2006 530i - High Battery Drain

It is most unlikely that two batteries would fail. It is much more likely that there is a short somewhere that is causing excessive battery drain.

The old fashioned way to check would be to disconnect the battery. If there is a spark on reconnection, there must be a short somewhere. You can also measure the current with a VOM. The current with every thing off (you cannot actually cut every thing off) should lie in the milliamp range.

On a new car, it is the dealership's job to find it. Wish them luck; these things can be hard to locate.

Jim

Good points. Further, you don't say where you're located, but if your state has "lemon laws," you may want to remind the dealer about it....

Not necessarily - some electronics could have a high initial current.

That's the reliable way. However, allow some time for things to settle down - perhaps 20 minutes or so, as certain devices remain powered for some time after switch off.

Had this same problem...it's possible your stereo or another accessory was wired directly to your battery, and thus drains it while the car is not running.

Dave Plowman (News) wrote:

If that is the way that whomever connected this equipment to your car, you really ought to complain loudly about their workmanship. Jim

It's quite common for external power amps to be connected 'direct' to the battery - but go into standby mode when no signal is present. Of course all these few milliamps here and milliamps there add up. I think I remember reading somewhere that about 2 weeks is the maximum a modern car can be left without running the engine before the battery goes flat.

Thanks to all that took time to reply. Car is at the dealership today.

Will try and follow up.

This is my 4th BMW and the first time I've had a major issue with a new one.