Remove battery earth lead

WARNING: Working on 12 V vehicle electrical system.
Risk of short circuits! Risk of fire!

Make sure that no charger is connected to the jump start support point in the engine compartment.
Detach battery earth lead from battery.
With auxiliary batteries: Detach all battery earth leads from additional batteries.

Preliminary works

Deactivate the 48v ELECTRICAL SYSTEM
Disconnect all battery EARTH LEADS .

Unlock the connector (1) on the intelligent battery sensor (IBS) and disconnect it.
Loosen nut (2).
Remove the battery earth lead (3).

Courtesy of BMW OF NORTH AMERICA, INC.