Energy Management

Energy Management
Energy management for the (E83) X3 SAV is taken from the E46 (3 series). The software for regulating the charging voltage is in the DME. In the event of an increased current consumption in the vehicle electrical system, the charging voltage specification can be increased. The charging voltage specification is issued by the DME via the bit serial data interface to the alternator.





E83 Bus Chart





E83 System Origin Chart

The charging voltage can be regulated as a function of the outside temperature. Thus the battery can be charged to optimum effect. At low temperatures, the charging voltage can be increased to obtain a higher capacity. At high temperatures, the charging voltage is reduced to avoid excessive gassing. The maximum charging voltage is 14.8 V.
A battery change does not have to be communicated to the DME control unit.
Energy management also features the option of load/consumer shutdown. In the event of excessive current consumption in the vehicle, the power output of the heated rear window can be reduced.