Patent ID: 8314592

Claim:
An energy storage unit comprising: two or more storage elements ( 2 . 2 ′) which are switched in series; a charge redistribution circuit ( 6 , 6 ′), which is installed in such a manner that a voltage of the storage element (U ELn , U ELn ′) is measured and is compared with a voltage threshold value (U THRn , U THR ,U THRn ′, U THR ′), wherein the charge redistribution circuit ( 6 , 6 ′) removes charge when the voltage threshold value (U THRn , U THR , U THRn , ′, U THR ′), is exceeded by a storage element ( 2 , 2 ′) from said storage element ( 2 , 2 ′), thus reducing its voltage (U ELn , U ELn ′), and a storage related temperature determination is conducted and the voltage threshold value (U THRn , U THR ,U THRn ′, U THR ′) is set variably in dependence on the determined temperature (T n , T), so that as the temperature (T n , T) increases, the voltage threshold value (U THRn , U THR , U THRn ′, U THR ′) is reduced; and wherein the energy storage unit is for a motor vehicle which is equipped with an electric drive or an electric hybrid drive, wherein the voltage threshold value (U THR , U THR , U THRn ′, U THR ′) is also set variably in dependence on the current operating state of the vehicle, in such a manner that the threshold value (U THRn , U THR , U THRn ′, U THR ′) is set higher for relatively brief periods of time when the storage or removal requirement is relatively high.