Method and apparatus for charging batteries

• US 6,172,487 B1
• Filed: 04/15/1999
• Issued: 01/09/2001
• Est. Priority Date: 06/17/1998
• Status: Expired due to Term

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Brotto, Daniele C.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/292,166
• Time in Patent Office: 635 Days
• Field of Search: 320/150, 320/151, 320/154, 320/137, 320/134
• US Class Current: 320/150
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

The charging method includes providing a current to the battery pack, sensing battery temperature, determining temperature change rate, and disabling termination of the charging method based on a temperature-based scheme if the temperature change rate exceeds a first predetermined threshold within a first predetermined period of time. Termination of the charging method based on a temperature-based scheme may be re-enabled if the temperature change rate is less than a second predetermined threshold. Preferably the second predetermined threshold is equal to the first predetermined threshold. Alternatively, termination of the charging method based on a temperature-based scheme may be re-enabled after a second predetermined period of time has elapsed. Also disclosed herein is a battery charging method comprising providing a current to the battery pack, sensing battery temperature, determining temperature change rate, and suspending the current if the temperature change rate exceeds a first predetermined threshold within a first predetermined period of time. Current will be re-sent if the temperature change rate is less than a second predetermined threshold. Preferably the second predetermined threshold is equal to the first predetermined threshold. Alternatively, current will be re-sent after a second predetermined period of time has elapsed.

Claims

1. A method for charging a battery comprising:

providing a current to the battery;

sensing battery temperature;

determining temperature change rate;

disabling termination of the charging of the battery based on a temperature-based scheme if the temperature change rate exceeds a first predetermined threshold within a first predetermined period of time.

2. The method of claim 1, wherein the first predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

3. The method of claim 1, wherein the first predetermined threshold is about 1.2 Celsius degrees per minute.

4. The method of claim 1, wherein the first predetermined period of time is less than about 5 minutes.

5. The method of claim 1, wherein the first predetermined period of time is about 2 minutes.

6. The method of claim 1, further comprising re-enabling termination of the charging of the battery based on a temperature-based scheme if the temperature change rate is less than a second predetermined threshold.

7. The method of claim 6, wherein the second predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

8. The method of claim 6, wherein the second predetermined threshold is about 1.2 Celsius degrees per minute.

9. The method of claim 6, further comprising termination based on a voltage-based scheme prior to re-enablement of termination based on a temperature-based scheme.

10. The method of claim 1, further comprising re-enabling termination of the charging of the battery based on a temperature-based scheme after a second predetermined period of time has elapsed.

11. The method of claim 10, further comprising termination based on a voltage-based scheme prior to re-enablement of termination based on a temperature-based scheme.

12. The method of claim 1, wherein said temperature-based scheme is one of the group consisting of the absolute temperature scheme, temperature change rate scheme, and double derivative scheme.

13. A method for charging a battery comprising:

providing a current to the battery;

sensing battery temperature;

determining temperature change rate;

suspending providing of current based on a temperature-based scheme if the temperature change rate exceeds a first predetermined threshold within a first predetermined period of time.

14. The method of claim 13, wherein the first predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

15. The method of claim 13, wherein the first predetermined threshold is about 1.2 Celsius degrees per minute.

16. The method of claim 13, wherein the first predetermined period of time is less than about 5 minutes.

17. The method of claim 13, wherein the first predetermined period of time is about 2 minutes.

18. The method of claim 13, further comprising restarting charging if the temperature change rate is less than a second predetermined threshold.

19. The method of claim 18, wherein the second predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

20. The method of claim 18, wherein the second predetermined threshold is about 1.2 Celsius degrees per minute.

21. The method of claim 13, further restarting providing of current after a second predetermined period of time has elapsed.

22. A method for charging a battery comprising:

providing a current to the battery;

sensing battery temperature;

determining temperature change rate;

disabling a charging function if the temperature change rate exceeds a first predetermined threshold within a first predetermined period of time; and

re-enabling the charging function (1) if the temperature change rate is less than a second predetermined threshold or (2) after a second predetermined period of time has elapsed.

23. The method of claim 22, wherein the first predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

24. The method of claim 22, wherein the first predetermined threshold is about 1.2 Celsius degrees per minute.

25. The method of claim 22, wherein the first predetermined period of time is less than about 5 minutes.

26. The method of claim 22, wherein the first predetermined period of time is about 2 minutes.

27. The method of claim 22, wherein the second predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

28. The method of claim 22, wherein the second predetermined threshold is about 1.2 Celsius degrees per minute.

29. The method of claim 22, wherein the charging function is termination based on a temperature-based scheme.

30. The method of claim 29, wherein said temperature-based scheme is one of the group consisting of the absolute temperature scheme, temperature change rate scheme, and double derivative scheme.

31. The method of claim 22, wherein the charging function is providing current to the battery.

32. The method of claim 22, wherein the charging function is charging the battery.

33. A method for charging a battery comprising:

providing a current to the battery;

sensing battery temperature;

determining temperature change rate;

disabling termination of the charging of the battery based on a temperature-based scheme until (1) the temperature change rate is lower than a first predetermined threshold or (2) a first predetermined period of time has elapsed.

34. The method of claim 33, wherein the first predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

35. The method of claim 33, wherein the first predetermined threshold is about 1.2 Celsius degrees per minute.

36. The method of claim 33, wherein the first predetermined period of time is less than about 5 minutes.

37. The method of claim 33, wherein the first predetermined period of time is about 2 minutes.

38. The method of claim 33, further comprising termination of the charging of the battery based on a voltage-based scheme prior to re-enablement of termination based on a temperature-based scheme.

39. The method of claim 33, wherein said temperature-based scheme is one of the group consisting of the absolute temperature scheme, temperature change rate scheme, and double derivative scheme.

40. A method for charging a battery comprising:

providing a current to the battery;

sensing battery temperature;

determining temperature change rate;

disabling a charging function until (1) the temperature change rate is lower than a first predetermined threshold or (2) a first predetermined period of time has elapsed.

41. The method of claim 40, wherein the first predetermined threshold is between about 0.7 and 2.0 Celsius degrees per minute.

42. The method of claim 40, wherein the first predetermined threshold is about 1.2 Celsius degrees per minute.

43. The method of claim 40, wherein the first predetermined period of time is less than about 5 minutes.

44. The method of claim 40, wherein the first predetermined period of time is about 2 minutes.

45. The method of claim 40, wherein the charging function is termination based on a temperature-based scheme.

46. The method of claim 45, wherein said temperature-based scheme is one of the group consisting of the absolute temperature scheme, temperature change rate scheme, and double derivative scheme.