Battery balancing with resonant converter

The present document relates to the charging of rechargeable batteries. In particular, the present document relates to the charging of battery stacks comprising a plurality of battery cells or storage cells. A system (120) configured to charge a first subset of storage cells (102) from a storage (100) comprising a serial arrangement of storage cells (101, 102, 103) is described. The system (120) comprises a driver circuit (124) configured to generate an AC voltage comprising a frequency component at an AC frequency (402) from an electric energy source at a DC voltage. Furthermore, the system (120) comprises a first resonance circuit (125) configured to amplify and/or attenuate the AC voltage as a function of the AC frequency (402), to yield a modified AC voltage. In addition, the system (120) comprises a first rectifying unit (121) configured to generate a modified DC voltage from the modified AC voltage, and configured to provide electric energy at the modified DC voltage to the first subset of storage cells (102).