Electronic power unit with a battery and a compensator for calculating the actual charge capacity of the battery

• US 6,910,143 B2
• Filed: 04/02/2001
• Issued: 06/21/2005
• Est. Priority Date: 04/03/2000
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Tsurukawa, Noboru, Odaohhara, Shigefumi
• Primary Examiner(s): Browne, Lynne H.
• Assistant Examiner(s): YANCHUS III, PAUL B
• Application Number:
  US09/824,256
• Publication Number:
  US 20020144160A1
• Time in Patent Office: 1,541 Days
• Field of Search: 713/300, 713/310, 713/340, 320/106, 320/137
• US Class Current: 713/340
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision

Abstract

A main battery used as an electric power unit for a computer is provided with a memory that stores capacity information denoting the total capacity of a battery and compensation information representing the total capacity of the battery as a function of a battery charging cycle count. A CPU detects a cycle count of the battery according to an integrated charged capacity of the battery, thereby obtaining the total capacity with respect to this cycle count from the compensation information so as to compensate the capacity information according to the obtained total capacity.

Claims

1. An electric power unit comprising:

a battery;

an integrator that records a total charge received by said battery during different charging events, wherein an accumulation of said total charge that is equal to a total available capacity of the battery defines one charging cycle;

an information storage unit for storing compensation information representing the total available capacity of said battery as a function of the number of charging cycles undertaken by said battery;

a counter for counting said number of battery charging cycles; and

a compensator for obtaining a value for the total available capacity of said battery from said compensation information based on the number of charging cycles counted by said counter.

2. The electric power unit according to claim 1, wherein said different charging events are partial charges of said battery that are performed when said battery is not fully discharged.

3. The electric power unit according to claim 1, further comprising a temperature sensor for sensing a temperature,

wherein said information storage unit stores compensation information corresponding to said temperature;

and

said compensator compensates said capacity information according to said compensation information corresponding to said temperature sensed by said temperature sensor.

4. An electric power capacity information compensator employed for an electric power unit provided with a capacity information storage unit in which the total capacity of a built-in battery is stored, the electric power capacity information compensator comprising:

a compensation information storage unit for storing compensation information representing the total capacity of said battery as dependent on the number of charging cycles undertaken by said battery and being enabled to adjust said capacity information;

an integrator that records a total charge receive by said battery during different charging events, wherein an accumulation of said total charge that is equal to a total available capacity of the battery is deemed one charging cycle;

a counter for counting the number of cycles of said battery; and

a compensator for obtaining said total capacity corresponding to the number of cycles counted by said counter from said compensation information, thereby compensating said capacity information according to said obtained total capacity.

5. The electric power capacity information compensator according to claim 4;

wherein said different charging events are partial charges of said battery that are performed when said battery is not fully discharged.

6. The electric power capacity information compensator according to claim 4;

said compensator being operable to compensate said capacity information according to the total discharged capacity of said battery integrated until said battery capacity reaches a predetermined capacity and to compensate said total capacity denoted in said compensation information when said battery capacity reaches said predetermined capacity, according to said total discharged capacity of said battery.

7. The electric power capacity information compensator according to claim 4;

said compensator further including a temperature sensor for sensing a temperature;

said compensation information storage unit for storing compensation information corresponding to said temperature; and

said compensator being operable to compensate said capacity information according to compensation information corresponding to said temperature sensed by said temperature sensor.

8. A method for compensating battery capacity information in an electric power unit provided with a capacity information storage unit that stores capacity information denoting the total capacity of a built-in battery, comprising the steps of:

storing compensation information representing the total capacity of said battery with respect to the number of charging cycles undertaken by said battery;

recording a total charge received by said battery during different charging events, wherein an accumulation of said total charge that is equal to a total available capacity of the battery is deemed one charging cycle;

counting the number of charging cycles of said battery;

obtaining the total capacity of said battery corresponding to the number of counted cycles; and

compensating said capacity information according to said obtained total capacity.

9. The method according to claim 8, wherein said different charging events are partial charges of said battery that are performed when said battery is not fully discharged.

10. The method according to claim 9,

wherein said step of compensating said capacity information compensates said capacity information according to the total discharged capacity of said battery integrated until said battery capacity reaches a predetermined capacity and compensates the total capacity denoted in said compensation information when said battery capacity reaches said predetermined capacity, according to the total discharged capacity of said battery.

11. The method according to claim 8, comprising the further step of sensing a temperature,

wherein said step of storing compensation information stores compensation information corresponding to said temperature;

and said step of compensating said capacity information compensates said capacity information according to compensation information corresponding to said temperature sensed in said step.

12. A recording medium readable by a computer, said recording medium storing a program for compensating the capacity information in an electric power unit provided with a capacity information storage unit that stores capacity information representing the total capacity of a built-in battery, said program comprising program code executable by said computer to carry out the steps of:

storing compensation information representing the total capacity of said battery with respect to the number of charging cycles undertaken by said battery;

recording a total charge received by said battery during different charging events, wherein an accumulation of said total charge that is equal to a total available capacity of the battery is deemed one charging cycle;

counting the number of charging cycles of said battery;

obtaining the total capacity of said battery corresponding to the number of counted cycles; and

compensating said capacity information according to said obtained total capacity.

13. The recording medium according to claim 12, wherein said different charging events are partial charges of said battery that are performed when said battery is not fully discharged.

14. The recording medium according to claim 13;

wherein said step of compensating said capacity information compensates said capacity information according to the total discharged capacity of said battery integrated until said battery capacity reaches a predetermined capacity and compensates said total capacity denoted in said compensation information obtained in case said battery capacity reaches said predetermined capacity, according to said total discharged capacity of said battery.

15. The recording medium according to claim 12, comprising a further step of sensing a temperature,

wherein said step of storing compensation information stores compensation information corresponding to said temperature;

and

said step of compensating said capacity information compensates said capacity information according to compensation information corresponding to a temperature sensed in said step.

16. A computer, comprising:

a CPU;

a display device;

an input device;

a battery for supplying power in said computer;

an integrator that records a total charge received by said battery during different charging events, wherein an accumulation of said total charge that is equal to a total available capacity of the battery is deemed one charging cycle; and

an information storage unit for storing compensation information representing the variation in total available capacity of said battery as a function of the number of charging cycles undertaken by said battery.

17. The computer according to claim 16 further comprising:

a counter for counting said number of battery charging cycles; and

a compensator for obtaining a value for the total available capacity of said battery from said compensation information based on the number of charging cycles counted by said counter, and storing the value as capacity information in said information storage unit.