Battery system configured to survive failure of one or more batteries

• US 8,076,906 B2
• Filed: 07/28/2009
• Issued: 12/13/2011
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Quallion, LLC (EnerSys)
• Original Assignee: Quallion, LLC (EnerSys)
• Inventors: Chow, Lu, Tan, Taison, Tsukamoto, Hisashi
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US12/462,070
• Publication Number:
  US 20100117599A1
• Time in Patent Office: 868 Days
• Field of Search: 320/116, 320/117, 320/121, 320/134, 320/126, 320/135, 320/136, 320/137, 320/138, 320/130
• US Class Current: 320/135
• 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: 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 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 discharge the battery pack according to a charging protocol, wherein

the charging protocol includes repeatedly discharging the battery pack to a discharged pack voltage,

the discharged 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 discharged to a lower voltage after failure of the battery than that battery was discharged before the failure of the battery, and

the charging protocol being configured such that the lower voltage to which each of the at least one batteries is discharged is greater than a minimum operational voltage of each one of the at least one batteries.

2. The system of claim 1, 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.

3. The system of claim 2, wherein the charging protocol includes discharging the battery pack to a discharged pack voltage, the discharged pack voltage being the same before and after the failure of the battery.

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

5. 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.

12. The system of claim 1, wherein the discharged pack voltage is greater than a minimum operational voltage of the battery pack.

13. The system of claim 1, wherein the charging protocol includes charging the battery pack to a charged pack voltage, the charged pack voltage being the same before and after the failure of the battery.

14. The system of claim 13, wherein the capacity discharged from each battery when discharging from the charged pack voltage to the discharged pack voltage before failure of the battery 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 a battery.

15. The system of claim 1, wherein the charging protocol charges the battery pack such that the voltage of any one battery in the battery pack does not rise above its maximum operational voltage after failure of a battery in the battery pack.

16. The system of claim 1, 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.

17. 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.

6. 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 discharging the battery pack to a discharged pack voltage that is greater than a minimum operational voltage of the battery pack,

the discharged 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 discharged to a lower voltage after failure of the battery than that battery was discharged before the failure of the battery,

the charging protocol being configured such that the lower voltage to which each of the at least one batteries is discharged is greater than a minimum operational voltage of each one of the at least one batteries.

7. The method of claim 6, wherein the discharged pack voltage is greater than a minimum operational voltage of the battery pack.

8. The method of claim 6, wherein the charging protocol is executed by electronics.

9. The method of claim 6, wherein the same charging protocol is employed before failure of the battery and after failure of the battery.

10. The method of claim 6, wherein each power source consists of a battery.

11. The method of claim 6, wherein the charging protocol includes charging the battery pack to a charged pack voltage, the charged pack voltage being the same before and after the failure of the battery.