Battery capacity predicting method, battery unit and apparatus using battery unit

• US 6,020,718 A
• Filed: 12/11/1996
• Issued: 02/01/2000
• Est. Priority Date: 07/01/1996
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Itoyama, Masami, Tanaka, Nobuo, Ozawa, Hidekiyo, Takeda, Yoshiro
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): SHIN, KYUNG E
• Application Number:
  US08/763,793
• Time in Patent Office: 1,147 Days
• Field of Search: 320/6, 320/15, 320/16, 320/17, 320/18, 320/32, 320/39, 320/48, 320/134, 320/135, 320/136, 320/116, 320/118, 320/120, 320/121, 320/112, 320/113, 320/122, 324/434
• US Class Current: 320/116
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H02H 7/18 for batteries; for accumulators
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery capacity predicting method predicts a remaining capacity of a battery unit including a plurality of battery cells connected in series in an apparatus which uses the battery unit. The battery capacity predicting method includes the steps of comparing output voltages of each of the battery cells, and predicting the remaining capacity of the battery unit based on at least one of a minimum voltage and a maximum voltage out of the compared output voltages of the battery cells.

Claims

1. A battery capacity predicting method predicting a remaining capacity of a battery unit including a plurality of battery cells having respective voltages and connected in series in an apparatus which uses the battery unit, said battery capacity predicting method comprising the steps of:

(a) comparing the respective voltages of the plurality of battery cells; and

(b) predicting the remaining capacity of the battery unit based on at least one of a minimum voltage and a maximum voltage of the compared, respective voltages of the plurality of battery cells.

2. The battery capacity predicting method as claimed in claim 1, wherein said step (b) predicts the remaining capacity of the battery unit based on the minimum voltage during discharge of the battery unit.

3. The battery capacity predicting method as claimed in claim 1, wherein said step (b) predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

4. The battery capacity predicting method as claimed in claim 2, wherein said step (b) predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

5. The battery capacity predicting method as claimed in claim 1, wherein said step (b) predicts a serviceable life of the battery unit based on a difference between the maximum voltage and the minimum voltage.

14. The battery capacity predicting method as claimed in claim 1, further comprising the step of:

(c) outputting an alarm based on the predicted remaining capacity of the battery unit.

15. The battery capacity predicting method as claimed in claim 14, wherein the alarm is output based on the battery cell having the minimum respective voltage.

6. A battery unit comprising:

a plurality of battery cells having respective voltages and connected in series;

an output circuit outputting at least one of a minimum voltage and a maximum voltage of the respective voltages of the battery cells;

a first cut-off circuit cutting off an output, to an outside of the battery unit, of a sum total voltage of the respective voltages of the plurality of battery cells when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to a first reference voltage; and

a second cut-off circuit cutting off the output, from the output circuit and to the outside of the battery unit, of the at least one of the minimum voltage and the maximum voltage cutting off operation of said first cut-off circuit.

7. The battery unit as claimed in claim 6, which further comprises:

a third cut-off circuit cutting off an output, to the outside of the battery unit, of a sum total voltage of the respective voltages of the battery cells when at least one of the respective voltages of the plurality of battery cells becomes greater than a second reference voltage which is different from the first reference voltage.

8. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells having respective voltages and connected in series, said apparatus comprising:

a coupler electrically coupling the battery unit to said apparatus; and

a predicting unit predicting the remaining capacity of the battery unit based on at least one of a minimum voltage and a maximum voltage of the respective voltages of the plurality of battery cells.

9. The apparatus as claimed in claim 8, wherein said predicting unit predicts the remaining capacity of the battery unit based on the minimum voltage during discharge of the battery unit.

10. The apparatus as claimed in claim 8, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

11. The apparatus as claimed in claim 9, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

12. The apparatus as claimed in claim 8, wherein said predicting unit predicts a serviceable life of the battery unit based on a difference between the maximum voltage and the minimum voltage.

13. The apparatus as claimed in claim 8, wherein said predicting unit, further, judges whether or not to charge the battery unit based on the predicted remaining capacity of the battery unit.

16. The apparatus as claimed in claim 8, further comprising:

an alarm unit generating an alarm in response to the predicted remaining capacity of the battery unit.

17. The apparatus as claimed in claim 16, wherein the alarm unit responds to the voltage of the minimum voltage level, of the respective voltages of the plurality of battery cells.

18. A method of predicting a remaining capacity of a battery unit which comprises a plurality of battery cells having respective voltages and connected in series in an apparatus which uses the battery unit, said method comprising the steps of:

(a) comparing the respective voltages of the plurality of battery cells; and

(b) predicting the remaining capacity of the battery unit based on a minimum voltage of the compared, respective voltages of the plurality of battery cells.

19. The method as claimed in claim 18, wherein said step (b) predicts the remaining capacity of the battery unit based on the minimum voltage during a discharge of the battery unit.

20. A method of predicting a remaining capacity of a battery unit including a plurality of battery cells having respective voltages and connected in series in an apparatus which uses the battery unit, said method comprising the steps of:

(a) comparing the respective voltages of the plurality of battery cells; and

(b) predicting the remaining capacity of the battery unit based on a maximum voltage of the compared, respective voltages of the plurality of battery cells.

21. The method as claimed in claim 20, wherein said step (b) predicts the remaining capacity of the battery unit based on the maximum voltage during a discharge of the battery unit.

22. A battery unit comprising a plurality of battery cells having respective voltages and connected in series, comprising:

an excessive-discharging and/or excessive-charging preventing circuit preventing excessive-discharging and/or excessive-charging of each of the plurality of battery cells; and

an output circuit outputting a minimum voltage and/or a maximum voltage of the respective voltages of the plurality of battery cells.

23. The battery unit as claimed in claim 22, wherein said excessive-discharging and/or excessive-charging preventing circuit includes a cut-off circuit cutting-off an output of a sum total voltage of the respective voltages of the plurality of battery cells to an outside of the battery unit when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to a reference voltage.

24. The battery unit as claimed in claim 22, wherein said excessive-discharging and/or excessive-charging preventing circuit includes a cut-off circuit cutting-off an output of a sum total voltage of the respective voltages of the plurality of battery cells to an outside of the battery unit when at least one of the respective voltages of the plurality of battery cells becomes greater than or equal to a reference voltage.

25. The battery unit as claimed in claim 23, further comprising:

a minimum voltage and/or maximum voltage cut-off circuit cutting-off the output, by the output circuit, of the minimum voltage and/or the maximum voltage to the outside of the battery unit responsive to an operation of said excessive-discharging and/or excessive-charging preventing circuit.

26. The battery unit as claimed in claim 22, further comprising:

a discharging switch discharging the plurality of battery units to an outside of the battery unit; and

said excessive-discharging and/or excessive-charging preventing circuit further including a switch opening circuit opening said discharging switch when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to reference voltage.

27. The battery unit as claimed in claim 22, further comprising:

a charging switch charging the plurality of battery units; and

said excessive-discharging and/or excessive-charging preventing circuit further including a switch opening circuit opening said charging switch when at least one of the voltages of the plurality of battery cells becomes greater than or equal to a reference voltage.

28. The battery unit as claimed in claim 26, further comprising:

a minimum voltage and/or maximum voltage cut-off circuit cutting-off the output of the minimum voltage and/or the maximum voltage to the outside of the battery unit responsive to an operation of said excessive-discharging and/or excessive-charging preventing circuit.

29. A battery unit comprising:

a plurality of battery cells connected in series and having respective output voltages;

an excessive-discharging preventing circuit preventing excessive-discharging of each of the plurality of battery cells; and

an output circuit outputting a minimum voltage of the respective voltages of the plurality of battery cells.

30. The battery unit as claimed in claim 29, wherein said excessive-discharging preventing circuit includes a cut-off circuit cutting-off an output of a sum total voltage of the respective voltages of the plurality of battery cells to an outside of the battery unit when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to a reference voltage.

31. The battery unit as claimed in claim 29, further comprising:

a minimum voltage and/or maximum voltage cut-off circuit cutting-off an output of the minimum voltage and/or the maximum voltage to the outside of the battery unit responsive to an operation of said excessive-discharging preventing circuit.

32. The battery unit as claimed in claim 29, further comprising:

a discharging switch discharging the plurality of battery cells to an outside of the battery unit; and

said excessive-discharging preventing circuit further including a switch opening circuit opening said discharging switch when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to a reference voltage.

33. The battery unit as claimed in claim 32, further comprising:

a minimum voltage and/or maximum voltage cut-off circuit cutting-off the output of the minimum voltage and/or the maximum voltage to the outside of the battery unit responsive to an operation of said excessive-discharging preventing circuit.

34. A battery unit comprising:

a plurality of battery cells connected in series and having respective voltages;

an excessive-charging preventing circuit preventing excessive-charging of each of the plurality of battery cells; and

an output circuit outputting a maximum voltage of the respective voltages of the plurality of battery cells.

35. The battery unit as claimed in claim 34, wherein said excessive-charging preventing circuit includes a cut-off circuit cutting-off an output of a sum total voltage of the respective voltages of the plurality of battery cells to an outside of the battery unit when at least one of the respective voltages of the plurality of battery cells becomes greater than or equal to a reference voltage.

36. The battery unit as claimed in claim 34, further comprising:

a charging switch charging the plurality of battery cells, said excessive-charging preventing circuit including a switch opening circuit opening said charging switch when at least one of the voltages of the plurality of battery cells becomes greater than or equal to a reference voltage.

37. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells having respective voltages and connected in series, said apparatus comprising:

a coupler electrically coupling the battery unit to said apparatus;

a terminal receiving a minimum voltage of the respective voltages of the plurality of battery cells of the battery unit; and

a detecting unit detecting over-discharging of the battery unit based on the minimum voltage.

38. The apparatus as claimed in claim 37, further comprising:

a predicting unit predicting a remaining capacity of the battery unit based on the minimum voltage during discharging of the battery unit.

41. The apparatus as claimed in claim 38, wherein said predicting unit predicts the remaining capacity of the battery unit based on a maximum voltage of the respective voltages of the plurality of battery cells of the battery unit during charging of the battery unit.

57. The battery unit as claimed in claim 37, further comprising:

a minimum voltage and/or maximum voltage cut-off circuit cutting-off an output of the minimum voltage and/or the maximum voltage to the outside of the battery unit when at least one of the respective voltages of the plurality of battery cells becomes less than or equal to a reference voltage.

39. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells having respective voltages and connected in series, said apparatus comprising:

a coupler electrically coupling the battery unit to said apparatus;

a terminal receiving a maximum voltage of the respective voltages of the battery cells of the battery unit; and

a detecting unit detecting over-charging of the battery unit based on the maximum voltage.

40. The apparatus as claimed in claim 39, further comprising:

a predicting unit predicting a remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

42. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells connected in series, comprising:

an output circuit outputting a minimum voltage and/or a maximum voltage of respective voltages of the plurality of battery cells; and

a predicting unit predicting the remaining capacity of the battery unit based on the minimum voltage and/or the maximum voltage.

43. The apparatus as claimed in claim 42, wherein said predicting unit predicts the remaining capacity of the battery unit based on the minimum voltage during discharging of the battery unit.

44. The apparatus as claimed in claim 42, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

45. An apparatus for predicting a remaining capacity of a battery unit which has a plurality of battery cells connected in series and having respective output voltages, comprising:

an output circuit outputting a minimum voltage of the respective voltages of the plurality of battery cells; and

a predicting unit predicting the remaining capacity of the battery unit based on the minimum voltage.

46. The apparatus as claimed in claim 45, wherein said predicting unit predicts the remaining capacity of the battery unit based on the minimum voltage during discharging of the battery unit.

47. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells connected in series and having respective output voltages, comprising:

an output circuit outputting a maximum voltage of the respective voltages of the plurality of battery cells; and

a predicting unit predicting the remaining capacity of the battery unit based on the maximum voltage.

48. The apparatus as claimed in claim 47, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

54. The apparatus as claimed in claim 47, wherein said judging unit judges the serviceable life of the battery unit based on a difference between the maximum battery cell voltage value and the minimum battery cell voltage value.

55. The apparatus as claimed in claim 48, wherein said judging unit judges the serviceable life of the battery unit based on a difference between the maximum battery cell voltage value and the minimum battery cell voltage value.

49. A method judging a serviceable life of a battery unit including a plurality of battery cells having respective voltages and connected in series in an apparatus which uses the battery unit, said method comprising the steps of:

(a) comparing the respective voltages of the plurality of battery cells; and

(b) judging the serviceable life of the battery unit based on a maximum battery cell voltage value and a minimum battery cell voltage value of the respective voltages of the plurality of battery cells.

50. The method as claimed in claim 49, wherein said step (b) judges the serviceable life of the battery unit based on a difference between the maximum battery cell voltage value and the minimum battery cell voltage value.

56. The apparatus as claimed in claim 49, wherein said judging unit judges the serviceable life of the battery unit based on a difference between the maximum battery cell voltage value and the minimum battery cell voltage value.

51. An apparatus judging a serviceable life of a battery unit which has a plurality of battery cells connected in series and having respective output voltages, said apparatus comprising:

a coupling unit electrically coupling the battery unit to said apparatus; and

a judging unit judging the serviceable life of the battery unit based on a maximum voltage and a minimum voltage of the respective voltages of the plurality of battery cells.

52. An apparatus judging a serviceable life of a battery unit which has a plurality of battery cells connected in series and having respective output voltages, said apparatus comprising:

a judging unit judging the serviceable life of the battery unit based on a maximum voltage and a minimum voltage of the respective voltages of the plurality of battery cells.

53. An apparatus judging a serviceable life of a battery unit which has a plurality of battery cells connected in series and having respective output voltages, comprising:

a comparing unit comparing voltages of each of the plurality of battery cells so as to derive a minimum battery cell voltage value and a maximum battery cell voltage value of the respective voltages of the plurality of battery cells; and

a judging unit judging the serviceable life of the battery unit based on the maximum cell voltage value and the minimum battery cell voltage value.

58. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells having respective voltages and connected in series, said apparatus comprising:

a predicting unit predicting the remaining capacity of the battery unit based on a minimum voltage of the respective voltages of the battery cells of the battery unit.

59. The apparatus as claimed in claim 58, further comprising:

a coupler electrically coupling the better unit to said apparatus.

60. The apparatus as claimed in claim 58, wherein said predicting unit predicts the remaining capacity of the battery unit based on the minimum voltage during discharge of the battery unit.

61. The apparatus as claimed in claim 58, further comprising:

a terminal receiving the minimum voltage of the respective voltages of the battery cells of the battery unit.

63. The apparatus as claimed in claim 58, further comprising:

a coupler electrically coupling the battery unit to said apparatus.

62. An apparatus predicting a remaining capacity of a battery unit which has a plurality of battery cells having respective voltages and connected in series, said apparatus comprising:

a predicting unit predicting the remaining capacity of the battery unit based on a maximum voltage of the respective voltages of the battery cells of the battery unit.

64. The apparatus as claimed in claim 62, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

65. The apparatus as claimed in claim 62, further comprising:

a terminal receiving the maximum voltage of the respective voltages of the plurality of battery cells of the battery unit.

66. An apparatus connectable to a battery unit of plural battery cells having respective voltages and connected in series, comprising:

a predicting unit predicting the remaining capacity of the battery unit based on a selected one of maximum and minimum voltages of the respective voltages of the plurality of battery cells.

67. The apparatus as claimed in claim 66, further comprising:

a coupler electrically coupling the battery unit to said apparatus.

68. The apparatus as claimed in claim 66, wherein said predicting unit predicts the remaining capacity of the battery unit based on the selected one of the maximum and minimum voltages during charging of the battery unit.

69. The apparatus as claimed in claim 66, further comprising:

a terminal receiving the selected one of the maximum and minimum voltages of the respective voltages of the plurality of battery cells of the battery unit.

70. An apparatus connectable to a battery unit of a plurality of battery cells having respective voltages and connected in series, comprising:

a predicting unit predicting a remaining capacity of the battery unit based on maximum voltage of the respective voltages of the plural battery cells.

71. The apparatus as claimed in claim 70, further comprising:

a coupler electrically coupling the apparatus to the battery unit.

72. The apparatus as claimed in claim 70, wherein said predicting unit predicts the remaining capacity of the battery unit based on the maximum voltage during charging of the battery unit.

73. An apparatus connectable to a battery unit of a plurality of battery cells having respective output voltages and connected in series, comprising:

a predicting unit predicting a remaining capacity of the battery unit based on a minimum voltage of the respective voltages of the plurality of battery cells.

74. The apparatus as claimed in claim 73, further comprising:

a coupler electrically coupling the apparatus to the battery unit.

75. The apparatus as claimed in claim 73, wherein said predicting unit predicts the remaining capacity of the battery unit based on the minimum voltage during discharging of the battery unit.