Device and method for the redundant determination of a battery current flowing through the poles of a battery

A device comprises a battery having a multiplicity of battery cells and a sensor system for the redundant determination of a battery current flowing through the poles of the battery. The sensor system comprises a current measuring device for detecting the battery current and providing a current measurement value. Furthermore, the device comprises a voltage measuring device for separately detecting a variation with time of the single-cell voltage of at least one battery cell and providing at least one variation with time of a voltage measurement value. Furthermore, the device comprises an evaluating unit which is configured for determining the battery current from the at least one variation with time of the voltage measurement value, providing a corresponding current value and comparing the current value with the current measurement value.