Bayerische Motoren Werke Aktiengesellschaft

Alexander Mai

Joachim Froeschl

Sebastian Reischl

Klaus Wandel

Tobias Handschuh

Andreas Weisshuhn

Aleksandar Otasevic

A device for balancing an energy accumulator, especially an energy accumulator in an on-board power supply system of a motor vehicle, is provided. The energy accumulator is formed by a cell assembly of a serial connection of a plurality of cell groups, respective balancing circuits being connected to voltage connections of respective cell groups and comprising a discharge resistor. The discharge resistor of a respective balancing circuit has a temperature-dependent resistance characteristic, and the discharge resistors of at least some of the balancing circuits are thermally intercoupled.

Device for balancing an energy accumulator

A suitable electrical system for a motor vehicle is provided, which system requires a voltage supply during a possible towing-away operation. A voltage-supply control device recognizes the provision of an external voltage supply, in particular by way of a towing vehicle for the motor vehicle, and controls the voltage supply in the motor vehicle in such a manner that only one or more subsystems of the entire electrical system of the motor vehicle are supplied with voltage.

Electrical system of a vehicle, provided for the towing away of the same

The amount of energy actually available in an energy storage module having a plurality of individual storage elements connected in series is determined. An upper and/or a lower limit voltage for the energy storage module is determined dynamically. During a charging operation of the energy storage module, in the event that a maximally permissible upper cell voltage is reached on at least one storage cell, the upper limit voltage of the energy storage module is determined by summing all cell voltages of all storage elements existing at that point-in-time. During a discharging operation, if a minimally permissible lower cell voltage is reached on at least one storage element, the lower limit voltage is determined by summing all cell voltages existing at that point-in-time. The actually available amount of energy is computed as a function of the determined limit voltage or voltages and of the determined actual storage capacity.

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Munich, Germany

Alexander Mai