Battery management apparatus and method

1. 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 which controls electric energy which is supplied between the first and second batteries in accordance with states of the first and second batteries, the control unit measuring the output amount of the second battery; and

a switch unit which is controlled by the control unit and connects the first and second batteries and the control unit with each other,

wherein, when the output amount of the second battery measured by the control unit exceeds a predetermined fixed allowable output range, the control unit controls to drive the driving body through the first battery and the switch unit electrically disconnects the second battery from the driving body,

wherein, when the output amount of the second battery measured by the control unit does not reach the predetermined allowable output range, the control unit controls to drive the driving body through the first battery and the switch unit electrically disconnects the second battery from the driving body, and

wherein a power density of the second battery is lower than a power density of the first battery.

2. The battery management apparatus of claim 1 , wherein an energy density of the first battery is lower than an energy density of the second battery.

3. The battery management apparatus of claim 2 , wherein the first battery is one or more of a lithium ion (Li-ion) battery, a nickel-metal hydride (Ni-MH) battery, and a metal air battery.

4. The battery management apparatus of claim 1 , wherein a capacity of the second battery is larger than a capacity of the first battery.

5. The battery management apparatus of claim 1 , wherein the second battery is one or more of a lithium (Li) battery, a lithium sulfur (Li—S) battery, a metal air battery, and an all solid state battery.

6. The battery management apparatus of claim 1 , wherein when a state of charge of the first battery is equal to or lower than a predetermined state of charge and the output amount of the second battery measured by the control unit is within the predetermined allowable output range, the control unit controls to supply the power of the second battery so as to drive the driving body through the power of the second battery.

7. The battery management apparatus of claim 6 , wherein the switch unit includes first and second switch units which are connected to the driving unit, and

the control unit turns off the first switch unit and turns on the second switch unit when the state of charge of the first battery is equal to or lower than the predetermined state of charge and turns off the second switch unit when the state of charge of the first battery exceeds the predetermined state of charge.

8. The battery management apparatus of claim 1 , wherein when a state of charge of the first battery is equal to or lower than a predetermined state of charge and the output amount of the second battery measured by the control unit is within the predetermined allowable output range, the control unit controls the power of the second battery so as to charge the first battery by the second battery.

9. The battery management apparatus of claim 8 , wherein the switch unit includes:

a first switch unit which is provided between the driving body and the first battery; and

a second switch unit which is provided between the first and second batteries,

when the state of charge of the first battery is equal to or lower than the predetermined state of charge, the control unit turns on the second switch unit to charge the first battery through the power of the second battery and

when the state of charge of the first battery exceeds the predetermined state of charge, the control unit turns off the second switch unit so as not to supply the power of the second battery to the first battery.

10. The battery management apparatus of claim 1 , wherein the switch unit includes:

first and second switch units which are connected to the driving unit,

when the output amount of the second battery does not get out of the predetermined allowable output range, the control unit turns off the second switch unit which is connected to the first battery, and

when the output amount of the second battery gets out of the predetermined allowable output range, the control unit turns off the first switch unit which is connected to the second battery and turns on the second switch unit which is connected to the first battery to drive the driving body through the power of the first battery.

11. A battery management method, comprising:

connecting a driving body which is supplied with power to be driven and a first battery which supplies the power to drive the driving body;

supplying power to charge the first battery or connecting a second battery which supplies power to drive the driving body with the first battery or the driving body;

connecting a control unit which controls an electric energy which is supplied between the first and second batteries according to states of the first and second batteries with the first and second batteries through a switch unit; and

controlling of power to be supplied to the driving body, and

wherein the controlling of power to be supplied to the driving body includes:

measuring the output amount of the second battery;

controlling to supply power of the first battery so as to drive the driving body through the power of the first battery and electrically disconnecting the second battery from the driving body when the measured output amount of the second battery exceeds a predetermined fixed allowable output range, and to supply power of the first battery so as to drive the driving body through the power of the first battery and electrically disconnecting the second battery from the driving body when the measured output amount of the second battery does not reach the predetermined allowable output range,

wherein a power density of the second battery is lower than a power density of the first battery.

12. The battery management method of claim 11 , wherein the controlling of power to be supplied to the driving body further includes:

calculating, by the control unit, a state of charge (SOC) of the first battery; and

comparing, by the control unit, a predetermined state of charge with the state of charge of the first battery to control the power to be supplied to the driving body.

13. The battery management method of claim 12 , wherein the controlling of power to be supplied to the driving body includes:

controlling, by the control unit, the switch unit to drive the driving body through the power of the second battery to control to supply the power of the second battery, when the state of charge of the first battery is equal to or lower than the predetermined state of charge and the output amount of the second battery measured by the control unit is within the predetermined allowable output range.

14. The battery management method of claim 13 , wherein the controlling of supplying power of the second battery, includes:

connecting first and second switch units, which are connected to the driving body, with the first and second batteries, respectively; and

turning off the first switch unit and turning on the second switch unit when the state of charge of the first battery is equal to or lower than the predetermined state of charge and turning off the second switch unit when the state of charge of the first battery exceeds the predetermined state of charge, by the control unit.

15. The battery management method of claim 12 , wherein the controlling of power to be supplied to the driving body includes: controlling power of the second battery so as to charge the first battery by the second battery when a state of charge of the first battery is equal to or lower than a predetermined state of charge and the output amount of the second battery measured by the control unit is within the predetermined allowable output range.

16. The battery management method of claim 15 , wherein the controlling of power of the second battery, includes:

providing a first switch unit between the driving body and the first battery to be connected to each other;

providing a second switch unit between the first battery and the second battery to be connected to each other; and

turning on the second switch unit to charge the first battery through power of the second battery when the state of charge of the first battery is equal to or lower than the predetermined state of charge and turning off the second switch unit so as not to supply the power of the second battery to the first battery when the state of charge of the first battery exceeds the predetermined state of charge, by the control unit.

17. The battery management method of claim 12 , wherein the controlling of supplying power of the first battery, includes:

connecting first and second switch units, which are connected to the driving body, with the second and first batteries, respectively; and

turning off the second switch unit which is connected to the first battery when the output amount of the second battery does not get out of the predetermined allowable output range, turning off the first switch unit which is connected to the second battery and turning on the second switch unit which is connected to the first battery to drive the driving body through the power of the first battery when the output amount of the second battery gets out of the predetermined allowable output range, by the control unit.