC across the battery you should see a voltage of approximately 13.8 to 14.2v. This proves the alternator is charging.
With the engine at a standstill you should see the battery gradually drop to 12v over time.
Also it might be a good idea to take the car to a garage and get them to do a drop test on the battery - it only takes a minute but will tell what state the battery is in. Ideally the battery should be charged up before doing a drop test otherwise it will just fail. (A drop test doesn't involve dropping it btw )
The worst case scenario is something putting a drain on the battery - I have seen a newly fitted radio (incorrectly wired) do this before. I have also known the alternator to cause a drain when the engine is idle. This is getting more into the realms of an auto electrician tho.

 

[TicklyT]

Check the auxilliary drive belt - if it's slipping, the alternator output will drop, and might not be enough to charge the battery.

If it's the original battery, then at ten years old it's done very well to get this far.
In my experience modern batteries do seem to fail quite suddenly and catastrophically, whereas older battery designs could be persuaded to limp on for a while with lots of TLC, a trickle charger and the occasional jump start, but that was really just delaying the inevitable.

 

[Burnerman]

If you get a new battery and the fault is still there, disconnect the battery once you have stopped the engine and see if the battery holds its charge....if it does there is likely to be an alternator fault if it goes flat once reconnected. This is because if the rectifier pack, which changes AC to DC goes open circuit, your battery will be discharged very quickly. Its worth getting hold of your radio code too! Cheers John

 

[JohnD]

if it is the original 1999 battery then it is due to be dead by now. Is it?