System and method for balancing voltage of individual battery cells within a battery pack

A method for actively balancing charge of a battery pack, comprising:

• discharging a plurality of battery cells via a first current path during a second battery discharge cycle;
• providing charge to a first battery cell via a first flyback transformer during said second battery discharge cycle, said flyback transformer in a second current path;
• providing charge to a second battery cell via a second flyback transformer during said second battery discharge cycle, said second flyback transformer in said second current path, said charge provided to said second battery cell by providing charge to said second flyback transformer at a different timing than charge provided to said first flyback transformer;
• and
• controlling a net current flow in the secondary current path to zero while providing charge to said first and second battery cells.

A system for actively balancing battery cells of a battery pack, comprising:

• a plurality of battery cells;
• a first current path for charging and discharging said plurality of battery cells external said battery pack;
• a second current path for charging battery cells during a battery pack discharge cycle;
• and
• a controller, said controller including instructions for supplying a first charge to a first battery cell via a first flyback transformer and draining charge from a second battery cell via switching a secondary side of a second flyback transformer to a low side of the second battery cell, said first and second flyback transformers in said second current path.