Battery charge control circuit, battery charging device, and battery charge control method

• US 6,452,364 B1
• Filed: 03/22/2000
• Issued: 09/17/2002
• Est. Priority Date: 04/09/1999
• Status: Expired due to Term

• Current Assignee: Fujitsu Client Computing Limited (Lenovo Group Ltd.)
• Original Assignee: Fujitsu Limited
• Inventors: Ozawa, Hidekiyo, Saeki, Mitsuo, Kitagawa, Seiya, Matsuyama, Toshiyuki
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): Luk, Lawrence
• Application Number:
  US09/532,790
• Time in Patent Office: 909 Days
• Field of Search: 320/137, 320/138, 320/125, 320/156, 320/162
• US Class Current: 320/137
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A battery charge control circuit, a battery charging device, and a battery charge control method for controlling the charging of a battery are provided. A power source supplies a current to a load, and a battery also supplies a current to the load. If the current supply capacity of the power source is restricted when the power source charges the battery, the charging of the battery is not stopped. Thus, a wrong operation can be avoided, and more reliable battery charging can be performed.

Claims

1. A battery charge control circuit which controls a charging current for charging a battery part, comprising:

a restriction notifying unit which detects a restriction on the supply capacity of a power source, and outputs a notification that the supply capacity of the power source is restricted.

2. The battery charge control circuit as claimed in claim 1, further comprising:

a first control circuit which controls the charging current for the battery part, so that the battery part can be charged in accordance with predetermined charging conditions; and

a second control circuit which controls the charging current so that the power supplied from the power source does not exceed the supply capacity,

wherein the restriction notifying unit notifies that the charging current is controlled by the second control circuit.

3. The battery charge control circuit as claimed in claim 1, wherein the power source charges the battery part and supplies power to a load.

4. The battery charge control circuit as claimed in claim 1, wherein the battery part includes a plurality of batteries connected in parallel.

5. The battery charge control circuit as claimed in claim 1, wherein the restriction notifying unit detects the charging current for charging the battery part and, in accordance with the charging current, outputs a notification that the supply capacity of the power source is restricted.

6. The battery charge control circuit as claimed in claim 5, wherein the restriction notification unit detects the charging current for charging the battery part and, in accordance with the difference between the charging current for the battery part and a current demanded by the battery part, outputs the notification that the supply capacity of the power source is restricted.

7. The battery charge control circuit as claimed in claim 1, wherein the restricted notifying unit detects a charging voltage of the battery part and, in accordance with the charging voltage, outputs a notification that the supply capacity of the power source is restricted.

8. The battery charge control circuit as claimed in claim 7, wherein the restriction notifying unit detects the charging voltage of the battery part and, in accordance with a difference between the charging voltage of the battery part and a voltage demanded by the battery part, outputs the notification that the supply capacity of the power source is restricted.

9. The battery charge control circuit as claimed in claim 1, wherein the restriction notifying unit detects an output current of the power source and, in accordance with the detected output current of the power source, outputs a notification that the supply capacity of the power source is restricted.

10. The battery charge control circuit as claimed in claim 9, wherein the restriction notifying unit detects the output current of the power source and, in accordance with a difference between the output current of the power source and the maximum current that can be supplied from the power source, outputs the notification that the supply capacity of the power source is restricted.

11. The battery charge control circuit as claimed in claim 1, wherein the restriction notifying unit detects an output voltage of the power source and, in accordance with the output voltage of the power source, outputs a notification that the supply capacity of the power source is restricted.

12. The battery charge control circuit as claimed in claim 11, wherein the restriction notifying unit detects the output voltage of the power source and, in accordance with the difference between the output voltage of the power source and a predetermined reference voltage, outputs the notification that the supply capacity of the power source is restricted.

13. The battery charge control circuit as claimed in claim 1, wherein the notification outputted from the restriction notifying unit is that the current supply capacity of the power source is restricted.

14. The battery charge control circuit as claimed in claim 1, wherein the notification outputted from the restriction notifying unit is that the power supply capacity of the power source is restricted.

15. A battery charge control circuit comprising:

a first control circuit which controls a current supplied from a power source so that a battery part is charged at a constant current and/or a constant voltage;

a second control circuit which controls a charging current for the battery part in accordance with an output of the power source; and

a determination unit which determines whether the charging current for the battery part is controlled by the second control circuit.

16. The battery charge control circuit as claimed in claim 15, wherein the determination unit determines whether the charging current for the battery part is controlled by the first control circuit or the second control circuit.

17. The battery charge control circuit as claimed in claim 15, further comprising a determination result output unit which outputs a determination result of the determination unit.

18. A battery charge control circuit comprising:

a first control circuit which controls a current supplied from a power source so that a plurality of batteries are charged at a constant current and/or a constant voltage;

a second control circuit which controls charging currents for the plurality of batteries in accordance with an output of the power source; and

a determination unit which determines whether the charging currents for the plurality of batteries are controlled by the second control circuit.

19. The battery charge control circuit as claimed in claim 18, wherein the first control circuit controls the charging currents and/or voltages so that the charging current for the plurality of batteries are regulated when voltages of the plurality of batteries are lower than a predetermined reference voltage, and the charging voltage for the plurality of batteries are regulated when the voltages of the plurality of batteries are higher than the predetermined reference voltage.

20. A battery charge control circuit which controls a charging current for charging a battery part, said circuit comprising:

a first control circuit which controls the charging current for the battery part so that the battery can be charged in accordance with predetermined charging conditions;

a second control circuit which controls the charging current for the battery part so that power supplied from a power source does not exceed a predetermined capacity; and

a determination unit which determines whether the charging current for the battery part is controlled by the second control circuit.

21. The battery charge control circuit as claimed in claim 20, wherein the determination unit determines whether the charging current for the battery part is controlled by the first control circuit or the second control circuit.

22. The battery charge control circuit as claimed in claim 20, wherein the charging conditions include charging the battery part at a constant current.

23. The battery charge control circuit as claimed in claim 20, wherein the charging conditions include charging the battery part at a constant voltage.

24. The battery charge control circuit as claimed in claim 20, further comprising:

a detecting unit which detects a charged state of the battery part; and

a completion determination unit which determines whether the charging of the battery part is completed from a determination result of the determination unit and a detection result of the detecting unit.

25. The battery charge control circuit as claimed in claim 20, wherein the power source is connected to a plurality of batteries, each of which is provided with the first control circuit.

26. A battery charge control circuit which controls a charging current so that a power source supplies power to both a battery part and a load, comprising:

a first control circuit which controls the charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions;

a second control circuit which controls the charging current so that power supplied from the power source does not exceed a predetermined capacity; and

a determination unit which determines whether the charging current for the battery part is controlled by the second control circuit.

27. The battery charge control circuit as claimed in claim 26, wherein the determination unit determines whether the charging current for the battery part is control by the first control circuit or the second control circuit.

28. The battery charge control circuit as claimed in claim 26, wherein the charging conditions include charging the battery part at a constant current.

29. The battery charge control circuit as claimed in claim 26, wherein the charging conditions include charging the battery part at a constant voltage.

30. The battery charge control circuit as claimed in claim 26, further comprising:

a detecting unit which detects a charged state of the battery part; and

a completion determination unit which determines whether the charging of the battery unit is completed from a determination result of the determination unit and a detection result of the detecting unit.

31. The battery charge control circuit as claimed in claim 26, wherein the power source is connected to a plurality of batteries, each of which is provided with the first control circuit.

32. A battery charging device for charging a battery part with power supplied from a power source, comprising a restricted state notifying unit which detects a restriction on a supply capacity of the power source, and outputs a notification that the supply capacity of the power source is restricted.

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

a first control circuit which controls a charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions; and

a second control circuit which controls the charging current for the battery part so that power supplied from the power source does not exceed a capacity;

wherein the restricted state notifying unit notifies that the charging current is controlled by the second control circuit.

34. The battery charging device as claimed in claim 32, wherein the power source supplies power to both the battery part and a load.

35. The battery charging device as claimed in claim 32, wherein the battery part includes a plurality of batteries connected in parallel.

36. A battery charging device which is connected to a power source for supplying a current to a load, and is connected to a battery part to be charged with power from the power source, said battery charging device comprising:

a current control unit which controls a current supplied from the power source to the battery part;

a control unit which detects a charged state of the battery part and controls the current control unit; and

a restricted state notifying unit which outputs a notification that a supply capacity of the power source is restricted.

37. The battery charging device as claimed in claim 36, wherein the battery part includes a plurality of batteries connected in parallel.

38. The battery charging device as claimed in claim 36, wherein the restricted state notifying unit detects the charging current for the battery part, and, in accordance with the charging current for the battery part, outputs the notification that the supply capacity of the power source is restricted.

39. The battery charging device as claimed in claim 38, wherein the restricted state notifying unit detects the charging current for the battery part, and, in accordance with a difference between the charging current for the battery part and a current demanded by the battery pack, outputs the notification that the supply capacity of the power source is restricted.

40. The battery charging device as claimed in claim 36, wherein the restricted state notifying unit detects a charging voltage for the battery part, and, in accordance with the charging voltage, outputs the notification that the supply capacity of the power source is restricted.

41. The battery charging device as claimed in claim 40, wherein the restricted state notifying unit detects the charging voltage for the battery part, and, in accordance with a difference between the voltage for the battery part and a voltage demanded by the battery part, outputs the notification that the supply power of the power source is restricted.

42. The battery charging device as claimed in claim 36, wherein the restricted state notifying unit detects an output current of the power source, and, in accordance with the output current of the power source, outputs the notification that the supply capacity of the power source is restricted.

43. The battery charging device as claimed in claim 42, wherein the restricted state notifying unit detects the output current of the power source, and, in accordance with a difference between the output current of the power source and a maximum current supplied from the power source, outputs the notification that the supply capacity of the power source is restricted.

44. The battery charging device as claimed in claim 36, wherein the restricted state notifying unit detects an output voltage of the power source, and, in accordance with the output voltage of the power source, outputs the notification that the supply capacity of the power source is restricted.

45. The battery charging device as claimed in claim 44, wherein the restricted state notifying unit detects the output voltage of the power source, and, in accordance with a difference between the output voltage of the power source and a predetermined reference voltage, outputs the notification that the supply capacity of the power source is restricted.

46. A battery charging device comprising:

a first control circuit which controls a current supplied from a power source so that a plurality of batteries are charged at a constant current and/or a constant voltage;

a second control circuit which controls charging currents for the plurality of batteries in accordance with an output of the power source; and

a determination unit which determines whether the charging currents for the plurality of batteries are controlled by the second control circuit.

47. The battery charging device as claimed in claim 46, wherein the first control circuit controls the current so that the plurality of batteries are charged at the constant current and/or the constant voltage.

48. A battery charging device which controls a charging current supplied from a power source to a battery part, said battery charging device comprising:

a first control circuit which controls the charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions;

a second control circuit which controls the charging current so that power supplied from the power source does not exceed a predetermined capacity; and

a determination unit which determines whether the charging current for the battery part is controlled by the second control circuit.

49. The battery charging device as claimed in claim 48, wherein the determination unit determines whether the charging current for the battery part is controlled by the first control circuit or the second control circuit.

50. The battery charging device as claimed in claim 48, wherein the charging conditions include charging the battery part at a constant current.

51. The battery charging device as claimed in claim 48, wherein the charging conditions include charging the battery part at a constant voltage.

52. The battery charging device as claimed in claim 48, further comprising:

a detecting unit which detects a charged state of the battery part; and

a completion determination unit which determines whether the charging of the battery unit is completed from a determination result of the determination unit and a detection result of the detecting unit.

53. The battery charging device as claimed in claim 48, wherein the power source is connected to a plurality of batteries, each of which is provided with the first control circuit.

54. A battery charging device which controls a charging current so that a power source supplies power to both a battery part and a load at the same time, comprising:

a first control circuit which controls the charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions;

a second control circuit which controls the charging current so that power supplied from the power source does not exceed a predetermined capacity; and

a determination unit which determines whether the charging current for the battery part is controlled by the second control circuit.

55. The battery charging device as claimed in claim 54, wherein the determination unit determines whether the charging current for the battery part is controlled by the first control circuit or the second control circuit.

56. The battery charging device as claimed in claim 54, wherein the charging conditions include charging the battery part at a constant current.

57. The battery charging device as claimed in claim 54, wherein the charging conditions include charging the battery part at a constant voltage.

58. The battery charging device as claimed in claim 54, further comprising:

a detecting unit which detects a charged state of the battery part; and

a completion determining unit which determines whether the charging of the battery unit is completed from a determination result of the determination unit and a detection result of the detecting unit.

59. The battery charging device as claimed in claim 54, wherein the power source is connected to a plurality of batteries, each of which is provided with the first control circuit.

60. A battery charge control method, comprising the steps of:

detecting a restriction on a supply capacity of a power source which supplies current to a load and charges a battery part; and

continuing the charging of the battery part when the supply capacity of the power source is restricted.

61. The battery charge control method as claimed in claim 60, wherein the battery part includes a plurality of batteries connected in parallel.

62. A battery charge control method, comprising the steps of:

charging a battery part at a constant current and/or a constant voltage obtained from a current supplied from a power source;

controlling a charging current for the battery part in accordance with an output of the power source; and

determining whether the charging current for the battery part is controlled in accordance with the output of the power source.

63. The battery charge control method as claimed in claim 62, wherein the determination result is outputted to the outside.

64. A battery charge control method, comprising the steps of:

charging a plurality of batteries connected in parallel by a current having a constant current level and/or a constant voltage and supplied from a power source;

controlling charging currents for the plurality of batteries in accordance with an output of the power source; and

determining whether the charging currents for the plurality of batteries are controlled in accordance with the output of the power source.

65. The battery charge control method as claimed in claim 64, wherein whether the charging current for each of the plurality of batteries is controlled is determined in accordance with an output current of the power source.

66. A battery charge control method, comprising the steps of:

detecting a restriction on a supply capacity of a power source;

outputting a notification, in accordance with a detected result, that the supply capacity of the power source is restricted;

a charging current for a battery part is controlled in accordance with the notification.

67. A battery charge control method, comprising the steps of:

controlling a current supplied from a power source so that a battery part is charged at a constant current and/or a constant voltage;

controlling a charging current for the battery part in accordance with an output of the power source; and

determining whether the charging current for the battery part is controlled in the step of controlling the charging current.

68. A battery charge control method, comprising the steps of:

controlling a current supplied from a power source so that a plurality of batteries are charged at a constant current and/or a constant voltage;

controlling charging currents for the plurality of batteries in accordance with an output of the power source; and

determining whether the charging currents for the plurality of batteries are controlled in the step of controlling the charging currents.

69. A battery charge control method for controlling a charging current supplied from a power source to a battery part, comprising the steps of:

controlling the charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions;

controlling the charging current so that power supplied from the power source does not exceed a predetermined capacity; and

determining whether the charging current for the battery part is controlled in the second step of controlling the charging current.

70. A battery charge control method for controlling a charging current so that a power source supplies power to a battery part and a load at the same time, said method comprising the steps of:

controlling a charging current for the battery part so that the battery part is charged in accordance with predetermined charging conditions;

controlling the charging current so that power supplied form the power source does not exceed a predetermined capacity; and

determining whether the charging current of the battery part is controlled in the second step of controlling the charging current.