Charging control systems and circuits for recharging automobile batteries

• US 5,739,668 A
• Filed: 09/26/1996
• Issued: 04/14/1998
• Est. Priority Date: 12/05/1995
• Status: Expired due to Term

• Current Assignee: Suzuki Motor Corporation
• Original Assignee: Suzuki Motor Corporation
• Inventors: Nishikiori, Hidetaka
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/721,356
• Time in Patent Office: 565 Days
• Field of Search: 320/5, 320/9, 320/29, 320/30, 320/31, 320/32, 320/37, 320/38, 320/39, 320/48, 320/49, 320/6, 320/21
• US Class Current: 320/111
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A charging control unit 10 includes plug contacts 161, 162 and jack contacts 181, 182 for detecting connection of a charging plug 16 of a charger 12 to a receptacle 18, a current sensor 22 for detecting completion of charging from the charger 12 to a main battery 20, a main controller 26 for starting operation of a DC-to-DC converter 24 when connection of the charging plug 16 is detected by the plug contacts 161, 162 and the jack contacts 181, 182 and for terminating operation of the DC-to-DC converter 24 when completion of charging is detected by the current sensor 22, and a distribution circuit whereby operation of the DC-to-DC converter after completion of charging is finished.

Claims

1. A charging control unit of an electric automobile comprising first detection means for detecting connection of a charging plug of a charger to a receptacle, second detection means for detecting completion of charging from said charger to a main battery, and control means for starting operation of a DC-to-DC converter when connection of said charging plug is detected by said first detection means and for terminating the operation of said DC-to-DC converter when completion of charging is detected by said second detection means.

2. A charging control unit of an electric automobile according to claim 1, wherein said second detection means comprises a current sensor for detecting a charging current and said control means judges that completion of charging is detected when a predetermined time has passed after the charging current detected by said current sensor reduces to about zero.

3. A charging control unit of an electric automobile according to claim 1, wherein said control unit preserves data stored in a memory at least until the next charging operation after completion of charging.

4. An electric power system for an electric automobile comprising:

a motor for propelling the automobile;

a main battery for powering said motor;

a charging control unit which recharges said main battery in a controlled manner with power supplied by an external charger comprising first detection means for detecting connection of a charging plug of said external charger to a receptacle, second detection means for detecting completion of charging from said charger to said main battery, and control means for starting operation of a DC-to-DC converter when connection of said charging plug is detected by said first detection means and for terminating the operation of said DC-to-DC converter when completion of charging is detected by said second detection means; and

a driving circuit which drives said motor with power supplied from said main battery.

5. The electric automobile according to claim 4, further comprising an auxiliary battery for supplying power to said charging control unit.

6. The electric automobile according to claim 4 wherein said second detection means comprises a current sensor for detecting a charging current and said control means judges that completion of charging is detected when a predetermined time has passed after the charging current detected by said current sensor reduces to about zero.

7. The electric automobile according to claim 4, wherein said control unit preserves data stored in a memory at least until the next charging operation after completion of charging.

8. The electric automobile according to claim 7, wherein said preserved data includes data on input current flow into said main battery and those on temperature of the battery during recharging said main battery.

9. A power system for powering an electric automobile, comprising:

a motor for propelling the automobile;

a main battery for electrically powering said motor;

a charging control system for recharging said main battery in a controlled manner with power supplied from an external charger, said charging control system comprising;

a first detector for detecting connection of the external charger to the charging control system;

a second detector electrically connected to said main battery for detecting a predetermined electrical condition, said predetermined electrical condition corresponding to completion of charging of said main battery from the external charger;

a DC-to-DC converter operably associated with said main battery; and

a controller electrically connected with said first and second detectors and said DC-to-DC converter for starting operation of said DC-to-DC converter when connection of the external charger is detected by said first detector and for electrically disconnecting said DC-to-DC converter from said main battery when said main battery has been recharged; and

a driving circuit operably associated with said motor and said main battery, wherein said driving circuit drives said motor with power supplied from said main battery.

10. A power system according to claim 9, further comprising an auxiliary battery for supplying power to said charging control system, and wherein said main battery is electrically disconnected from said driving circuit during the recharging of said main battery.

11. A power system according to claim 9, wherein said charging control system further comprises a relay control unit and a plurality of electrical contacts configured to engage and disengage said DC-to-DC converter from said main battery and from the external charger corresponding to initiation and completion of charging.

12. A power system according to claim 10, wherein said charging control system further comprises electronic memory which stores data concerning the charging operation at least until the next subsequent charging operation.

13. A power system according to claim 10, wherein said charging control system is positioned in the automobile.

14. A charging control unit for recharging the main battery of an automobile battery in a controlled manner, comprising:

a first detector for detecting connection of the external charger to the charging control system;

a second detector electrically connected to said main battery for detecting a predetermined electrical condition, said predetermined electrical condition corresponding to completion of charging of said main battery from the external charger;

a DC-to-DC converter operably associated with the main battery; and

a controller electrically connected with said first and second detectors and said DC-to-DC converter for starting operation of said DC-to-DC converter when connection of said charging plug is detected by said first detector and for electrically disconnecting said DC-to-DC converter from said main battery upon completion of charging.

15. A control unit according to claim 14, further comprising an auxiliary battery for powering said charging control system.

16. A control unit according to claim 15, further comprising a relay control unit and a plurality of electrical contacts configured to engage and disengage said DC-to-DC converter from said main battery and the external charger corresponding to initiation and completion of said charging.

17. A control unit according to claim 16 wherein said controller includes electronic memory which stores data concerning the charging operation at least until the next subsequent charging operation.

18. A control unit according to claim 17, wherein said controller directs said relay control unit to disconnect said electrical contacts and terminate said charging operation a predetermined time after said second detector reaches a predetermined electrical value.

19. A control unit according to claim 16, wherein said control unit is positioned internal to the automobile.