BATTERY CONTROL SYSTEM, BATTERY PACK, ELECTRONIC DEVICE AND CHARGER

• US 20140370940A1
• Filed: 02/08/2013
• Published: 12/18/2014
• Est. Priority Date: 02/29/2012
• Status: Active Grant

• Current Assignee: Envision AESC Energy Devices Ltd.
• Original Assignee: NEC Energy Devices, Ltd. (Envision Group /TX/)
• Inventors: Yoshida, Tadahiro
• Granted Patent: US 9,276,417 B2
• Time in Patent Office: Days
• US Class Current: 455/572
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: H04M 1/0262 for a battery compartment
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A plurality of battery cells (100) are connected in series to each other. A temperature measurement unit (300) measures temperatures of two or more battery cells (100). A battery control unit (400) controls charge and discharge of the battery cells (100) on the basis of the temperatures measured by the temperature measurement unit (300). In addition, when the charge of the battery cells (100) is performed or the discharge of the battery cells (100) is performed, the battery control unit (400) specifies a lowest temperature cell having the lowest temperature and a highest temperature cell having the highest temperature, on the basis of the temperatures measured by the temperature measurement unit (300). In addition, the battery control unit (400) continues the charge or discharge, as it is, when a first condition in which a temperature difference ΔT between the highest temperature cell and the lowest temperature cell is equal to or greater than a reference value T₁ is not satisfied. On the other hand, when the temperature difference ΔT satisfies the first condition, the battery control unit (400) outputs a first signal.

Claims

1. A battery control system comprising:

a temperature measurement unit that measures temperatures of two or more battery units of a plurality of battery units which are connected in series to each other; and

a battery control unit that controls charge and discharge of the battery units on the basis of the temperatures measured by the temperature measurement unit,

wherein the battery control unit

specifies a lowest temperature unit in which the temperature is lowest and a highest temperature unit in which the temperature is highest, on the basis of the temperatures measured by the temperature measurement unit, when the charge of the battery unit is performed or the discharge of the battery unit is performed,

continues the charge or the discharge as it is when a first condition in which a temperature difference between the highest temperature unit and the lowest temperature unit is equal to or greater than a reference value is not satisfied, and

outputs a first signal when the temperature difference satisfies the first condition.

2. The battery control system according to claim 1, further comprising a voltage measurement unit that measures voltages of the battery units,

wherein the battery control unit stops outputting the first signal when the first signal is output and then a voltage difference between the highest temperature unit and the lowest temperature unit becomes equal to or less than a first reference voltage value.

3. The battery control system according to claim 2, wherein the first signal includes a voltage difference signal indicating the voltage difference.

4. The battery control system according to claim 2, wherein the battery control unit outputs a second signal which is different from the first signal when the first signal is stopped and then the voltage difference is becomes equal to or less than a second reference voltage value lower than the first reference voltage value.

5. The battery control system according to claim 1, wherein the battery control unit changes the reference value of the temperature difference in the first condition on the basis of the temperatures of the battery unit.

6. The battery control system according to claim 5, wherein the reference value of the temperature difference becomes smaller as the temperature of the lowest temperature unit or the highest temperature unit becomes lower.

7. The battery control system according to claim 1, wherein the first signal includes a temperature difference signal indicating the temperature difference.

8. The battery control system according to claim 1, wherein the first signal includes a temperature signal indicating the temperature of at least one battery unit out of the lowest temperature unit and the highest temperature unit.

9. The battery control system according to claim 1, wherein the temperature measurement unit further measures a temperature of outside air, and

the first signal includes an outside air temperature signal indicating the temperature of outside air.

10. The battery control system according to claim 1, wherein the battery control unit stops outputting the first signal when the first signal is output and then the temperature difference does not satisfy the first condition.

11. The battery control system according to claim 1, wherein the temperature measurement unit measures the temperatures of:

at least one battery unit which is disposed at the outermost side; and

the battery unit which is located further inside than the at least one battery unit.

12. The battery control system according to claim 1, further comprising a load control unit, connected to the battery control unit, which receives the first signal and controls a load consuming power of the discharge,

wherein the load control unit reduces a current in the discharge when the first signal is received from the battery control unit.

13. The battery control system according to claim 12, further comprising a voltage measurement unit that measures voltages of the battery units

wherein the first signal includes a voltage difference signal indicating the voltage difference between the highest temperature unit and the lowest temperature unit,

the load control unit reduces the current until the voltage difference becomes equal to or less than the first reference voltage value, on the basis of the voltage difference signal, when the first signal is received, and

the battery control unit stops outputting the first signal when the first signal is output and then the voltage difference becomes equal to or less than the first reference voltage value.

14. The battery control system according to claim 13, wherein the battery control unit outputs a second signal which is different from the first signal when the first signal is stopped and then the voltage difference becomes equal to or less than a second reference voltage value lower than the first reference voltage value, and

the load control unit can increase the current when the second signal is received.

15. The battery control system according to claim 12, wherein the first signal includes a temperature difference signal indicating the temperature difference, and

the load control unit performs control so that the current is reduced as the temperature difference becomes larger, on the basis of the temperature difference signal, when the first signal is received.

16. The battery control system according to claim 12, wherein the first signal includes a temperature signal indicating the temperature of at least one battery unit out of the lowest temperature unit and the highest temperature unit, and

the load control unit performs control so that the current is reduced as the temperature becomes lower, when the first signal is received.

17. The battery control system according to claim 12, wherein the temperature measurement unit further measures a temperature of outside air,

the first signal includes an outside air temperature signal indicating the temperature of outside air, and

the load control unit performs control so that the current is reduced as the temperature of outside air becomes lower, when the first signal is received.

18. The battery control system according to claim 12, wherein the load control unit performs control so that the current becomes equal to or less than a present current value, when the first signal is stopped.

19. The battery control system according to claim 1, wherein the battery unit includes a lithium-ion secondary battery.

20. A battery pack comprising:

a plurality of battery units which are connected in series to each other;

a temperature measurement unit that measures temperatures of two or more battery units; and

a battery control unit that controls charge and discharge of the battery units on the basis of the temperatures measured by the temperature measurement unit,

wherein the battery control unit

specifies a lowest temperature unit in which the temperature is lowest and a highest temperature unit in which the temperature is highest, on the basis of the temperatures measured by the temperature measurement unit, when the charge of the battery unit is performed or the discharge of the battery unit is performed,

continues the charge or the discharge as it is when a first condition in which a temperature difference between the highest temperature unit and the lowest temperature unit is equal to or greater than a reference value is not satisfied, and

outputs a first signal when the temperature difference satisfies the first condition.

21. An electronic device comprising:

a battery pack including a plurality of battery units which are connected in series to each other;

a temperature measurement unit that measures temperatures of two or more battery units;

a battery control unit that controls discharge of the battery units on the basis of the temperatures measured by the temperature measurement unit;

a load that consumes power of the discharge from the battery pack; and

a load control unit, connected to the battery control unit, which controls the load,

wherein the battery control unit

specifies a lowest temperature unit in which the temperature is lowest and a highest temperature unit in which the temperature is highest, on the basis of the temperatures measured by the temperature measurement unit, when the discharge of the battery unit is performed,

continues the charge or the discharge as it is when a first condition in which a temperature difference between the highest temperature unit and the lowest temperature unit is equal to or greater than a reference value is not satisfied, and

outputs a first signal when the temperature difference satisfies the first condition, and

the load control unit reduces a current in the discharge when the first signal is received from the battery control unit.

22. The electronic device according to claim 21, further comprising a voltage measurement unit that measures voltages of the battery units,

wherein the battery control unit stops outputting the first signal when the first signal is output and then a voltage difference between the highest temperature unit and the lowest temperature unit becomes equal to or less than a first reference voltage value.

23. The electronic device according to claim 21, wherein the load includes at least one or more light-emitting units, and

the load control unit reduces the current by lowering luminance of the light-emitting unit when the first signal is received from the battery control unit.

24. The electronic device according to claim 21, wherein the load includes at least one or more arithmetic operation process units, and

the load control unit reduces the current by lowering a processing speed of the arithmetic operation process unit when the first signal is received from the battery control unit.

25. The electronic device according to claim 21, wherein the electronic device is a portable communication terminal that performs a phone call or packet communication,

the load includes a communication unit that performs the communication, and

the load control unit reduces the current by controlling the communication unit so as to restrict the phone call and perform only the packet communication when the first signal is received from the battery control unit.

26. The electronic device according to claim 21, wherein the load includes at least one or more electric drive units, and

the load control unit reduces the current by reducing the power which is supplied to the electric drive unit when the first signal is received from the battery control unit.

27. The electronic device according to claim 21, further comprising a fuel drive unit which is driven by fuel,

wherein the load is at least one or more electric drive units, and

the load control unit reduces the current by reducing a power supply amount from the battery pack to the electric drive unit and increasing a drive ratio in the fuel drive unit, when the first signal is received from the battery control unit.

28. The electronic device according to claim 21, which is connected to at least one or more power supply units other than the battery pack,

wherein the load control unit reduces a power supply amount from the battery pack to the load and increases the power supply amount from the power supply unit to the load when the first signal is received from the battery control unit.

29. The electronic device according to claim 21, wherein the load control unit monotonically reduces the current consumed in the load when the first signal is received from the battery control unit.

30. The electronic device according to claim 21, further comprising a plurality of the loads,

wherein the load control unit reduces the number of loads that presently consume the power when the first signal is received from the battery control unit.

31. A charger comprising:

a temperature measurement unit that measures temperatures of two or more battery units of a plurality of battery units which are connected in series to each other;

a battery control unit that controls charge of the battery units on the basis of the temperatures measured by the temperature measurement unit; and

a charge control unit, connected to the battery control unit, which controls a voltage and a current in the charge,

wherein the battery control unit

specifies a lowest temperature unit in which the temperature is lowest and a highest temperature unit in which the temperature is highest, on the basis of the temperatures measured by the temperature measurement unit, when the charge of the battery unit is performed,

continues the charge or the discharge as it is when a first condition in which a temperature difference between the highest temperature unit and the lowest temperature unit is equal to or greater than a reference value is not satisfied, and

outputs a first signal when the temperature difference satisfies the first condition, and

the charge control unit reduces the current in the charge when the first signal is received from the battery control unit.

32. The charger according to claim 31, further comprising a voltage measurement unit that measures voltages of the battery units,

wherein the battery control unit stops outputting the first signal when the first signal is output and then a voltage difference between the highest temperature unit and the lowest temperature unit becomes equal to or less than a first reference voltage value.