Systems and methods for cell balancing

• US 8,339,100 B2
• Filed: 05/04/2011
• Issued: 12/25/2012
• Est. Priority Date: 09/29/2009
• Status: Active Grant

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Li, Guoxing, Zhang, Wei, Chen, Songtao, Zhang, Chutao
• Primary Examiner(s): RAMADAN, RAMY O
• Application Number:
  US13/100,451
• Publication Number:
  US 20110241622A1
• Time in Patent Office: 601 Days
• Field of Search: 320/118, 320/119
• US Class Current: 320/118
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for balancing multiple battery cells which are grouped into multiple battery modules includes: obtaining cell parameters of the battery cells, respectively; calculating an average cell parameter for each of the battery modules according to the cell parameters; identifying a donator module and a receiver module from the battery modules based upon the average cell parameter; and transferring energy from the donator module to the receiver module to balance the battery cells.

Claims

1. A circuit for energy efficient and increased energy storage balancing of a plurality of battery cells of a rechargeable multi-cell battery pack, said circuit comprising:

a first switch array, wherein said battery cells are grouped into a first group of battery modules based upon configurations of said first switch array;

a second switch array, wherein said battery cells are grouped into a second group of battery modules based upon configurations of said second switch array, wherein each of said cells has a cell parameter, and wherein an average cell parameter for each battery module in said first and second groups is obtained by averaging a plurality of cell parameters of battery cells in said each battery module; and

a converter coupled between said first and second switch arrays,

wherein said first switch array is configured to select a donator module from said first group of battery modules according to said average cell parameter and deliver energy from said donator module to said converter, and wherein said second switch array is configured to select a receiver module from said second group of battery modules according to said average cell parameter and deliver said energy from said converter to said receiver module.

2. The circuit as claimed in claim 1, wherein said donator module has a maximum average cell parameter among a donator group of battery modules selected from said first group and further comprises a battery cell having a maximum cell parameter among all of said battery cells in said battery pack.

3. The circuit as claimed in claim 1, wherein said receiver module has a minimum average cell parameter among a receiver group of battery modules selected from said second group and further comprises a battery cell having a minimum cell parameter among all of said battery cells in said battery pack.

4. The circuit as claimed in claim 1, wherein said cell parameter comprises a state of charge (SOC) value, and wherein said average cell parameter comprises an average SOC value.