Battery charging apparatus for series battery

• US 5,617,004 A
• Filed: 07/14/1995
• Issued: 04/01/1997
• Est. Priority Date: 07/18/1994
• Status: Expired due to Term

• Current Assignee: Akira Kaneko, VLT Incorporated (Vicor Corporation)
• Original Assignee: Integran, Inc.
• Inventors: Kaneko, Akira
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/502,085
• Time in Patent Office: 627 Days
• Field of Search: 320/6, 320/7, 320/15, 320/16, 320/17, 320/30, 320/35, 320/36, 320/39, 320/40, 320/48, 320/56
• US Class Current: 320/119
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A plurality of battery charging modules C, equal in number to a plurality of batteries B connected in series, are connected in series form a column of battery charging modules 6. Output terminals 7, 8 of this column 6 serve as the connecting terminals for a beginning terminal 2 and an ending terminal 3 of the series-connected column of batteries 1. A connecting point between consecutive batteries B connects to a junction point between consecutive battery charging modules C. This configuration enables the column of battery charging modules 6 to be connected with the column of batteries 1 and results in a set of parallel connections between the battery charging modules C and the corresponding batteries B. This enables current to flow at the same time from the battery charging modules C to each battery B connected in series therewith to charge batteries, and after the battery B with the largest balance of residual capacity is charged fully, the battery with the second largest balance of residual capacity is charged by the corresponding charging module C, and thereafter batteries are charged in the order of importance of residual capacity balance.

Claims

1. A battery charging apparatus for a column of batteries connected in series, comprising:

battery charging modules connected in series with the column of batteries and forming a column of battery charging modules, the number of said modules being the same as the number of batteries which form the column of batteries, adjacent series-connected battery charging modules being connected to one another via respective output terminals of different polarity, the terminals of different polarity joining at a respective junction point, the column of battery charging modules having two column output terminals,

said column output terminals of said column of battery charging modules being respectively connected with a beginning and an ending terminal of the column of batteries,

wherein the respective junction point between adjacent series-connected battery charging modules is connected to a junction between adjacent series-connected batteries, such that each battery has a corresponding respective battery charging module, and

wherein each of said battery charging modules further includes;

a detector for detecting a charged state of a corresponding battery,

a control unit for outputting a control signal which varies based upon the charged state of the corresponding battery detected by said detector, and

a charging voltage supply unit connected to said control unit for charging the corresponding battery, each battery charging module supplying a continuously variable charging voltage from its charging voltage supply unit to the corresponding battery in accordance with the control signal.

2. The battery charging apparatus described in claim 1 wherein the detector of each of said battery charging modules is a temperature detector for detecting a temperature around an external surface of the corresponding battery, said control signal varying in accordance with the temperature detected by said temperature detector.

3. The battery charging apparatus described in claim 1, further comprising a voltmeter connected between the output terminals of each battery charging module for displaying the voltage across said output terminals.

4. The battery charging apparatus described in claim 2, further comprising a voltmeter connected between the output terminals of each battery charging module for displaying the voltage across said output terminals.

5. The battery charging apparatus described in claim 1, wherein the detector of each of said battery charging modules is a temperature detector for detecting a temperature on an external surface of the corresponding battery, said control signal varying in accordance with the temperature detected by said temperature detector.

6. The battery charging apparatus described in claim 5, further comprising a voltmeter connected between the output terminals of each battery charging module for displaying the voltage across said output terminals.

7. The battery charging apparatus described in claim 1, wherein adjacent series-connected batteries connect to the junction via respective output terminals of different polarity.

8. The battery charging apparatus described in claim 1, further comprising:

a pair of first cables connecting said column output terminals to the beginning and ending terminals of the column of batteries, respectively; and

a smaller cable connecting a respective junction point between adjacent series-connected battery charging modules to a respective junction between adjacent series-connected batteries, said smaller cable being of smaller diameter relative to said first cable.