If the capacity variation is greater than a pre-stored value, the SOC converted from Qmin sometimes cannot recover to a control center value. In such a case, inconveniences including the continuation of an event where the HVECU cannot output a command to stop the charging are prevented by computing an apparatus SOC and reporting the SOC to the HVECU. The apparent SOC is computed by increasing the value of SOC in accordance with the magnitude of the capacity variation. The thus-computed apparent SOC is reported to the HVECU by the battery ECU, so that it can be determined that the control center value has been exceeded. Thus, it becomes possible to provide battery control apparatus, method and program and a battery control system for a battery pack which are capable of controlling the charging/discharging of the battery pack with an improved accuracy despite capacity variation.