Battery in luggage compartment behind side trim panel
WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.
Remove side trim panel.
Follow instructions for disconnecting and connecting battery.
Disconnect and cover battery negative lead.
Release front side trim panel partly and fold forward.