superb flat battery

[john hames]

hi

car is about 5 years old so when battery went flat in cold weather i replaced it , it only lasted about one week , i called out auto electrician who said it was charging ok and no leakage to earth showing he said the new battery may not be a good enough quality so i bought a better quality one , which seemed ok but failed again after about ten days, i also noticed that the locking system keeps clicking whilst driving and wondered if there is a link to the problem the car has only done 44,000 miles , i normally change the car after about three yrs and am tempted to do so as i fear it could be a hard fault to find, any help appreciated

[Caspian]

hi

car is about 5 years old so when battery went flat in cold weather i replaced it , it only lasted about one week , i called out auto electrician who said it was charging ok and no leakage to earth showing he said the new battery may not be a good enough quality so i bought a better quality one , which seemed ok but failed again after about ten days, i also noticed that the locking system keeps clicking whilst driving and wondered if there is a link to the problem the car has only done 44,000 miles , i normally change the car after about three yrs and am tempted to do so as i fear it could be a hard fault to find, any help appreciated

There are lots of circuits in a modern car that are still switched on when the ignition is off and can take more current than they should if they are faulty.

If the clicking is relevant, and I don't know if it is without an electrical check, there might be a short in one of the lock mechanisms.

Also check that the boot light is turning off when the boot is closed. If it doesn't, that will drain a battery.

Another possible fault that can cause batteries to discharge very quickly is a faulty diode pack in the alternator charging circuit. This will allow the battery to slowly discharge back through the alternator. Again an electrical check would be in order.

Whatever, best of luck getting it sorted.

[john hames]

There are lots of circuits in a modern car that are still switched on when the ignition is off and can take more current than they should if they are faulty.

If the clicking is relevant, and I don't know if it is without an electrical check, there might be a short in one of the lock mechanisms.

Also check that the boot light is turning off when the boot is closed. If it doesn't, that will drain a battery.

Another possible fault that can cause batteries to discharge very quickly is a faulty diode pack in the alternator charging circuit. This will allow the battery to slowly discharge back through the alternator. Again an electrical check would be in order.

Whatever, best of luck getting it sorted.

thanks Caspian will try your suggestions

Edited 18 December, 2010 by john hames