Grouped cells state of charge calculation device, grouped cells state of charge calculation method, program, and grouped cells soc display device

The SOC output from each battery cell is input to a maximum SOC calculation unit (3) and a minimum SOC calculation unit (4), and an SOCmax and an SOCmin are calculated based thereon. The SOCmax and SOCmin are input to an SOC table or function (5) and a single fixed, representative SOC is created and output. At this time, the representative SOC created by SOC table or function (5) is, for example, a value near SOCmax in the vicinity of a full charge for the group of cells or is a value near SOCmin in the vicinity of depleted charge. Thus, a representative SOC for a group of cells can be determined in the operating state while taking into account variation in the SOC for each battery cell.