[E90Fleet]

The car is designed to be charged via the under hood connectors.
Dealers connect there every time the car goes on their diagnostics system.

Show them your owners manual (or download one from BMWUSA.com)
Page 265 of the 2012 7 Series manual states it is only safe to recharge the battery from the under hood terminals.


If you remove the battery you will have to reset soime things like the power windows/sunroof ect ect.

If you really want to disconnect the battery:
Be careful and observe normal battery safety procedures.
You first disconnect the black ground cable, then open a little "door" on the red plastic part to find the positive terminal bold and then disconnect that.
Then you have to get the red plastic part off the battery. Its usually clipped onto the sides of the battery.
Then find the screw holding the bottom of the battery onto the car via a clip and remove it. Now move the red tray out teh way and remove the battery ( usually not easy due to weight and little room)