Sportrak battery goes flat if parked up for couple of weeks


Help! Help

I have a 1993, J Reg, Daihatsu Sportrak 1.6 4x4. Since I bought it 6 years ago, the battery keeps going flat if its parked up for a couple of weeks. After my fifth new battery, I realised it can not be the battery at fault. For the past 3 years I have been disconnecting the battery earth lead when I park. This is an obvious inconvenience.

The local auto electrician has disconnected the immobiliser, replaced the alternator charging diodes, new fan belt etc.

Last week he disconnected the battery earth and put his digital tester in line with that lead and the battery negative post. The reading was negligible.

There is a radio in the vehicle. It does not go through the ignition switch, but it is never switched on. Glove box, interior and all other lights are off.

The battery is a smaller unit than most other cars.

Any ideas on how to address this problem would be more than welcome?!!


Your electrician seems incompetent, it should have been a current test on the positive terminal, this will show how much curent is drawn with the vehicle stationary.

Disconnect the battery positive, insert a current testing meter between the post and the lead, this will show current drain. Move to the fuse box, remove one fuse at a time and watch the meter, if the current drain stops or reduces you have one of the circuits draining your battery. Continue with all the fuses, and identify all current draining circuits.

Having isolated these circuits you can identify what they feed, then check back to each item on that circuit. Please note that alarms draw considerable current and that many radios have a constant live to retain the memory, this live may not be covered by the main fuse box, but could have an inline fuse in the memory supply wire. Check all items not covered by fused circuits, this includes the starter motor, and any additional fitments, dirty starters leak electricity slightly, and benefit from a simple internal clean to rid them of carbon deposits and wet dirt.

This is a long winded process, but far cheapeer than going to an auto electrician.