Intelligent serial battery charger

• US 20050083016A1
• Filed: 08/31/2004
• Published: 04/21/2005
• Est. Priority Date: 09/03/2001
• Status: Active Grant

• Current Assignee: GPE International Limited (Gold Peak Industries Limited)
• Original Assignee: GPE International Limited (Gold Peak Industries Limited)
• Inventors: Yau, Kwok Wong, Bai, Long, Li, Yiu Cheung
• Granted Patent: US 7,557,538 B2
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0018 using separate charge circuits

Abstract

A fast battery charger in which each one of the battery charging sections comprises a charging branch and a bypassing branch, the battery charger is provided with enhanced charging monitory and control circuitry and method for performance elevation with minimal additional hardware overhead.

Claims

1. Control means for a serial battery charger, said serial battery charger comprising a charging current source and a plurality of battery charging sections connected in series, each said battery charging section comprising first and second parallel branches, said first parallel branch comprising a bypassing switch which forms a low impedance bypassing shunt across said second parallel branch when actuated, said second parallel branch comprising an electronic isolation means connected in series with a pair of battery contact terminals for connecting a battery to said battery charging section for battery charging, said electronics isolation means when actuated substantially isolating said battery from said battery charging section, said electronic isolation means providing a low-impedance connection to said battery when de-actuated, wherein said control means repetitively actuates the bypassing switches of said plurality of battery charging sections for battery voltage measurements when batteries connected to said battery charging sections are still under battery charging conditions.

2. Control means according to claim 1, wherein said control means repetitively actuates said bypassing switches of said battery charging sections at a high frequency for battery voltage measurements.

3. Control means according to claims 2, wherein said control means causes actuation of the bypassing switch of a battery charging section in order to isolate a battery from said battery charging section battery to terminate charging of said battery.

4. Control means according to claims 1, wherein said control means causes actuation of the bypassing switch of a battery charging section in order to isolate a battery from said battery charging section battery to terminate charging of said battery.

5. Control means according to claims 1, wherein said control means actuates the bypassing switches of all the battery charging sections downstream of a battery charging section when the voltage of a battery connected to said battery charging section is measured, the actuation of said downstream bypassing switches connects the negative terminal of said battery to the reference ground of said battery charger.

6. Control means according to claim 5, wherein said battery charger comprises voltage measuring means for measuring battery voltages, each said voltages measuring means is connected to the positive battery terminal of a battery charging section, wherein, upon actuation of the bypassing switches downstream of a selected battery charging section, the voltage appearing at said positive battery terminal of said battery charging section is the voltage of said battery with reference to the ground of said battery charger.

7. Control means according to claim 6, wherein the open-circuit voltage of a battery connected to a selected battery charging section is measured when the bypassing switch of said battery charging section has been actuated.

8. Control means according to claims 2, wherein said control means actuates the bypassing switches of all the battery charging sections downstream of a battery charging section when the voltage of a battery connected to said battery charging section is measured, the actuation of said downstream bypassing switches connects the negative terminal of said battery to the reference ground of said battery charger.

9. Control means according to claim 8, wherein said battery charger comprises voltage measuring means for measuring battery voltages, each said voltages measuring means is connected to the positive battery terminal of a battery charging section, wherein, upon actuation of the bypassing switches downstream to a battery charging the voltage appearing at said positive battery terminal of said battery charging section is the voltage of said battery with reference to the ground of said battery charger.

10. A serial battery charger comprising a control means according to claim 1.

11. A serial battery charger of claim 10, wherein said control means comprising a micro-controller.

12. A serial battery charger of claim 10, wherein said bypassing switches are MOSFETs.

13. A serial battery charger of claim 10, wherein said battery contacts of said second parallel branches are downstream of said isolation means and the negative battery contact terminal of a battery charging section is in common with the common node of the first and second parallel branches of the next downstream charging section.

14. A serial battery charger comprising a control means according to claim 2.

15. A serial battery charger comprising a control means according to claim 3.

16. A serial battery charger comprising a control means according to claim 4.

17. A serial battery charger comprising a control means according to claim 5.

18. A serial battery charger comprising a control means according to claim 6.

19. A serial battery charger comprising a control means according to claim 7.

20. A serial battery charger comprising a control means according to claim 8.

21. A method of monitoring and controlling the charging of batteries for a serial battery charger, said serial battery charger comprising a charging current source and a plurality of battery charging sections connected in series, each said battery charging section comprising first and second parallel branches, said first parallel branch comprising a bypassing switch which forms a low impedance bypassing shunt across said second parallel branch when actuated, said second parallel branch comprising an electronic isolation means connected in series with a pair of battery contact terminals for connecting a battery to said battery charging section for battery charging, said electronics isolation means when actuated substantially isolating said battery from said battery charging section, said electronic isolation means providing a low-impedance connection to said battery when de-actuated, said method comprising the steps:

a) actuating the bypassing switches of said battery sections when batteries connected to said battery charging sections are still under battery charging conditions,

b) measuring the voltages of said batteries,

c) repeating steps a) and b) above until a battery is to be removed from the charging process,

d) isolating said battery from the said battery charging section to which said battery is connected and from the charging current source by actuating the bypassing switch of the battery charging section connected to said battery when the condition of said battery to be isolated fulfils a predetermined criterion.

22. A method according to claim 21, wherein steps a) and b) are repetitively performed at a high frequency.

23. A method according to claim 21, wherein steps a) and b) are repeated by actuating said bypassing switches at a frequency of about between 20-45 kHz.

24. A method according to claim 21, wherein said isolation means being upstream of said battery contact terminals, the method further comprising the step of actuating the bypassing switches of all battery charging sections downstream of a battery charging section in which the voltage of a battery connected to said battery charging section is being measured.

25. A method according to claim 24, wherein batteries connected to said downstream battery charging sections being electrically isolated from the charging current source upon actuation of said bypassing switches of said downstream battery charging sections, the actuation of said bypassing switches of said downstream battery charging sections simultaneously connecting the negative terminals of said batteries to the reference ground of said battery charger so that the voltage appearing at the positive terminals of the batteries connected to said downstream battery charging sections are the voltage of said batteries.

26. A charger with the monitoring and controlling method of claim 21.

27. A charger with the monitoring and controlling method of claim 22.

28. A charger with the monitoring and controlling method of claim 23.

29. A charger with the monitoring and controlling method of claim 24.

30. A charger with the monitoring and controlling method of claim 25.