System for battery formation, charging, discharging, and equalization

• US 6,291,972 B1
• Filed: 02/17/2000
• Issued: 09/18/2001
• Est. Priority Date: 02/17/1999
• Status: Expired due to Fees

• Current Assignee: Chaojiong Zhang
• Original Assignee: Chaojiong Zhang
• Inventors: Zhang, Chaojiong
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/505,611
• Time in Patent Office: 579 Days
• Field of Search: 320/118, 320/116, 320/117, 320/119, 320/120, 320/125, 320/126, 320/127, 320/138, 429/97, 429/98, 429/99, 429/100
• US Class Current: 320/118
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/446 Initial charging measures
• CPC Class Codes: H01M 50/209 adapted for prismatic or rectangular cells H01M50/216 takes precedence
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A circuit assembly for the formation and charging of secondary batteries, such as lithium ion and lithium-polymer cells, is provided. A parallel arrangement of cells eliminates the need for current regulation for each, thereby providing a mechanism for self-equalization of the cells configured in this way. Cells in parallel are governed by the same voltage profile, and each cell draws current from a voltage-regulating channel according to its state of health. A holder is also provided for connecting cells to the electronic instrument containing the voltage-regulating channel. This holder provides for reliable termination at the terminal tabs.

Claims

1. A circuit assembly for use in the formation of secondary cells comprising:

a. a master channel defining master voltage leads and master current leads;

b. means for coupling a first cell to the master channel across the master voltage leads in order to charge the first cell;

c. a slave channel defining slave voltage leads and slave current leads;

d. means for coupling a second cell to the slave channel across the slave voltage leads in order to charge the second cell; and

e. a control line from the master channel to the slave channel to control the output characteristics of the slave channel in order to charge the second cell equally with the first cell.

2. The circuit assembly of claim 1, further comprising means for coupling a third cell in parallel with the first cell.

3. The circuit assembly of claim 2, wherein the master channel includes a bipolar, output voltage-adjustable voltage regulator as an equalizer.

4. The circuit assembly of claim 1, wherein the master channel forms a plurality of secondary cells with a single voltage profile.

5. The circuit assembly of claim 1, wherein the assembly is adapted for charging rechargeable devices.

6. The circuit assembly of claim 2, further comprising means for coupling a plurality of cells in series or a parallel-series arrangement.

7. The circuit assembly of claim 1, wherein the assembly is adapted to recharge cells after use.

8. The circuit assembly for claim 1, further comprising a current limiter to provide over-current protection to the first cell.

9. The circuit assembly of claim 1, wherein the means for coupling a first cell comprises an individual flat cell holder.

10. The circuit assembly of claim 9, wherein the holder comprises:

a. an electrical contact for each of the anode and cathode of the first cell; and

b. a base on which the electrical contact for each of the anode and cathode is mounted.

11. The circuit assembly of claim 10, wherein the electrical contact includes electrical continuity to both the master voltage leads and master current leads.

12. The circuit assembly of claim 11, further comprising a protective cover adapted to be mounted to the base over the anode and cathode of the first cell.

13. The circuit assembly of claim 11, wherein the base is adapted to receive a range of sizes of cells.

14. The circuit assembly of claim 11, further comprising a cell interface block electrically coupled to the contact, the block having the capability for outfitting with a variety of connectors to connect the master channel to the holder.

15. The assembly of claim 1, adapted to be used in lithium polymer cell or flat cell formation.

16. A method of forming a plurality of secondary cells, comprising the steps of:

a. coupling a first secondary cell to a master channel in order to charge the first secondary cell;

b. coupling a second secondary cell to a slave channel in order to charge the second secondary cell;

c. providing power to the first and second secondary cells from the master and slave power supplies, respectively;

d. wherein the voltage of the slave channel in controlled by the master channel to charge the second secondary cell equally with the first secondary cell.

17. The method of claim 16, further comprising the step of mounting the first secondary cell in a holder.