'02 A3 losing battery charge over night.

[roadsterdriver]

Hi,
My wife's A3 seems to be losing battery charge while it sits. It start OK after a long drive, but loses charge over night. I put a new battery in it. No change. Also the mechanic "ran all the tests," and came up with nothing so he installed a new starter motor. No change.

Any help would be appreciated. Thanks.

[revo_20vt]

Hello mate, have u checked if the fan is turning off after you have stopped? I think that it is a common problem for the fan not to turn off resulting in a flat battery, just a thought :approve:

[beachy]

Just a quick thought. Have you check the condition and tension of the belt from the alternator? I know its a basic idea but I have heard ones where the alternator slips and therefore does not charge all the time. Hence why on long journeys it does charge and on short journeys it does charge enough!

Hope this helps

[a8 tech]

You need to run a drain test.The networks on a3 will take at least 2 hours to drop to 0.030amps.If after this your seeing a higher drain then you need to be looking at a few common issues with a3.
1 rear washer pipe leaks onto the tailgate boot switch causing resistive circuit and a drain.
2 after market radio.
3 door lock open/closed switch.
For the battery to drain so quick i would say you have a drain of above 1.00 amp.
Make sure the radio turns off when the ignition key is remoed as the S contact may be sticking