Disclosed is a battery having an internally integrated voltage converter module. The battery includes at least one electrochemical cell having an internal bore, a voltage converter module electrically coupled to the at least one electrochemical cell and disposed within a portion of the internal bore, the voltage converter configured to convert a first voltage produced by the at least one electrochemical cell into a second, different voltage, a set of terminals being electrically coupled to the voltage converter, and a bypass circuit coupled between one of the terminals of the set of terminals and the at least one electrochemical cell to direct charging current applied from an external source to the at least one electrochemical cell.