how many times did you unlock the doors? it takes 30-60 minutes for all the car electronics to go to sleep where the drain is 40mA. until then, there is a pretty big drain on the battery, depending on options, while the electronics are awake.
Past: 2001 330i ZSP/ZPP/Step
Past: 2004 S60R 6MT Sport
Past: 2007 335i 6MT ZSP/ZCW/322/655
Past: 2010 335xi ZMP/ZCW/ZPP/PPK/PE
Present: 2013 335i 6MT ZMM/ZDH/ZTP/3AG/494/508
Current Homeland Threat Level: