Method and apparatus for indicating battery charge status

• US 6,429,625 B1
• Filed: 05/18/2001
• Issued: 08/06/2002
• Est. Priority Date: 05/18/2001
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Palm, Inc. (TCL Technology Group Corp.)
• Inventors: Yamanaka, Keith, LeFevre, John S., Kwok, Alec
• Primary Examiner(s): Toatley, Gregory
• Application Number:
  US09/860,685
• Time in Patent Office: 445 Days
• Field of Search: 320/155, 320/158, 340/636, 340/635, 713/322
• US Class Current: 320/155
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition

Abstract

A method of indicating when a rechargeable battery of a handheld computer has been fully charged is disclosed. The method includes determining an elapsed charging time and activating a charge completion indicator when the elapsed charging time exceeds a predetermined time and requiring no dependence on actual battery voltage or current.

Claims

1. A method of indicating when a rechargeable battery of a handheld computer has been fully charged, comprising the steps of:

determining an elapsed charging time; and

activating a charge completion indicator when the elapsed charging time exceeds a predetermined time and requiring no dependence on actual battery voltage or current.

2. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, wherein the predetermined time is the estimated time required to fully charge the rechargeable battery from a completely discharged condition.

3. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, wherein the charge completion indicator is a visible indicator.

4. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 3, wherein the charge completion indicator is an icon.

5. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 4, wherein the icon is presented on a screen.

6. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, wherein the charge completion indicator is an audible alarm.

7. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, further comprising the steps of:

displaying a charging indicator; and

altering the charging indicator when the elapsed charging time exceeds the predetermined time.

8. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, further comprising the step of indicating the battery charging status by displaying an icon that changes as a linear function of the elapsed charging time.

9. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, further comprising:

calculating a discharge time; and

setting the predetermined time equal to zero if the discharge time is less than a first period of time.

10. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 9, wherein the first period of time is fifteen minutes.

11. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 1, further comprising:

calculating a discharge time; and

setting the predetermined time equal to a function of the discharge time.

12. The method of indicating when a rechargeable battery of a handheld computer has been fully charged of claim 11, wherein the predetermined time is set equal to three times the discharge time.

13. A handheld computer, comprising:

a display;

a rechargeable battery;

an operating system;

a battery charger; and

a timing routine, wherein the timing routine activates a charge completion indicator after the battery charger has been charging the rechargeable battery for a predetermined time the predetermined time being independent of a measured battery voltage or current.

14. The handheld computer of claim 13, wherein the predetermined time is the time required to fully charge the rechargeable battery from a completely discharged condition.

15. The handheld computer of claim 13, wherein the charge completion indicator is a visible indicator.

16. The handheld computer of claim 15, wherein the charge completion indicator is an icon.

17. The handheld computer of claim 16, wherein the icon is presented on a screen.

18. The handheld computer of claim 13, wherein the charge completion indicator is an audible alarm.

19. The handheld computer of claim 13, wherein the handheld computer indicates the battery charging status by displaying an icon that changes as a linear function of the elapsed charging time.

20. The handheld computer of claim 13, wherein the timing routine is a software routine residing in the operating system.

21. The handheld computer of claim 13, wherein the timing routine is part of the battery charger.

22. The handheld computer of claim 13, wherein the battery charger is a synchronization cradle.

23. The handheld computer of claim 13, wherein the battery charger is an AC power cord.

24. The handheld computer of claim 13, wherein the predetermined time is a function of a battery discharge time.

25. The handheld computer of claim 24, wherein the predetermined time is zero if the battery discharge time is less than fifteen minutes.

26. The handheld computer of claim 24, wherein the predetermined time is equal to three times the battery discharge time.

27. A method of indicating when a rechargeable battery has been fully charged, comprising the steps of:

determining an elapsed charging time; and

activating a charge completion indicator when the elapsed charging time exceeds a predetermined time the predetermined time being independent of a measured battery voltage or current.

28. The method of indicating when a rechargeable battery has been fully charged of claim 27, wherein the predetermined time is the estimated time required to fully charge the rechargeable battery from a completely discharged condition.

29. The method of indicating when a rechargeable battery has been fully charged of claim 27, wherein the charge completion indicator is a visible indicator.

30. The method of indicating when a rechargeable battery has been fully charged of claim 27, wherein the charge completion indicator is an audible alarm.

31. A method of charging a rechargeable battery of a handheld computer, comprising the steps of:

providing a battery charger;

providing a timer;

electrically linking the rechargeable battery and the battery charger, thereby commencing battery charging;

determining an elapsed charging time; and

indicating completion of battery charging when the elapsed charging time exceeds a predetermined time the predetermined time being independent of a measured battery voltage or current.

32. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the predetermined time is the estimated time required to fully charge the rechargeable battery from a completely discharged condition.

33. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein a charge completion indicator is activated to indicate completion of battery charging.

34. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the charge completion indicator is a visible indicator.

35. The method of charging a rechargeable battery of a handheld computer of claim 34, wherein the charge completion indicator is an icon.

36. The method of charging a rechargeable battery of a handheld computer of claim 35, wherein the icon is presented on a screen.

37. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the charge completion indicator is an audible alarm.

38. The method of charging a rechargeable battery of a handheld computer of claim 31, further comprising the steps of:

displaying a charging indicator; and

removing the charging indicator when the elapsed charging time exceeds the predetermined time.

39. The method of charging a rechargeable battery of a handheld computer of claim 31, further comprising the step of indicating the status of battery charging with an indicator that changes as a linear function of the elapsed charging time.

40. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the timer is a software routine residing in an operating system of the handheld computer.

41. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the timer is part of the battery charger.

42. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the battery charger is a synchronization cradle.

43. The method of charging a rechargeable battery of a handheld computer of claim 31, wherein the battery charger is an AC power cord.

44. A synchronization cradle, comprising:

a current source coupled to a battery charging circuit; and

a battery charge status indicator;

wherein the battery charge status indicator indicates that a rechargeable battery is fully charged after a predetermined charging time has elapsed the predetermined charging time being independent of a measured battery voltage or current.

45. The synchronization cradle of claim 44, wherein the predetermined elapsed charging time is the estimated time required to fully charge the rechargeable battery from a completely discharged condition.

46. The synchronization cradle of claim 44, wherein the synchronization cradle indicates the status of battery charging by displaying an indicator that changes as a linear function of the elapsed charging time.