Rechargeable power supply system and method of protection against abnormal charging

• US 20020167294A1
• Filed: 03/20/2002
• Published: 11/14/2002
• Est. Priority Date: 05/08/2001
• Status: Active Grant

• Current Assignee: Acer, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Odaohhara, Shigefumi
• Granted Patent: US 6,661,200 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

An intelligent battery comprising a battery cell for charging and discharging; a voltage detection circuit for detecting voltage of the battery cell; a current detection circuit for detecting charging current; a charging-stop FET for stopping charging for the battery cell; and a CPU for activating the charging-stop FET based on voltage detected by the voltage detection circuit, wherein before the voltage reaches a voltage for activation of the charging-stop FET, when the charging current value detected for the battery capacity by the current detection circuit is larger than a reference, the CPU determines that an abnormal state occurs, and activates the charging-stop FET. The present invention provides, in part, a battery, which is safer even if dual accidental malfunctions occur.

Claims

1. A power supply system with a battery for supplying power to a main system, comprising:

a charging current measuring unit for measuring charging current for said battery;

a battery capacity calculating unit for calculating battery capacity of said battery;

and a detecting unit for detecting malfunction occurring in said battery based on a charging current value obtained by said charging current measuring unit and said battery capacity calculated by said battery capacity calculating unit.

2. The power supply system according to claim 1, further comprising a protection facility activating unit for activating a protection facility based on detection of malfunction occurrence by said detecting unit.

3. The power supply system according to claim 1, further comprising a notification unit for notifying said main system of malfunction based on detection of the malfunction occurrence by said detecting unit.

4. A computer device, comprising:

a main system for data processing; and

an intelligent battery for supplying power to said main system,

wherein said intelligent battery comprises;

a battery cell for charging and discharging,

a current detection circuit for detecting charging current for said battery cell; and

a CPU for calculating battery capacity by integrating charging current detected by said current detection circuit, and recognizing malfunction occurring in the battery based on charging current value detected by the current detection circuit and the calculated battery capacity.

5. The computer device according to claim 4, wherein said intelligent battery further comprises a protection circuit for performing stop operation according to instruction from the CPU based on recognition of malfunction occurrence by said CPU.

6. A battery for supplying power to an electric apparatus, comprising:

a charging current measuring unit for measuring charging current for a battery cell;

a battery capacity integration unit for integrating battery capacity for said battery cell; and

a malfunction detecting unit for detecting malfunction occurrence based on a charging current value measured by said charging current measuring unit and battery capacity integrated by said battery capacity integration unit.

7. The battery according to claim 6, wherein said malfunction detecting unit detects malfunction occurrence based on information in a table for malfunction detection showing the relation between battery capacity and malfunction detection current value.

8. The battery according to claim 6, wherein said malfunction detecting unit detects malfunction occurrence based on an equation representing the relation between battery capacity and charging current value, which equation is separately defined according to battery capacity.

9. A battery, comprising:

a battery cell;

a voltage detection circuit for detecting voltage for said battery cell;

a current detection circuit for detecting charging current for said battery cell;

a charging stop unit for stopping charging for said battery cell; and

a control unit for activating said charging stop unit based on voltage detected by said voltage detection circuit,

wherein before the voltage reaches a voltage for activating said charging stop unit, said control unit detects a malfunction state based on a charging current value detected by said current detection circuit, and activates the charging stop unit.

10. The battery according to claim 9, wherein said control unit calculates capacity of said battery cell, and if the charging current value detected for the calculated capacity by said current detection circuit is larger than a normal value, determines that a malfunction has occurred.

11. The battery cell according to claim 9, wherein said control unit, when connected to an apparatus with a charger employing constant-current/constant-voltage charging mode, activates said the charging stop unit in response to said detection of malfunction.

13. The method according to claim 12, wherein the protection facility is activated based on information specifying a reference value representing a charging current value at which a malfunction is detected for an integration capacity.

14. The method according to claim 12, wherein the protection facility is activated in a state where said integrated capacity is less than 100%.

16. The method according to claim 15, wherein the connection to said apparatus is recognized by receiving the ID of said device.

17. The method according to claim 15, wherein when it is determined that abnormal charging occurs, said apparatus is notified of the occurrence of abnormal charging.

12. A method for protecting a battery from abnormal charging, comprising:

measuring a charging current value for said battery;

calculating integrated capacity for said battery; and

activating a protection facility when the charging current value measured for the calculated integrated capacity is larger than a predetermined value.

15. A method for protecting an intelligent battery with a microcomputer from abnormal charging, comprising:

recognizing that said intelligent battery is connected to an apparatus with a charger for constant-current/constant-voltage charging;

measuring charging current value when said intelligent battery is charged while switching from constant-current charging to constant-voltage charging;

determining based on the measured charging current value whether abnormal charging occurs or not; and

aborting charging when it is determined that abnormal charging occurs.

18. A program of software-based code for enabling a microcomputer contained in a battery to perform:

a charging function for measuring charging current value for said battery;

a calculating function for calculating integrated capacity in said battery; and

a protecting function for activating a protection facility when the charging current value measured for the calculated integrated capacity is larger than a predetermined value.

19. A program for enabling a microcomputer contained in a battery to perform:

a function for recognizing that said battery is connected to an apparatus with a charger for constant-current/constant-voltage charging;

a function for measuring charging current value when said battery is charged while switching from constant-current charging to constant-voltage charging;

a function for determining based on the measured charging current value whether abnormal charging occurs or not; and

a function for aborting charging when it is determined that abnormal charging occurs.