Battery Charging

Battery Charging:

If a normal or rapid charger is used to charge the battery (e.g. Bosch SL 24 90, refer to BMW Parts Service), the battery must be disconnected from the vehicle circuit and removed in order to avoid damage to paint finishes and upholstery by escaping gas.
Excessively discharged batteries could be damaged or destroyed by the very high initial current (high temperature).
When using an electronically controlled charger (e.g. Siemens VB 80), the battery can remain connected. The electronically controlled charger does not permit critical peak voltage.
An electronic charger also charges an excessively discharged battery with reduced current until a certain basic voltage is reached.
If there is any doubt regarding the suitability of the battery charger in the workshop, refer to Service Information 61 09 88 (900)


CAUTION: Always first measure open-circuit voltage before charging a battery installed in the vehicle. If the voltage is 10 V or less, there is a possibility that one or more cells are faulty or that the battery as a whole is already pre-damaged. In this case it is always necessary to remove the battery, as escaping gas while charging could damage interior equipment. Attempt to regenerate faulty cells with low charging current.


For safety sake, open seal plugs on each individual cell.