Patent ID: 8324862

Claim:
A charge redistribution circuit for an energy storage unit ( 1 ) with several storage elements ( 4 ) which are connected in series, the circuit comprising: two or more charge redistribution control units ( 5 ) for monitoring a voltage and redistributing a charge, and each control unit is assigned an energy sub-group ( 3 ) of a plurality of storage elements ( 4 ), wherein each of the charge redistribution control units use energy from the assigned sub-group as an energy supply, and are supplied with a voltage which is higher than the voltage of an individual storage element ( 4 ) and lower than the voltage of the energy storage unit ( 1 ), and the charge redistribution circuit ( 2 ) is established in such a manner that a voltage monitoring and—when necessary—a charge redistribution is achieved between individual storage elements ( 4 ) within the energy sub-group and wherein in order to distribute the charge among the storage elements ( 4 ), the charge redistribution control units ( 5 ) are equipped with voltage converters, internal to the sub-groups, which are assigned to the individual storage elements ( 4 ), and with a voltage converter ( 8 ) which is assigned in each case to one of the sub-groups ( 3 ) in order to redistribute the charge among the sub-groups to each other, wherein the charge redistribution is achieved in such a manner that the charge is distributed between the storage elements ( 4 ) which belong to a sub-group ( 3 ), and the charge is distributed among the energy storing sub-groups ( 3 ).