Originally Posted by ENINTY
Back in the day when batteries were not sealed, they'd ship them "dry" and the parts store would fill up the battery with electrolite and the battery had enough charge built up to get the car started, or the parts store would fast charge it for a few mintues before that handed it over to you. Being that we're talking a BMW E90, it not suprising a battery with 12V on it wouldn't start a 12V car...
12 volt systems arent actually 12 volt systems-in fact a fully charged battery is over 12.6 volts. So at 12 volts the battery is pretty far from fully charged. 12v in a battery SHOULD start the car but it all depends where the CCA's were at-it seems as though your battery was pretty discharged-i would have returned it to the dealer if its an OEM battery and got a new one as ive NEVER had a brand new battery OEM off the shelf at work be at 12v or even less than 12.4 volts.