BATTERY PACK AND METHOD OF CONTROLLING THE SAME

• US 20130106355A1
• Filed: 08/10/2012
• Published: 05/02/2013
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: KIM, Bong-Young, Kim, Young-Ho
• Granted Patent: US 9,166,414 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: G01R 31/387 Determining ampere-hour charge capacity or SoC
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack including a plurality of battery cell groups including a first battery cell group and a second battery cell group, a first switch that is connected to the first battery cell group, a second switch that is connected to the second battery cell group, and a controller configured to selectively control charging and discharging operations of the first battery cell group and the second battery cell group using the first switch and the second switch.

Claims

1. A battery pack, comprising:

a plurality of battery cell groups including a first battery cell group and a second battery cell group;

a first switch connected to the first battery cell group;

a second switch connected to the second battery cell group; and

a controller configured to selectively control charging and discharging operations of the first battery cell group and the second battery cell group using the first switch and the second switch.

2. The battery pack as claimed in claim 1, wherein the first battery cell group and the second battery cell group have different capacitances.

3. The battery pack as claimed in claim 1, further comprising a current adjustment unit connected to one of the first battery cell group and the second battery cell group.

4. The battery pack as claimed in claim 3, wherein the current adjustment unit includes a positive temperature coefficient (PTC) element.

5. The battery pack as claimed in claim 1, wherein, when a capacitance of the first battery cell group is greater than a capacitance of the second battery cell group, the controller controls the charging and discharging operations of the first battery cell group first.

6. The battery pack as claimed in claim 1, further comprising, when a capacitance of the first battery cell group is greater than a capacitance of the second battery cell group:

a PTC element connected between the second battery cell group and the second switch; and

a diode connected in parallel to the PTC element and of which an anode is connected to a positive side of the second battery cell group and of which a cathode is connected to the second switch.

7. The battery pack as claimed in claim 1, further comprising:

a first analog front end (AFE) circuit configured to detect a remaining battery amount of the first battery cell group; and

a second AFE circuit configured to detect a remaining battery amount of the second battery cell group,

wherein the controller controls the charging and discharging operations of the first battery cell group and the second battery cell group based on the remaining battery amount of the first battery cell group and the remaining battery amount of the second battery cell group obtained by the first AFE circuit and the second AFE circuit, respectively.

8. The battery pack as claimed in claim 7, wherein, if a capacitance of the first battery cell group is greater than a capacitance of the second battery cell group, when a discharging operation is performed, the controller discharges the first battery cell group by turning on the first switch and turning off the second switch, and when the remaining battery amount of the first battery cell group detected by the first AFE circuit is less than a first threshold value, the controller discharges the second battery cell group by turning off the first switch and turning on the second switch.

9. The battery pack as claimed in claim 7, wherein, if a capacitance of the first battery cell group is greater than a capacitance of the second battery cell group, when a charging operation is performed, the controller charges the first battery cell group by turning on the first switch and turning off the second switch, and when charging of the first battery cell group is completed, the controller charges the second battery cell group by turning off the first switch and turning on the second switch.

10. The battery pack as claimed in claim 9, wherein, when the first battery cell group is charged, if discharging of the first battery cell group is needed, the controller discharges the first battery cell group.

11. The battery pack as claimed in claim 9, wherein, when the second battery cell group is charged, if discharging is needed, the controller discharges the first battery cell group by turning off the second switch and turning on the first switch.

12. The battery pack as claimed in claim 11, wherein, when the second battery cell group is charged, if discharging is needed, the controller discharges the first battery cell group by turning off the second switch and turning on the first switch before the controller discharges the second battery cells group by turning on the second switch and turning off the first switch.

13. A battery protection circuit, comprising:

a first switch connected to a first battery cell group;

a second switch connected to a second battery cell group having a capacitance less than a capacitance of the first battery cell group;

a current limiter connected between a positive side of the second battery cell group and the second switch;

a diode connected in parallel to the current limiter; and

a controller that controls charging and discharging operations of the first battery cell group first.

14. A method of controlling a battery pack, the method comprising:

turning on a first switch connected to a first battery cell group;

turning off a second switch connected to a second battery cell group having a capacitance less than a capacitance of the first battery cell group; and

discharging the first battery cell group.

15. The method as claimed in claim 14, further comprising:

detecting a remaining battery amount of the first battery cell group;

when the remaining battery amount of the first battery cell group is less than a first threshold value, turning off the first switch and turning on the second switch; and

discharging the second battery cell group.

16. The method as claimed in claim 15, further comprising:

detecting a remaining battery amount of the second battery cell group; and

when the remaining battery amount of the second battery cell group is less than a second threshold value, turning off the second switch.

17. A method of controlling a battery pack, the method comprising:

turning on a first switch connected to a first battery cell group;

turning off a second switch connected to a second battery cell group having capacitance less than capacitance of the first battery cell group; and

charging the first battery cell group.

18. The method as claimed in claim 17, further comprising, when charging of the first battery cell group is completed:

turning off the first switch and turning on the second switch; and

charging the second battery cell group.

19. The method as claimed in claim 17, further comprising, when charging of the first battery cell group is performed, if discharging of the first battery cell group is needed, discharging the first battery cell group.

20. The method as claimed in claim 17, further comprising, when charging of the second battery cell group is performed, if discharging of the second battery cell group is needed:

turning off the second switch and turning on the first switch; and

discharging the first battery cell group.