been having some probs with the battery fully discharging overnight...tried a variety of things think i sorted it. my question is should the battery on my '01 X5 3.0 loose voltage if left standing over a couple of days... it seems to be shutting down as it should but i have measured a volt drop 12.22 to 11.97 volts on the battery. the battery was new not bmw but bosch 100ah but has had at least one total discharge that i am aware of (maybe two or three while the garage was looking at it). am i getting concerned for no reason any help would be appreciated