US 11,811,110 B2
System and method for determining state of charge for an electric energy storage device
Yang Song, West Linn, OR (US); Timothy J. McDonald, Portland, OR (US); and Thiago Groberg, Tigard, OR (US)
Assigned to ESS TECH, INC., Wilsonville, OR (US)
Filed by ESS TECH, INC., Tigard, OR (US)
Filed on Mar. 13, 2023, as Appl. No. 18/182,892.
Application 18/182,892 is a continuation of application No. 17/099,191, filed on Nov. 16, 2020, granted, now 11,631,872.
Application 17/099,191 is a continuation of application No. 16/179,665, filed on Nov. 2, 2018, granted, now 10,879,544, issued on Dec. 29, 2020.
Prior Publication US 2023/0216072 A1, Jul. 6, 2023
Int. Cl. H01M 8/04 (2016.01); H01M 8/04537 (2016.01); H01M 8/18 (2006.01); H01M 8/04955 (2016.01); H01M 8/04858 (2016.01)
CPC H01M 8/04611 (2013.01) [H01M 8/04582 (2013.01); H01M 8/04932 (2013.01); H01M 8/04955 (2013.01); H01M 8/188 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
operating an iron flow electric energy storage cell stack of N electric energy storage cell stacks;
determining a state of charge based on negative electrolyte based on a parameter indicative of plating efficiency at a negative electrode, the parameter further indicating a capacity of the iron flow electric energy storage cell stack to source and sink current;
in response to the iron flow electric energy storage cell stack changing from charging to discharging or in response to the iron flow electric energy storage cell stack changing from discharging to charging, decoupling the iron flow electric energy storage cell stack from the N electric energy storage cell stacks to determine an open circuit voltage of the iron flow electric energy storage cell stack; and
determining an adjusted state of charge based on the determined open circuit voltage.