Hi, My name is Richard.
I have a 2002 530is, haven't had it that long, my first BMW, I do like the way it drives, but I have allready developed a problem with the battery and alternator.
I lost all functions in the car which I assumed the battery was dead. wish I was right. I replaced the battery and everything seemed to be just fine. But, about  
one day later the battery light came on. I thought to myself that buying a battery without checking the alternater was a pretty stupid move. So, I took the alternater out
and had it check and found that the regulator was bad. So I had it repaired and I reinstalled it in the car. When I started the car it seemed to be just fine, no battery light
was on. But it wasn't to long the battery went down.
I have no idea what could be wrong, I've tried everything. Hope somebody could help me out with some secret trhat I'm not doing?
Thanks