A battery control apparatus of this invention comprises charge detecting circuit for detecting change of charge of a battery based on current of the battery, first residual charge amount detecting circuit coupled to the charge detecting circuit for detecting a first residual charge amount of the battery by compensating a predetermined reference residual charge amount based on the detected result of the change of charge of the battery. The battery control apparatus further comprises second residual charge amount detecting circuit for detecting a second residual charge amount of the battery based on al terminal voltage of the battery and reference residual charge amount updating circuit for updating the reference residual charge amount by detected result of the second residual charge amount of the battery, wherein the second residual charge amount of the battery is detected at a predetermined timing where the current of the battery is zero or almost zero.