Necessary preliminary work:
Fold back cover (1).
Release nut underneath. Remove positive battery cable from positive battery connection point.
Release battery positive lead (1) from retainers (2).
Release clamp (1).
Release clamps (2).
Unlock tab (3) in direction of arrow. Remove top part of cable holder toward the top and uncover wiring harnesses.
Unfasten nut.
Disconnect positive battery cable (2) from starter motor.
Remove protective cap (2) and release nut underneath.
Remove battery positive lead from alternator and feed out.
NOTE: Reassemble the vehicle.
Check stored fault messages.
Delete fault memory.
BMW X3 Service & Repair Manual > Troubleshooting: Notes for disconnecting and connecting battery
Observe SAFETY INFORMATIONS FOR HANDLING VEHICLE BATTERY .
Before disconnecting battery:
Turn off the ignition and other electrical loads/consumers to prevent sparking when reconnecting.
NOTE:
If the ignition is not turned off when the battery is disconnected, fault memories
may be set in so ...