US Patent 10263297 Control system for a battery

A method and apparatus for operating a battery system. The apparatus comprises a housing, a plurality of battery cells, and a bypass circuit. The plurality of battery cells is connected in a series circuit within the housing. The plurality of battery cells is configured to supply a total voltage output. The bypass circuit is configured to determine whether a voltage output from a battery cell in the plurality of battery cells has fallen below a selected threshold. The bypass circuit is further configured to bypass the battery cell in the series circuit in response to a determination that the voltage output from the battery cell has fallen below the selected threshold.