Charge Equalization Between Series-Connected Battery Cells

A method comprising:

• determining whether a battery cell should be charged or discharged based on a cell voltage of the battery cell;
• if the battery should be discharged, then discharging a first voltage of the first battery cell into an energy store by:
• controlling a first set of one or more semiconductor switches coupled to the energy store at a first node;
• controlling a second set of one or more semiconductor switches coupled to the energy store at a second node;
• and
• if the battery should be charged, then reversing the polarity of the first and second nodes to charge the first battery by controlling the first and second sets of semiconductor switches.

A system comprising:

• a first set of one or more semiconductor switches coupled to a first node and a first terminal of an energy store configured to store energy;
• a second set of one or more semiconductor switches coupled to a second node and a second terminal of the energy store, each of the first and second sets of semiconductor switches being configured to couple to a terminal of a battery cell;
• and
• a controller coupled to the first and second sets of semiconductor switches, the controller configured to:
• control a first switched connection by regulating the first set of semiconductor switches;
• and
• control a second switched connection by regulating the second set of semiconductor switches.