Patent ID: 8344694

Claim:
A battery management circuit, comprising: a plurality of battery cells coupled in series, each battery cell having a parameter; and a magnetic device comprising a plurality of windings and operable for performing the steps of: selecting, from the plurality of battery cells, a first battery cell whose parameter has a value larger than values of the parameters of multiple battery cells in the plurality of battery cells, the first battery cell having a first terminal coupled to a polarity-marked terminal of a first winding of the plurality of windings; selecting, from the plurality of battery cells, a second battery cell that has a second terminal coupled to a polarity-marked terminal of a second winding of the plurality of windings, the second terminal having a polarity different from the first terminal of the first battery cell; storing energy transferred from the first battery cell via the first winding; and releasing the stored energy to the second battery cell via the second winding, wherein the first winding is coupled in parallel with each battery cell of the plurality of battery cells via a plurality of switches, the second winding is coupled in parallel with each battery cell of the plurality of battery cells via the plurality of switches, the parameter of the first battery cell has a maximal value in values of the parameters of the plurality of battery cells, and the parameter of the second battery cell has a minimal value in the values of the parameters of the plurality of battery cells.