System for balancing a plurality of battery pack system modules connected in series

• US 7,880,434 B2
• Filed: 04/02/2009
• Issued: 02/01/2011
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: Southwest Electronic Energy Corporation (Ultralife Corporation)
• Original Assignee: Southwest Electronic Energy Corporation (Ultralife Corporation)
• Inventors: White, David Allen, Benckenstein, Claude Leonard Jr.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US12/417,435
• Publication Number:
  US 20090289599A1
• Time in Patent Office: 670 Days
• Field of Search: 320/112, 320/116, 320/119, 320/124, 320/128, 320/132, 320/136, 320/122
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

A system for balancing a plurality of battery pack system modules connected in series comprising: a plurality of battery pack system modules, wherein a high charge module of the plurality of battery pack system modules has a charge greater than a that of other modules. At least one zener diode connected in series with a current limiting resistor is connected in parallel to the plurality of battery pack system modules. A power source is in communication with a disconnect circuit of at least one of the battery pack system modules. The disconnect circuit is actuated when the battery pack system module reaches a predetermined state of charge. The zener diode enables current from the power source to bypass charged battery pack system modules to charge other battery pack system modules.

Claims

1. A system for balancing a plurality of battery pack system modules connected in series, the system comprising:

a plurality of battery pack system modules connected in series, wherein a high charge module of the plurality of battery pack system modules has a charge greater than a charge for other modules of the plurality of battery pack system modules connected in series;

at least one zener diode connected in series with a current limiting resistor, wherein the at least one zener diode is disposed between the high charge module and an adjacent battery pack system module of the plurality of battery pack system modules, wherein each of the battery pack system modules comprises a disconnect circuit that has a charge switch that can be opened to prevent further charging of all of the battery pack system modules, wherein the at least one zener diode is in communication with the disconnect circuit of at least one of the plurality of battery pack system modules;

a plurality of controller assemblies, wherein each battery pack system module comprises a controller assembly from the plurality of controller assemblies and a balancing circuit in communication with the controller assembly disposed within the battery pack system module, wherein the controller assembly disposed in the battery pack system module is in communication with the disconnect circuit disposed in the battery pack system module, and wherein each controller assembly is adapted to open the charge switch of the associated disconnect circuit when the associated battery pack system module reaches a predetermined state of charge, and to balance the associated battery pack system module with the other battery pack system modules within the plurality of battery pack system modules by discharging the battery pack system module having the open charge switch;

a power source in communication with the disconnect circuits, wherein at least one of the disconnect circuits is actuated when the at least one of the plurality of battery pack system modules reaches a predetermined state of charge, and wherein the disconnect circuit stops current from the power source to the plurality of battery pack system modules;

wherein current from the power source is limited by the current limiting resistor; and

wherein the at least one zener diode enables current from the power source to bypass at least one of the plurality of battery pack system modules at the predetermined state of charge to charge at least one other battery pack system module.

2. The system of claim 1, wherein each battery pack system module further comprises a protective diode connected to a plurality of cells connected in series and to the disconnect circuit in the battery pack system module, wherein the protective diode is a reverse voltage protection diode or a bypass diode.

3. The system of claim 1, wherein each disconnect circuit further comprises a discharge switch.

4. The system of claim 1, wherein the controller assembly further comprises configuration memory with design parameters and computer instructions for instructing the processor to customize specifications of the battery pack system module using the design parameters.

5. The system of claim 1, further comprising a display device in communication with each of the controller assemblies, wherein the controller assemblies further comprise computer instructions for instructing the processor to display the state of charge of each battery pack system module on the display device.

6. The system of claim 5, wherein the display device comprises a member of the group consisting of:

a plurality of light emitting diodes, a liquid crystal display, a plasma display, and combinations thereof.

7. The system of claim 5, wherein each of the controller assemblies further comprise computer instructions for instructing the processor to display an absolute state of charge for each battery pack system module by counting coulombs.

8. The system of claim 1, wherein the power source comprises a rechargeable battery.

9. The system of claim 8, wherein the rechargeable battery comprises a member of the group consisting of:

a lithium ion battery, a nickel cadmium battery, a nickel metal hydride battery, a lead acid battery, and combinations thereof.

10. The system of claim 1, wherein at least one of the battery pack system modules comprises at least one capacitor, at least one supercapacitor, at least one other electrochemical cell, or combinations thereof.

11. The system of claim 1, wherein at least one of the battery pack system modules comprises a plurality of battery pack system modules connected in parallel.

12. The system of claim 11, wherein the plurality of battery pack system modules connected in parallel are further connected in series.

13. The system of claim 12, wherein at least one of the plurality of battery pack system modules is individually replaceable.

14. The system of claim 1, wherein at least one of the battery pack system modules is individually replaceable.

15. A system for balancing a plurality of battery pack system modules connected in series, the system comprising:

a plurality of battery pack system modules connected in series, wherein a high charge module of the plurality of battery pack system modules has a charge greater than a charge for other modules of the plurality of battery pack system modules connected in series;

wherein each battery pack system module of the plurality of battery pack system modules comprises;

at least one balancing circuit comprising a shunt resistor and a bypass switch, wherein the at least one balancing circuit is in communication with a plurality of cells connected in series;

at least one disconnect circuit comprising a charge switch, wherein the at least one disconnect circuit is in communication with the plurality of cells;

a controller assembly in communication with the plurality of cells connected in series, the controller assembly comprising;

a digital controller comprising a processor;

means for monitoring and measuring parameters for the plurality of cells to determine a state of charge for each cell of the plurality of cells;

computer instructions for instructing the processor to actuate and de-actuate the at least one balancing circuit, the at least one disconnect circuit, or combinations thereof, responsive to the parameters for the plurality of cells;

computer instructions for instructing the processor to actuate and de-actuate the charge switch of the at least one disconnect circuit when one of the plurality of battery pack system module reaches a predetermined state of charge;

computer instructions for instructing the processor to actuate and de-actuate the bypass switch of at least one balancing circuit to at least partially discharge the associated battery pack system module when the associated battery pack system module reaches the predetermined state of charge; and

a power source in communication with the at least one disconnect circuit, wherein the at least one disconnect circuit and the at least one balancing circuit are actuated when the associated battery pack system module reaches the predetermined state of charge enabling at least partial discharge of the associated battery pack system module, wherein the at least one disconnect circuit stops current from the power source to the plurality of battery pack system modules.

16. A system for balancing a plurality of battery pack system modules connected in series, the system comprising:

a. a first battery pack system module comprising;

i. a first plurality of cells;

ii. a first balancing circuit in communication with the first plurality of cells;

iii. a first disconnect circuit in communication with the first plurality of cells, wherein the first disconnect circuit comprises a first charge switch adapted to be opened to prevent charging of the first battery pack system module and any other battery pack system modules connected in series with the first battery pack system module;

iv. a first control assembly in communication with the first plurality of cells, the disconnect circuit, and the first balancing circuit, wherein the first control assembly is adapted to open the first charge switch to prevent charging of the first battery pack system module and any series connected battery system modules, and actuate the first balancing circuit to discharge current from the first battery pack system module when the first battery pack system module reaches a predetermined state of charge;

b. a second battery pack system module comprising;

i. a second plurality of cells

ii. a second balancing circuit in communication with the second plurality of cells;

iii. a second disconnect circuit in communication with the second plurality of cells, wherein the second disconnect circuit comprises a second charge switch adapted to be opened to prevent charging of the second battery pack system module and any other battery pack system modules connected in series with the second battery pack system module;

iv. a second control assembly in communication with second plurality of cells, the disconnect circuit, and the second balancing circuit, wherein the second control assembly is adapted to open the second charge switch to prevent charging of the second battery pack system module and any series connected battery system modules, and actuate the second balancing circuit to discharge current from the second battery pack system module when the second battery pack system module reaches a predetermined state of charge; and

c. a charger power source in communication with the series connected first and second battery pack system modules.