US 12,085,619 B2
Method for estimating battery state of charge and battery management system applying the same
Yong Chul Sung, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/435,822
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed Sep. 5, 2020, PCT No. PCT/KR2020/013043
§ 371(c)(1), (2) Date Sep. 2, 2021,
PCT Pub. No. WO2021/085869, PCT Pub. Date May 6, 2021.
Claims priority of application No. 10-2019-0137548 (KR), filed on Oct. 31, 2019.
Prior Publication US 2022/0155380 A1, May 19, 2022
Int. Cl. G01R 31/3842 (2019.01); G01R 31/36 (2020.01); H01M 10/42 (2006.01); H01M 10/44 (2006.01)
CPC G01R 31/3842 (2019.01) [G01R 31/3648 (2013.01); H01M 10/4207 (2013.01); H01M 10/425 (2013.01); H01M 10/441 (2013.01); H01M 2010/4271 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for estimating a state of charge (SOC) of a battery module assembly including a plurality of battery modules respectively including a plurality of battery cells, the method comprising:
receiving a battery current from a current sensor, the battery current being an amount of current flowing to or from the battery module assembly;
comparing the battery current and a threshold current;
selecting one of a first method for estimating a state of charge and a second method for estimating a state of charge, according to a result of the comparing, the second method being different from the first method;
estimating a current SOC of the battery cells according to the selected one of the first method and the second method for estimating a state of charge; and
estimating the SOC of the battery module assembly by combining the estimated current SOC of the battery cells,
wherein the estimating of the current SOC of the battery cells includes:
if the battery current is less than or equal to the threshold current, estimating the current SOC for the battery cells based on current cell voltages or a previous SOC of a plurality of battery cells respectively in each battery module, among the plurality of battery modules, according to the first method for estimating a state of charge; and
if the battery current is greater than the threshold current, estimating the current SOC of the battery cells based on a SOC deviation from a representative previous SOC value respectively of each battery module, among the plurality of battery modules, according to the second method for estimating a state of charge.