US 12,072,390 B2
Methods and apparatus for detecting battery cell imbalance
Hideo Kondo, Oizumi-machi (JP)
Assigned to SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC, Scottsdale, AZ (US)
Filed by SEMICONDUCTOR COMPONENTS INDUSTRIES, LLC, Phoenix, AZ (US)
Filed on Feb. 18, 2020, as Appl. No. 16/793,660.
Prior Publication US 2021/0255252 A1, Aug. 19, 2021
Int. Cl. G01R 31/396 (2019.01); G01R 31/3842 (2019.01); G01R 31/389 (2019.01); H01M 10/42 (2006.01); H01M 10/48 (2006.01); H02J 7/00 (2006.01)
CPC G01R 31/396 (2019.01) [G01R 31/3842 (2019.01); G01R 31/389 (2019.01); H01M 10/425 (2013.01); H01M 10/482 (2013.01); H02J 7/0048 (2020.01); H01M 2010/4278 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An apparatus capable of connecting to a battery pack, wherein the battery pack includes a first battery cell connected in series with a second battery cell, and has a first terminal and a second terminal, comprising:
a fuel gauge circuit configured to connect to the first terminal and the second terminal, and comprising:
a voltage detector configured to measure a total voltage of the battery pack;
a memory configured to store a first battery characteristic data indicating a relationship between open circuit voltage and capacity; and
a processor, in communication with the voltage detector and the memory, and configured to detect imbalance between the series-connected battery cells, comprising:
determine a first capacity based on the measured total voltage and the first battery characteristic data;
compute a first actual resistance of the battery pack using the measured total voltage and a first load current;
determine whether the computed first actual total resistance is equal to a theoretic resistance;
generating a first signal if the computed first actual total resistance is equal to the theoretic resistance, wherein the first signal indicates that the first and second battery cells are balanced;
generating a second signal if the computed first actual total resistance is not equal to the theoretic resistance, wherein the second signal indicates that the first and second battery cells are imbalanced;
compute a second actual resistance of the battery pack using the measured total voltage and a second load current; and
compute a second capacity of the first battery cell and a third capacity of the second battery cell using the computed first actual resistance, the computed second actual resistance, and a set of equations.