A battery management apparatus, comprising: a first battery which is connected to a driving body which is supplied with power to be driven and supplies power to drive the driving body ; a second battery which is connected to the first battery to supply power to charge the first battery or is connected to the driving body to supply power to drive the driving body ; a control unit configured to control at least one of electric energy which is supplied to the driving body from the first battery and electric energy which is supplied to the first battery from the second battery , and configured to measure the output amount of the second battery ; and a switch unit which is controlled by the control unit and connects at least two of the driving body , the first battery , the second battery and the control unit with each other, wherein an output density of the second battery is lower than an output density of the first battery , characterised in that when the output amount in kWh of the second battery measured by the control unit exceeds a predetermined allowable output range, the control unit is configured to control to drive the driving body through the first battery , and the switching unit is configured to electrically disconnect the second battery from the driving body , and when the output amount in kWh of the second battery measured by the control unit does not reach the predetermined allowable output range, the control unit is configured to control to drive the driving body through the first battery , and the switching unit is configured to electrically disconnect the second battery from the driving body . a first battery which is connected to a driving body which is supplied with power to be driven and supplies power to drive the driving body ; a second battery which is connected to the first battery to supply power to charge the first battery or is connected to the driving body to supply power to drive the driving body ; a control unit configured to control at least one of electric energy which is supplied to the driving body from the first battery and electric energy which is supplied to the first battery from the second battery , and configured to measure the output amount of the second battery ; and a switch unit which is controlled by the control unit and connects at least two of the driving body , the first battery , the second battery and the control unit with each other, wherein an output density of the second battery is lower than an output density of the first battery , characterised in that when the output amount in kWh of the second battery measured by the control unit exceeds a predetermined allowable output range, the control unit is configured to control to drive the driving body through the first battery , and the switching unit is configured to electrically disconnect the second battery from the driving body , and when the output amount in kWh of the second battery measured by the control unit does not reach the predetermined allowable output range, the control unit is configured to control to drive the driving body through the first battery , and the switching unit is configured to electrically disconnect the second battery from the driving body . <EOS>