Battery charging apparatus, battery pack and method for charging secondary battery

• US 6,534,953 B2
• Filed: 02/06/2001
• Issued: 03/18/2003
• Est. Priority Date: 02/08/2000
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shirakawa, Hiroshi
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/777,402
• Publication Number:
  US 20010015634A1
• Time in Patent Office: 770 Days
• Field of Search: 320/114, 320/107, 320/162, 429/7, 429/9, 429/96-100, 429/123
• US Class Current: 320/114
• CPC Class Codes: H02J 2310/22 The load being a portable electronic device
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

In order to reduce the charging time required for charging, there is provided a battery pack having a battery cell that supplies current to an electronic apparatus which is connected thereto or is charged by the supply of current from another power source, and a charge/discharge control section that controls the charging operation of the battery cell. The charge/discharge control section further includes a voltage sensing circuit that monitors the output voltage of an AC adapter, a protection circuit that senses the voltage between terminals of the battery cell and a control circuit that controls the charging operation. The battery pack is charged by using a charging apparatus having a charging adapter that has insertion slots for incorporating the battery pack and the AC adapter that generates the charge current.

Claims

1. A charging apparatus comprising:

a charge adapter having a plurality of battery insertion sections into which a battery pack having a charge control function to control charging of a rechargeable battery and/or an electronic apparatus incorporating said battery pack are respectively inserted; and

a power source for supplying a charging current, wherein

the charging current from said power source is supplied to said battery pack and/or to said electronic apparatus inserted into said plurality of battery insertion sections in parallel, and wherein

said charge control function starts a charging operation when an output voltage of said power source exceeds a predetermined threshold.

2. A battery pack comprising:

a rechargeable battery that is charged and discharged; and

a charge control section for sensing an output voltage of a charge power source to control a start and stop of charging, wherein

said battery pack is connected in parallel with another battery pack to said charge power source, and said charge control section of said battery pack senses a change in the output voltage of said charge power source due to charging of said another battery pack to control the start and stop of charging of said rechargeable battery of said battery pack, and wherein

said charge control section starts a charging operation when said output voltage of said charge power source exceeds a predetermined threshold.

3. The battery pack according to claim 2, wherein said rechargeable battery comprises a lithium ion battery.

4. A rechargeable battery charging method, wherein a plurality of battery packs containing a respective plurality of rechargeable batteries are charged, comprising:

a current supply step for supplying a charging current from a charge power source to said plurality of battery packs connected in parallel; and

a charge control step for sensing a change in an output voltage of said charge power source due to charging of at least one battery pack among said plurality of battery packs and for controlling a start and stop of charging other ones of said plurality of battery packs, wherein

wherein a charging operation is started when said output voltage is found to exceed a predetermined threshold in said charge control step.

5. The rechargeable battery charging method according to claim 4, wherein a charging operation is switched between a constant current charging operation and a constant voltage charging operation according to a voltage level of said plurality of battery packs as determined in said charge control step.

6. The rechargeable battery charging method according to claim 5, wherein said plurality of battery packs are charged individually in said constant current charging operation and said plurality of battery packs are charged simultaneously in said constant voltage charging operation.

7. The rechargeable battery charging method as described in claim 6 wherein said constant voltage charging operation for said plurality of battery packs is started when the voltage levels of all of said plurality of battery packs reach a predetermined voltage level.

8. The rechargeable battery charging method as described in claim 4 wherein said battery pack is provided with a lithium ion battery.