Patent ID: 8729860

Claim:
An energy storage assembly comprising: a plurality of cells connected in series, wherein the series connection of the cells is connected to a power output of the energy storage assembly; a control unit, wherein at least some of the cells connected in series are connected to the power output and the control unit by way of potential-free controlled converter and control units respectively connected in parallel, such that, during the charging, discharging and charge-reversing operations, each of the cells is operated according to the individual performance characteristics of this cell by means of selective current drains by the converter and control units and a total current flowing at the power output of the energy storage assembly is formed by a base current flowing through the series connection of the cells and by additional currents, which are drained from the individual cells depending on their capacity; and in the case of a charging operation, the control unit is configured to establish when the voltage of one of the cells approaches a cell-individual end-of-charge voltage and, in this case, the respectively assigned converter and control unit are configured to return the then superfluous energy from this cell into the overall system.