BATTERY CHARGING SYSTEM AND METHOD

• US 20070188135A1
• Filed: 02/07/2007
• Published: 08/16/2007
• Est. Priority Date: 02/07/2006
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: Lenovo Singapore Pte Limited (Lenovo Group Ltd.)
• Inventors: Odaohhara, Shigefumi
• Granted Patent: US 7,714,533 B2
• Time in Patent Office: Days
• US Class Current: 320/114
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries

Abstract

A system and method are disclosed for charging battery packs. A battery pack connects to an external battery charger. A processor of the battery pack recognizes that the processor is connected the external battery charger. The external battery charger provides charging parameters to the battery pack. The processor sends charging parameters to the external battery in response to recognizing that the processor is connected to the external battery charger.

Claims

1. A charging system for a battery pack attachable to an electronic apparatus having an identification circuit, comprising:

an external battery charger comprising an identification circuit and a charging regulator whose charging characteristics are controlled in accordance with charging parameter values received from an external source; and

a battery pack comprising a battery cell and a processor capable of recognizing the identification circuit of the electronic apparatus and the identification circuit of the external battery charger and, upon recognizing the identification circuit of the external battery charger, sending the charging parameter values to the charging regulator.

2. The charging system according to claim 1, wherein the charging regulator comprises a voltage regulator and a current regulator that implement constant voltage constant current control mode and the charging parameter values comprise a charging voltage value and a charging current value.

3. The charging system according to claim 1, wherein the charging parameter values are sent to the external battery charger through a data line and a clock line to the processor.

4. The charging system according to claim 1, wherein the battery pack comprises a temperature measurement circuit including a thyristor, and each of the identification circuit of the electronic apparatus and the identification circuit of the external battery charger has a pull-up resistance capable of being connected to the temperature measurement circuit.

5. A battery pack attachable to an electronic apparatus comprising an identification circuit and capable of being charged by an external battery charger that includes an identification circuit and a charging regulator, the battery pack comprising:

a battery cell;

an external terminal connectable to the electronic apparatus and the external battery charger; and

a processor connectable to the identification circuit of any of the electronic apparatus and the external battery charger and upon recognizing the identification circuit of the electronic apparatus, sends information about charging of the battery cell to the electronic apparatus, and upon recognizing the identification circuit of the external battery charger, sends charging parameter values of the battery cell to the charging regulator.

6. The battery pack according to claim 5, wherein the charging parameter values are sent to the external battery charger through a data line connected to data terminal of the processor and a clock line connected to a clock terminal of the processor.

7. The battery pack according to claim 6, comprising a parameter setting section and a selector switch connected to the external terminal, the data terminal, the clock terminal, and the parameter setting section, wherein the processor controls the selector switch to connect the parameter setting section to the external terminal when the processor recognizes the identification circuit of the external battery charger, and to connect the data terminal and the clock terminal to the external terminal when the processor recognizes the identification circuit of the electronic apparatus.

8. The battery pack according to claim 5, comprising a charging switch which controls a charging current provided to the battery cell, wherein the processor turns off the charging switch when the processor does not recognize the identification circuit of the electronic apparatus and the identification circuit of the external battery charger.

9. The battery pack according to claim 5, wherein the processor sends the charging parameter values of the battery cell before turning on the charging switch when the battery pack is connected to the external battery charger.

10. The battery pack according to claim 5, comprising a thermistor, wherein the processor recognizes the electronic apparatus and the external battery charger on the basis of a voltage generated across the thermistor.

11. The battery pack according to claim 5, wherein the battery pack is compliant with a Smart Battery System specification.

12. A laptop personal computer to which a battery pack can be attached and which operates on power supplied from the battery pack, wherein the battery pack is a battery pack according to any of claims 5 to 11.

13. An external battery charger that charges a battery pack comprising a battery cell and a processor, the external battery charger attachable to an electronic apparatus and comprising:

an identification circuit that can be recognized by the processor when the battery pack is connected to the external battery charger; and

a charging regulator whose charging characteristics are controlled in accordance with charging parameters sent from the battery pack.

14. The external battery charger according to claim 13, comprising a transformer connected to an alternating current power supply.

15. The external battery charger according to claim 13, wherein the charging regulator receives the charging parameters through a data line and a clock line of the battery pack.

16. A method for using an external battery charger to charge a battery pack that is attachable to an electronic apparatus and includes a battery cell and a processor, the method comprising the steps of:

connecting the battery pack to the external battery charger;

recognizing that the processor is connected to the external battery charger;

providing charging parameters of the external battery charger to the battery pack;

sending by the processor the charging parameters to the external battery charger in response to the recognizing that the processor is connected to the external battery charger; and

charging by the external battery charger the battery cell in accordance with the charging parameters.

17. The charging method according to claim 16, wherein sending the charging parameters comprises sending the charging parameters through a data line and a clock line that transfer data compliant with a Smart Battery System specification.

18. The charging method according to claim 16, comprising the steps of:

turning off a charging switch that controls a charging circuit of the battery pack; and

turning on the charging switch subsequent to sending the charging parameters.