Rechargeable battery maintenance and testing system

• US 6,137,261 A
• Filed: 01/26/1998
• Issued: 10/24/2000
• Est. Priority Date: 01/26/1998
• Status: Expired due to Term

• Current Assignee: Physio-Control Incorporated (Stryker Corporation)
• Original Assignee: Physio-Control Corporation
• Inventors: Johnson, Stephen B., Nordness, Rockland W., Firman, Stephen L., Gustavson, Douglas M., Kurle, Wayne D.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/013,409
• Time in Patent Office: 1,002 Days
• Field of Search: 320/137, 320/128, 320/132, 320/134, 320/135, 320/136, 320/131, 320/130, 320/150
• US Class Current: 320/132
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation

Abstract

A battery maintenance and testing system (22) that includes a battery support system (2) that tests, conditions, and charges rechargeable battery packs. The battery support system (22) accommodates a dumb battery (32) that do not have any internal logic by running a default maintenance routine, as well as a smart battery (24, 24'"'"') that has internal logic that monitors its condition, keeps track of the time and number of charge discharge cycles the battery has experienced since it was last conditioned, logs any errors that would necessitate the battery being discarded, and stores information relevant to its maintenance and testing. The battery maintenance and testing system (22) is able to communicate with a smart battery (24, 24'"'"') to automatically to retrieve this information and use it to condition, test, and charge the battery to optimal condition or to indicate to the user that the battery is defective and needs to be discarded. A user display and interface (43) is also provided on the battery support system that allows the user to manually charge, condition, or test a rechargeable battery pack.

Claims

1. A method for maintaining and testing a rechargeable battery, the method comprising:

(a) determining if the rechargeable battery is a smart battery or a dumb battery by detecting the presence of at least one communication signal and at least one temperature dependent signal from the rechargeable battery; and

(b) performing at least one battery maintenance and testing routine on the rechargeable battery based upon whether the rechargeable battery is a smart battery or a dumb battery.

2. The method of claim 1, wherein performing the at least one battery maintenance and testing routine comprises charging the rechargeable battery in accordance with a charging algorithm based upon a chemistry of the rechargeable battery.

3. The method of claim 2, wherein if the rechargeable battery is a smart battery, the chemistry of the rechargeable battery is obtained from the rechargeable battery, and wherein if the rechargeable battery is a dumb battery the chemistry of the rechargeable battery is set to a default chemistry.

4. The method of claim 1, further indicating that the rechargeable battery should be discarded, if the at least one battery maintenance and testing routine fails.

5. The method of claim 4, wherein indicating that the rechargeable battery should be discarded comprises:

(a) issuing a battery fault indicator; and

(b) sending a battery fault message to the rechargeable battery, if the rechargeable battery is a smart battery.

6. The method of claim 1, further comprising maintaining the rechargeable battery in operating condition if the at least one battery maintenance and testing routine is successful.

7. The method of claim 6, wherein maintaining the rechargeable battery in operating condition comprises:

(a) applying a maintenance charge to the rechargeable battery; and

(b) after a maximum charge maintenance period, conditioning the rechargeable battery.

8. The method of claim 7, wherein the maintenance charge is applied to the rechargeable battery based upon a chemistry of the rechargeable battery.

9. The method of claim 8, wherein if the rechargeable battery is a smart battery, the chemistry of the rechargeable battery is obtained from the rechargeable battery, and wherein if the rechargeable battery is a dumb battery the chemistry of the rechargeable battery is set to a default chemistry.

10. A method for maintaining and testing a rechargeable battery, the method comprising:

(a) determining if the rechargeable battery is a smart battery or a dumb battery; and

(b) performing at least one battery maintenance and testing routine on the rechargeable battery based upon whether the rechargeable battery is a smart battery or a dumb battery, wherein the at least one battery maintenance and testing routine comprises conditioning the rechargeable battery by;

(i) charging the rechargeable battery;

(ii) performing a pulse discharge test on the rechargeable battery to determine if the rechargeable battery is capable of delivering a sufficient high current pulse; and

(iii) if the rechargeable battery is capable of delivering a sufficient high current pulse, discharging the rechargeable battery and recharging the rechargeable battery.

11. The method of claim 10, wherein the rechargeable battery is conditioned based upon a chemistry of the rechargeable battery.

12. The method of claim 11, wherein if the rechargeable battery is a smart battery, the chemistry of the rechargeable battery is obtained from the rechargeable battery, and wherein if the rechargeable battery is a dumb battery the chemistry of the rechargeable battery is set to a default chemistry.

13. The method of claim 10, wherein the pulse discharge test determines if the rechargeable battery is capable of delivering a sufficient high current pulse by:

(a) drawing a high current, short duration pulse from the rechargeable battery;

(b) measuring the voltage of the rechargeable battery during the high current, short duration pulse; and

(b) determining if the measured voltage remains above a predetermined minimum voltage threshold.

14. The method of claim 13, wherein the high current, short duration pulse is drawn from the rechargeable battery at a plurality of pulse discharge intervals.

15. The method of claim 13, wherein the measured voltage is determined to remain above a predetermined minimum voltage threshold if the measured voltage does not fall below the predetermined minimum voltage threshold during a maximum pulse discharge interval.

16. The method of claim 15, wherein the maximum pulse discharge interval is a pulse discharge interval during which a charge capacity of the rechargeable battery is expected to be between an upper percentage of a nominal capacity and a lower percentage of a nominal capacity.

17. The method of claim 15, wherein a pulse discharge interval is based upon an amount of current that would discharge a full capacity battery during a particular time interval.

18. A method for maintaining and testing a rechargeable battery, the method comprising:

(a) determining if the rechargeable battery is a smart battery or a dumb battery;

(b) performing at least one battery maintenance and testing routine on the rechargeable battery based upon whether the rechargeable battery is a smart battery or a dumb battery, wherein the at least one battery maintenance and testing routine determines if the rechargeable battery is excessively self-discharging by;

(i) discharging the rechargeable battery;

(ii) during discharge of the rechargeable battery, measuring an actual delivered charge capacity of the rechargeable battery; and

(iii) determining if the actual delivered charge capacity is less than a minimum target capacity.

19. The method of claim 18, wherein determining if the rechargeable battery is excessively self-discharging further comprises:

(a) charging the rechargeable battery to fill capacity; and

(b) storing the rechargeable battery open-circuited for a predetermined period of time.

20. The method of claim 19, wherein the rechargeable battery is discharged and charged based upon a chemistry of the rechargeable battery.

21. The method of claim 20, wherein if the rechargeable battery is a smart battery, the chemistry of the rechargeable battery is obtained from the rechargeable battery, and wherein if the rechargeable battery is a dumb battery the chemistry of the rechargeable battery is set to a default chemistry.

22. The method of claim 18, wherein determining if the rechargeable battery is excessively self-discharging further comprises obtaining an excessive self-discharge report from the rechargeable battery, if the rechargeable battery is a smart battery.

23. An apparatus for maintaining and testing a rechargeable battery, the apparatus comprising:

(a) at least one battery well for receiving a rechargeable battery for maintenance and testing;

(b) a charging and discharging unit for discharging and charging the rechargeable battery received by the at least one battery well;

(c) a first non-volatile memory for storing program instructions for maintaining and testing the rechargeable battery; and

(d) a processing unit coupled to the at least one battery well via a communication bus, the charging and discharging unit, and the first non-volatile memory, wherein the processing unit executes the program instructions which maintain and test the rechargeable battery by;

(i) determining if the rechargeable battery is a smart battery or a dumb battery; and

(ii) implementing at least one of a plurality of maintenance and testing modes which cause the charging and discharging unit to charge and recharge the rechargeable battery in a manner so as to maintain and test the condition of the rechargeable battery while in the at least one battery well, wherein the maintenance and testing modes are implemented based upon whether the rechargeable battery is a smart battery or a dumb battery.

24. The apparatus of claim 23, wherein the processing unit determines that the rechargeable battery is a smart battery if the processing unit detects that the presence of at least one communication signal on the communication bus and at least one temperature-dependent signal on the rechargeable battery.

25. The apparatus of claim 23, wherein the at least one maintenance and testing mode implemented by the processing unit is a charging mode which causes the discharging and charging unit to charge the rechargeable battery in accordance with a charging algorithm based upon a chemistry of the rechargeable battery.

26. The apparatus of claim 25, wherein if the rechargeable battery is a smart battery, the processing unit obtains the chemistry of the rechargeable battery from the rechargeable battery via the communication bus;

and wherein if the rechargeable battery is a dumb battery the processing unit sets the chemistry of the rechargeable battery to a default chemistry.

27. The apparatus of claim 23, wherein the processing unit implements a discard mode which indicates that the rechargeable battery should be discarded, if any of the maintenance and testing modes implemented by the processing unit fails.

28. The apparatus of claim 27, wherein the discard mode indicates that the rechargeable battery should be discarded by:

(a) causing the processing unit to issue battery fault indicator; and

(b) causing the processing unit to send a battery fault message to the rechargeable battery via the communication bus, if the rechargeable battery is a smart battery.

29. The apparatus of claim 23, wherein the processing unit implements a ready mode which maintains the rechargeable battery in operating condition if the at least one other mode is successful.

30. The apparatus of claim 29, wherein the ready mode maintains the rechargeable battery in operating condition by:

(a) causing the charging and discharging unit to apply a maintenance charge to the rechargeable battery; and

(b) after a maximum charge maintenance period, causing the processing unit to implement a conditioning mode which conditions the rechargeable battery.

31. The apparatus of claim 30, wherein the charging and discharging unit applies the maintenance charge to the rechargeable battery based upon a chemistry of the rechargeable battery.

32. The apparatus of claim 31, wherein if the rechargeable battery is a smart battery, the processing unit obtains the chemistry of the rechargeable battery from the rechargeable battery, and wherein if the rechargeable battery is a dumb battery the processing unit sets the chemistry of the rechargeable battery to a default chemistry.

33. The apparatus of claim 23, wherein the processing unit implements at least one of the maintenance and testing modes upon expiration of a predetermined time interval.

34. The apparatus of claim 23, wherein the processing unit implements at least one of the maintenance and testing modes in response to user input from a user display and interface coupled to the processing unit.

35. The apparatus of claim 23, wherein the processing unit implements at least one of the maintenance and testing modes if the rechargeable battery is a smart battery and a maintenance flag is set in the rechargeable battery.

36. An apparatus for maintaining and testing a rechargeable battery, the apparatus comprising:

(a) at least one battery well for receiving a rechargeable battery for maintenance and testing;

(b) a charging and discharging unit for discharging and charging the rechargeable battery received by the at least one battery well;

(c) a first non-volatile memory for storing program instructions for maintaining and testing the rechargeable battery; and

(d) a processing unit coupled via a communication bus to the at least one battery well, the charging and discharging unit, and the first non-volatile memory, wherein the processing unit executes the program instructions which maintain and test the rechargeable battery by;

(i) determining if the rechargeable battery is a smart battery or a dumb battery; and

(ii) implementing at least one of a plurality of maintenance and testing modes which cause the charging and discharging unit to charge and recharge the rechargeable battery in a manner so as to maintain and test the condition of the rechargeable battery while in the at least one battery well, wherein the at least one maintenance and testing mode is a conditioning mode which conditions the rechargeable battery by;

(A) causing the charging and discharging unit to charge the rechargeable battery;

(B) performing a pulse discharge test on the rechargeable battery to determine if the rechargeable battery is capable of delivering a sufficient high current pulse; and

(C) if the rechargeable battery is capable of delivering a sufficient high current pulse, causing the charging and discharging unit to discharge the rechargeable battery and recharge the rechargeable battery.

37. The apparatus of claim 36, wherein the conditioning mode conditions the rechargeable battery based upon a chemistry of the rechargeable battery.

38. The apparatus of claim 37, wherein if the rechargeable battery is a smart battery, the processing unit obtains the chemistry of the rechargeable battery from the rechargeable battery via the communication bus, and wherein if the rechargeable battery is a dumb battery the processing unit sets the chemistry of the rechargeable battery to a default chemistry.

39. The apparatus of claim 36, wherein the pulse discharge test determines if the rechargeable battery is capable of delivering a sufficient high current pulse by:

(a) causing the charging and discharging unit to draw a high current, short duration pulse from the rechargeable battery;

(b) measuring the voltage of the rechargeable battery during the high current, short duration pulse; and

(b) determining if the measured voltage remains above a predetermined minimum voltage threshold.

40. The apparatus of claim 39, wherein the charging and discharging unit draws the high current, short duration pulse from the rechargeable battery at a plurality of pulse discharge intervals.

41. The apparatus of claim 39, wherein the measured voltage is determined to remain above a predetermined minimum voltage threshold if the measured voltage does not fall below the predetermined minimum voltage threshold during a maximum pulse discharge interval.

42. The apparatus of claim 41, wherein the maximum pulse discharge interval is a pulse discharge interval during which a charge capacity of the rechargeable battery is expected to be between an upper percentage of a nominal capacity and a lower percentage of a nominal capacity.

43. The apparatus of claim 42, wherein a pulse discharge interval is based upon an amount of current that would discharge a full capacity battery during a particular time interval.

44. The apparatus of claim 36, wherein after the charging and discharging unit discharges and recharges the rechargeable battery during the condition mode, the processing unit implements a ready mode which maintains the rechargeable battery in operating condition.

45. The apparatus of claim 36, wherein if the rechargeable battery is not capable of delivering a sufficient high current pulse, the processing unit implements a discard mode which indicates that the rechargeable battery should be discarded.

46. An apparatus for maintaining and testing a rechargeable battery, the apparatus comprising:

(a) at least one battery well for receiving a rechargeable battery for maintenance and testing;

(b) a charging and discharging unit for discharging and charging the rechargeable battery received by the at least one battery well;

(c) a first non-volatile memory for storing program instructions for maintaining and testing the rechargeable battery; and

(d) a processing unit coupled via a communication bus to the at least one battery well, the charging and discharging unit, and the first non-volatile memory, wherein the processing unit executes the program instructions which maintain and test the rechargeable battery by;

(i) determining if the rechargeable battery is a smart battery or a dumb battery; and

(ii) implementing at least one of a plurality of maintenance and testing modes which cause the charging and discharging unit to charge and recharge the rechargeable battery in a manner so as to maintain and test the condition of the rechargeable battery while in the at least one battery well, wherein the at least one maintenance and testing mode is a conditioning mode which conditions the rechargeable battery by;

if the rechargeable battery is a dumb battery,

(A) causing the charging and discharging unit to discharge the rechargeable battery;

(B) during discharge of the rechargeable battery, measuring an actual delivered charge capacity of the rechargeable battery; and

(C) determining if the actual delivered charge capacity is less than a minimum target capacity.

47. The apparatus of claim 46, wherein the shelf-life mode further determines if the rechargeable battery is excessively self-discharging by:

if the rechargeable battery is a dumb battery,

(a) causing the charging and discharging unit to charge the rechargeable battery to full capacity; and

(b) requiring that the rechargeable battery open-circuited be stored in the at least one battery well for a predetermined period of time.

48. The apparatus of claim 47, wherein the shelf-life mode causes the charging and discharging unit to discharge and charge the rechargeable battery based upon a chemistry of the rechargeable battery.

49. The apparatus of claim 48, wherein if the rechargeable battery is a smart battery, the processing unit obtains the chemistry of the rechargeable battery from the rechargeable battery via the communication bus, and wherein if the rechargeable battery is a dumb battery the processing unit sets the chemistry of the rechargeable battery to a default chemistry.

50. The apparatus of claim 46, wherein if the actual delivered charge capacity is less than the minimum target capacity, the processing unit implements a discard mode which indicates that the rechargeable battery should be discarded.

51. The apparatus of claim 46, wherein the shelf-life mode determines if the rechargeable battery is excessively self-discharging by causing the processing unit to obtain an excessive self-discharge report from the rechargeable battery via the communication bus if the rechargeable battery is a smart battery.

52. The apparatus of claim 51, wherein if the processing unit obtains an excessive self-discharge report from the rechargeable battery, the processing unit implements a discard mode which indicates that the rechargeable battery should be discarded.

53. The apparatus of claim 51, wherein if the rechargeable battery is not excessively self-discharging, the processing unit implements a ready mode which maintains the rechargeable battery in operating condition.

54. A rechargeable battery maintenance and testing system for conditioning, testing and charging a rechargeable battery, the system comprising:

(a) a stand-by mode for determining if the rechargeable battery is a smart battery or a dumb battery;

(b) a conditioning mode for conditioning the rechargeable battery;

(c) a charging mode which charges the rechargeable battery; and

(d) a shelf-life mode which determines if the rechargeable battery is excessively self-discharging, wherein implementation of the conditioning mode, the charging mode and the shelf-life mode depends upon whether the rechargeable battery is a dumb battery or a smart battery.

55. The system of claim 54, wherein the stand-by mode determines if the rechargeable battery is a smart battery by determining if the rechargeable battery has communication ability.

56. The system of claim 55, wherein if the rechargeable battery has communication ability, the stand-by mode obtains a battery type, a state of charge, a conditioning flag and a fault flag from the rechargeable battery, and wherein if the rechargeable battery does not have communication ability, the stand-by mode sets the battery type to a default type.

57. The system of claim 56, wherein the conditioning conditions the rechargeable battery by:

(a) charging the rechargeable battery according to the battery type;

(b) performing a pulse discharge test on the rechargeable battery to determine if the rechargeable battery needs to be discarded; and

(c) if the rechargeable battery does not need to be discarded, discharging the rechargeable battery and recharging the rechargeable battery according to the battery type.

58. The system of claim 57, wherein the pulse discharge test determines if the rechargeable battery needs to be discarded by:

(a) performing at least one pulse discharge of the rechargeable battery;

(b) measuring the voltage of the rechargeable battery during the pulse discharge; and

(c) determining if the measured voltage remains above a predefined end discharge voltage for a predetermined maximum pulse discharge interval.

59. The system of claim 58, wherein a plurality of pulse discharges of the rechargeable battery are performed.

60. The system of claim 59, wherein the maximum pulse discharge interval is based upon an amount of current that would discharge a full capacity battery during a particular time interval.

61. The system of claim 57, wherein after the conditioning mode discharges and recharges the rechargeable battery, the conditioning mode transitions to a ready mode which maintains the rechargeable battery in operating condition.

62. The system of claim 57, wherein if the conditioning modes determines that the rechargeable battery needs to be discarded, the conditioning mode transitions to a discard mode which indicates that the rechargeable battery should be discarded.

63. The system of claim 56, wherein the charging mode charges the rechargeable battery in accordance with a charging algorithm based upon the battery type of the rechargeable battery.

64. The system of claim 56, wherein the shelf-life mode determines if the rechargeable battery is excessively self-discharging by:

if the rechargeable battery is a dumb battery,

(a) discharging the rechargeable battery according to the battery type of the rechargeable battery;

(b) during discharge of the rechargeable battery, measuring an actual delivered charge capacity of the rechargeable battery; and

(c) determining if the actual delivered charge capacity is less than a minimum target capacity.

65. The system of claim 64, wherein if the actual delivered charge capacity is less than the minimum target capacity, the shelf-life mode transitions to a discard mode which indicates that the rechargeable battery should be discarded.

66. The system of claim 64, wherein the shelf-life mode determines if the rechargeable battery is excessively self-discharging from the state of charge obtained from the rechargeable battery, if the rechargeable battery is a smart battery.

67. The system of claim 66, wherein if the shelf-life mode obtains determines if the rechargeable battery is excessively self-discharging from the state of charge, the shelf-life mode transitions to a discard mode which indicates that the rechargeable battery should be discarded.

68. The system of claim 67, wherein if the rechargeable battery is not excessively self-discharging, the shelf-life mode transitions to a ready mode which maintains the rechargeable battery in operating condition.

69. The system of claim 54, further comprising a discard mode which indicates that the rechargeable battery should be discarded, wherein the discard mode is entered if any one of the stand-by mode, conditioning mode, charging mode and shelf-life mode fails.

70. The system of claim 69, wherein the discard mode indicates that the rechargeable battery should be discarded by:

(a) issuing a battery fault indicator; and

(b) sending a battery fault message to the rechargeable battery, if the rechargeable battery is a smart battery.

71. The system of claim 54, further comprising a ready mode which maintains the rechargeable battery in operating condition, wherein the ready mode is entered if any of the conditioning mode, charging mode and shelf-life mode are successful.

72. The system of claim 71, wherein the ready mode maintains the rechargeable battery in operating condition by:

(a) applying a maintenance charge to the rechargeable battery in accordance with the battery type of the rechargeable battery; and

(b) after a maximum charge maintenance period, entering the conditioning mode which conditions the rechargeable battery.

73. The system of claim 54, wherein the system transitions between the stand-by mode, the conditioning mode, the charging mode, and the shelf-life mode upon expiration of a predetermined time interval.

74. The system of claim 54, wherein the system transitions between the stand-by mode, the conditioning mode, the charging mode, and the shelf-life mode in response to user input.

75. The system of claim 54, wherein the system transitions between the stand-by mode, the conditioning mode, the charging mode, and the shelf-life mode in response to a maintenance flag on the rechargeable battery, if the rechargeable battery is a smart battery.

76. A method of conditioning a rechargeable battery comprising:

(a) charging the rechargeable battery;

(b) performing a pulse discharge test on the rechargeable battery to determine if the rechargeable battery is capable of delivering a sufficient high current pulse; and

(c) if the rechargeable battery is capable of delivering a sufficient high current pulse, discharging the rechargeable battery and recharging the rechargeable battery.

77. The method of claim 76, wherein the pulse discharge test determines if the rechargeable battery is capable of delivering a sufficient high current pulse by:

(a) drawing a high current, short duration pulse from the rechargeable battery;

(b) measuring the voltage of the rechargeable battery during the high current, short duration pulse; and

(c) determining if the measured voltage remains above a predetermined minimum voltage threshold.

78. The method of claim 76, wherein the high current, short duration pulse is drawn from the rechargeable battery at a plurality of pulse discharge intervals.

79. The method of claim 77, wherein the measured voltage is determined to remain above a predetermined minimum voltage threshold if the measured voltage does not fall below the predetermined minimum voltage threshold during a maximum pulse discharge interval.

80. The method of claim 79, wherein the maximum pulse discharge interval is a pulse discharge interval during which a charge capacity of the rechargeable battery is expected to be between an upper percentage of a nominal capacity and lower percentage of a nominal capacity.

81. The method of claim 79, wherein a pulse discharge interval is based upon an amount of current that would discharge a full capacity battery during a particular time interval.