Battery system configured to survive failure of one or more batteries

• US 7,573,233 B1
• Filed: 08/08/2006
• Issued: 08/11/2009
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Quallion, LLC (EnerSys)
• Original Assignee: Quallion, LLC (EnerSys)
• Inventors: Tsukamoto, Hisashi, Tan, Taison, Chow, Lu
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US11/501,095
• Time in Patent Office: 1,099 Days
• Field of Search: 320/116, 320/117, 320/121, 320/134
• US Class Current: 320/116
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The battery system includes a battery pack having a plurality of power sources arranged in parallel groups that are connected in series. Each parallel group includes a plurality of power sources connected in parallel. Each power source includes a battery. The system also includes electronics configured to repeatedly charge the battery pack according to a charging protocol. The charging protocol is configured such that the voltage of any one battery in the battery pack does not exceed its maximum operational voltage after failure of a battery in the battery pack.

Claims

1. A battery system, comprising:

a battery pack having a plurality parallel groups connected in series, each parallel group including a plurality of power sources connected in parallel, each power source including a battery; and

electronics configured to repeatedly charge and discharge the battery pack according to a charging protocol configured such that the voltage of any one battery in the battery pack does not exceed its maximum operational voltage after failure of a battery in the battery pack, and wherein

the charging protocol includes charging the battery pack to a charged pack voltage that is less than a maximum operational voltage of the battery pack,

the charging protocol includes discharging the battery pack such that the battery pack discharge is stopped before the battery pack voltage falls to a discharged pack voltage,

the charged pack voltage being the same before and after the failure of the battery,

the discharged pack voltage being the same before and after the failure of the battery, and

the charged pack voltage and the discharged pack voltage are such that discharging the battery pack from the charged pack voltage to the discharged pack voltage before failure of the battery results in each battery providing a capacity that is less than or equal to C_m(M−

1)/(M+1), where M is the number of power sources in each parallel group and C_m is the maximum operational capacity of the battery.

2. The system of claim 1, wherein the electronics are configured to recharge the battery pack with the same charging protocol before failure of the battery and after failure of the battery.

3. The system of claim 1, wherein each power source consists of a battery.

4. The system of claim 1, wherein the charging protocol discharges the battery pack such that the voltage of any one battery in the battery pack does not fall below its minimum operational voltage after failure of a battery in the battery pack.

5. The system of claim 1, wherein the wherein the charging protocol includes discharging the battery pack such that the voltage of any one battery in the battery pack does not fall below its minimum operational voltage after failure of a battery in the battery pack.

6. The system of claim 1, further comprising:

a plurality of series groups, each series group connecting in series at least one of the power sources from each of the parallel groups.

17. The system of claim 1, wherein the charging protocol causes at least one of the batteries that has not failed to be charged to a higher voltage after failure of the battery than that battery was charged before the failure of the battery.

18. The system of claim 17, wherein the charging protocol is configured such that the higher voltage to which each of the at least one batteries is charged is less than a maximum operational voltage of each of the at least one batteries.

19. The system of claim 18, wherein each of the at least one batteries is included in the same parallel group with the battery that failed.

7. A battery system, comprising:

a battery pack having a plurality of parallel groups connected in series, each parallel group including a plurality of power sources connected in parallel, each power source including a battery; and

electronics configured to repeatedly charge and discharge the battery pack according to a charging protocol, wherein

the charging protocol includes repeatedly charging the battery pack to a charged pack voltage that is less than a maximum operational voltage of the battery pack,

the charged pack voltage being the same before and after the failure of the battery,

the charging protocol causing at least one of the batteries that has not failed to be charged to a higher voltage after failure of the battery than that battery was charged before the failure of the battery,

the charging protocol being configured such that the higher voltage to which each of the at least one batteries is charged is less than a maximum operational voltage of each one of the at least one batteries.

8. The system of claim 7, wherein the electronics are configured to discharge the battery pack with the same charging protocol before failure of the battery and after failure of the battery.

9. The system of claim 7, wherein each power source consists of a battery.

10. The system of claim 7, further comprising:

a plurality of series groups, each series group connecting in series at least one of the power sources from each of the parallel groups.

11. A method, comprising:

repeatedly charging a battery pack according to a charging protocol configured such that the voltage of any one battery in the battery pack does not exceed its maximum operational voltage after failure of a battery in the battery pack, the battery pack having a plurality of parallel groups connected in series, each parallel group including a plurality of power sources connected in parallel, each power source including a battery; and

the charging protocol includes charging the battery pack to a charged pack voltage that is less than a maximum operational voltage of the battery pack,

the charging protocol includes discharging the battery pack such that the battery pack discharge is stopped before the battery pack voltage falls to a discharged pack voltage,

the charged pack voltage being the same before and after the failure of the battery,

the discharged pack voltage being the same before and after the failure of the battery, and wherein

the charged pack voltage and the discharged pack voltage are such that discharging the battery pack from the charged pack voltage to the discharged pack voltage before failure of the battery results in each battery providing a capacity that is less than or equal to C_m(M−

1)/(M+1), where M is the number of power sources in each parallel group and C_m is the maximum operational capacity of the battery.

12. The method of claim 11, wherein the charging protocol is executed by electronics.

13. The method of claim 11, wherein the same charging protocol is employed before failure of the battery and after failure of the battery.

14. The method of claim 11, wherein each power source consists of a battery.

15. The method of claim 11, further comprising:

repeatedly discharging the battery pack according to the charging protocol and wherein the charging protocol is configured such that the voltage of any one battery in the battery pack does not fall below its minimum operational voltage after failure of a battery in the battery pack.

16. A method, comprising:

repeatedly discharging a battery pack according to a charging protocol, the battery pack having a plurality of parallel groups connected in series, each parallel group including a plurality of power sources connected in parallel, each power source including a battery, wherein

the charging protocol includes repeatedly charging the battery pack to a charged pack voltage that is less than a maximum operational voltage of the battery pack,

the charged pack voltage being the same before and after the failure of the battery,

the charging protocol causing at least one of the batteries that has not failed to be charged to a higher voltage after failure of the battery than that battery was charged before the failure of the battery,

the charging protocol being configured such that the higher voltage to which each of the at least one batteries is charged is less than a maximum operational voltage of each one of the at least one batteries.