Charging apparatus for controlling supplement of electric current to a rechargeable battery

• US 5,880,576 A
• Filed: 02/21/1997
• Issued: 03/09/1999
• Est. Priority Date: 02/21/1996
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nagai, Shinji
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US08/803,860
• Time in Patent Office: 746 Days
• Field of Search: 320/138, 320/160, 320/112, 320/122
• US Class Current: 320/138
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0071 with a programmable schedule

Abstract

A charging apparatus for charging a rechargeable battery, such as a Lithium-ion type battery. The charging apparatus is provided with a first current stabilized unit and a second current stabilized unit for stabilizing two different levels of electric current. The first current stabilized unit provides a relatively large electric current for charging the battery package. The second current stabilized unit provides a relatively small electric current for charging the battery package. A switching unit is provided for switching a connection of the first and second current stabilized units to provide current to the rechargeable battery. A detection unit is provided for detecting an electric voltage at terminals of the rechargeable battery. The detection unit controls the switching unit so as to switch connection of the first and second current stabilized units to provide current to the rechargeable battery based on the detected voltage. A management unit may further store charging conditions for further controlling the switching unit.

Claims

1. A charging apparatus for providing electric power to a rechargeable battery, comprising:

a first current stabilized unit providing a first electric current to said rechargeable battery;

a second current stabilized unit providing a second electric current to said rechargeable battery, wherein said second electric current is less than said first electric current;

a switching unit switching a connection of said first and second current stabilized units to provide current to said rechargeable battery; and

a detection unit detecting an electric voltage of a terminal of said rechargeable battery, and for controlling the switching unit so as to switch the connection of said first and second current stabilized units to provide current to said rechargeable battery from the first and the second current stabilized units until a first detection of a predetermined electric voltage of the terminal, then switching to disconnect said second current stabilizing unit at the first detection of said predetermined electric voltage of the terminal, and to then switch to provide current from only said second current stabilizing unit on a second detection of said predetermined electric voltage of the terminal.

2. A charging apparatus as recited in claim 1, wherein said rechargeable battery is a Lithium-ion battery.

3. A charging apparatus as recited in claim 1, wherein said switching unit disconnects both of said first and second current stabilized units from providing current to said rechargeable battery when said detection unit detects a predetermined electric voltage of said rechargeable battery is reached for a third time.

4. A charging apparatus for providing electric power to a rechargeable battery, comprising:

a first current stabilized unit providing a first electric current to said rechargeable battery;

a second current stabilized unit providing a second electric current to said rechargeable battery, wherein said second electric current is less than said first electric current;

a switching unit switching a connection of said first and second current stabilized units to provide current to said rechargeable battery;

a detection unit detecting an electric voltage of a terminal of said rechargeable battery, and for controlling the switching unit so as to switch the connection of said first and second current stabilized units to provide current to said rechargeable battery; and

a management unit managing said switching unit so as to switch connection of said first and second current stabilized units based on predetermined conditions within said managing unit and the detected electric voltage of the terminal.

5. A charging apparatus as recited in claim 4, wherein said management unit stores said predetermined conditions for controlling a switching operation of the switching unit.

6. A charging apparatus as recited in claim 4, wherein said management unit receives said predetermined conditions from an external unit of the charging apparatus.

7. A charging apparatus as recited in claim 4, wherein said apparatus further comprising:

an output providing information of a charging process of the rechargeable battery.

8. A charging apparatus as recited in claim 4, wherein said rechargeable battery is a Lithium-ion battery.

9. A charging apparatus as recited in claim 4, wherein said detection means detects a rated electric voltage of said rechargeable battery.

10. A charging apparatus as recited in claim 4, wherein said switching means disconnects both of said first and second current stabilized means from providing current to said rechargeable battery when said detection means detects a predetermined electric voltage of said rechargeable battery is reached for a predetermined time.

11. A charging apparatus for providing electric power to a rechargeable battery, comprising:

a first current stabilized means for providing a first electric current to said rechargeable battery;

a second current stabilized means for providing a second electric current to said rechargeable battery, wherein said second electric current is less than said first electric current;

a switching means for switching a connection of said first and second current stabilized means to provide current to said rechargeable battery; and

a detection means for detecting an electric voltage of a terminal of said rechargeable battery, and for controlling the switching means so as to switch the connection of said first and second current stabilized means to provide current to said rechargeable battery from the first and the second current stabilized means until a first detection of a predetermined electric voltage of the terminal, then switching to disconnect said second current stabilizing means at the first detection of said predetermined electric voltage of the terminal, and to then switch to provide current from only said second current stabilizing means on a second detection of said predetermined electric voltage of the terminal.

12. A charging apparatus as recited in claim 11, wherein said rechargeable battery is a Lithium-ion battery.

13. A charging apparatus as recited in claim 11, wherein said switching means disconnects both of said first and second current stabilized means from providing current to said rechargeable battery when said detection unit detects a predetermined electric voltage of said rechargeable battery is reached for a third time.

14. A charging apparatus for providing electric power to a rechargeable battery, comprising:

a first current stabilized means for providing a first electric current to said rechargeable battery;

a second current stabilized means for providing a second electric current to said rechargeable battery, wherein said second electric current is less than said first electric current;

a switching means for switching a connection of said first and second current stabilized means to provide current to said rechargeable battery;

a detection mean for detecting an electric voltage of a terminal of said rechargeable battery, and for controlling the switching means so as to switch the connection of said first and second current stabilized means to provide current to said rechargeable battery; and

a management means for managing said switching means so as to switch connection of said first and second current stabilized means based on predetermined conditions within said managing means and the detected electric voltage of the terminal.

15. A charging apparatus as recited in claim 14, wherein said management means stores said predetermined conditions for controlling a switching operation of the switching means.

16. A charging apparatus as recited in claim 14, wherein said management means receives said predetermined conditions from an external means of the charging apparatus.

17. A charging apparatus as recited in claim 14, wherein said apparatus further comprising:

an output providing information of a charging process of the rechargeable battery.

18. A charging apparatus as recited in claim 14, wherein said rechargeable battery is a Lithium-ion battery.

19. A charging apparatus as recited in claim 14, wherein said detection means detects a rated electric voltage of said rechargeable battery.

20. A charging apparatus as recited in claim 14, wherein said switching means disconnects both of said first and second current stabilized means from providing current to said rechargeable battery when said detection means detects a predetermined electric voltage of said rechargeable battery is reached for a predetermined time.