Bayerische Motoren Werke Aktiengesellschaft

Philipp Riemann

Armin Friegel

Benno Schweiger

Bernhard Kreppold

An energy storage device has a plurality of storage cells. In this case, each storage cell is designed to be connected in an offline operation and separately from the remaining storage cells to a device for determining the capacitance of the energy storage device.

Energy storage device and device and method for determining a capacitance of an energy storage device

A method determines a capacity of a battery cell of a high-voltage battery of a motor vehicle. The method receives at least three open-circuit voltage values of the battery cell; determines state of charge values of the battery cell from the open-circuit voltage values on the basis of a predetermined open-circuit voltage curve; forms at least two pairs of values by combining in each case two of the at least three open-circuit voltage values; determines respective charge throughput values of the battery cell which are specific to the pairs of values by integrating a measured current of the battery cell over a period between two measuring times of the associated open-circuit voltage values; determines respective capacity raw values which are specific to the pairs of values on the basis of the associated charge throughput value which is specific to the pairs of values and the associated state of charge values which are specific to the pairs of values; and determines the capacity on the basis of the at least two capacity raw values which are specific to the pairs of values.

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Munich, Germany

Philipp Riemann