'04 545i battery drain issue

[MarkiMark14]

Hey guys! New to the forum, brought here by a troublesome 545i I purchased not too long ago.

Anyways, when I purchased the vehicle, if not driven every day it would be dead. Silly me thinking it would just be a battery replaced the old battery and registered the new one.

Helped the issue for a bit but over time it's gotten worse. I even bought a trickle charger to try and put a band aid over the whole issue and that did no help whatsoever.

I hear this is a common issue? Wondering what a common fix is for this of there is one. At this point if the car sits more than a few hours after a drive it won't turn on.

[daw300]

Replace the alternator that should fix the problem

[jclausen]

Well with out doing a draw test then pulling fuses one by one while watching the multimeter to see when the draw drops to normal you won't know anything. You can check your alternator first before replacing.