After finding out about the Brake Energy Regeneration, and the fact that the alternator has a clutch, and it is disengaged much of the time, I wonder how much that plays into this problem. I wonder if in the search for efficiency and mileage, they may not have the alternater engaged enough. This explains why they may try a software update to solve the problem. The update could possibly engage the alternator for more of the time. It seems to me that in different climates, there would need to be different variations in when the software engages the alternator.
Another problem is that in cold climates, the battery output drops with the drop in temperature. Out here in the warm climates I have not had any problem with the battery and I have used the sound system, talked on the phone, with the car off, and never had a problem.
One point I would like to raise is the Angel Eye swaps. If you increase the wattage and therefore the current draw on the system, does this now make you have trouble with the battery keeping a good charge? The way it sounds to me, the lights are run by the battery only, until you coast or use the brakes.
I think the BMW has a high output alternator, I think it may need to be turned by the engine more of the time! Go figure?
