E39 battery drain

[kiethton]

Within 2 days of putting the BMW reset and recharged battery in its died again....

Likely cause?

[kiethton]

18 months, had it back from BMW this weekend apparently fixed after the RAC said it was fubar - still under warranty

[kiethton]

This was my thought, however...the fan seems to behave itself?

One thing I have noticed was that the night before it went flat (every time it's done it) I've heard a car alarm...starting to think it may have been mine...

Would a hedgehog cause this?

If I was to get a new one is it best to go OEM or pattern? - £20 vs. £90

[kiethton]

Thanks for that, my car has all of those....think I need a multimeter and trickle charger!