To ensure that the individual battery packs of an electric vehicle do not charge differently, the charge states of all battery packs are monitored in their most important characteristic values when charging the vehicle batteries. This function is performed by the Cell Supervisory Circuit (CSC). If individual charge curves deviate, the charge parameters for the corresponding battery pack are changed accordingly. This is also referred to as battery cell balancing. This ensures that all battery packs have identical states of charge when the charging process is completed.