A system and method for charging a rechargeable, or secondary, battery including a series string of battery cells, a topology of charging sources that selectively provides charging current to battery cells that need to be charged, but avoids overcharging battery cells that are already charged above a predetermined voltage threshold. Based on individual cell voltage measurements, the charging current is controlled in a manner to direct charging current to the battery cell(s) needing charge until these cells are fully charged, and bypasses battery cells that are fully charged or become fully charged.