US 12,146,917 B2
Determination and utilization of over-predictive battery state of charge
Jeffrey A. Bednar, South Lyon, MI (US); Justin Bunnell, Farmington Hills, MI (US); and Xavier Camacho Tardi, Pontiac, MI (US)
Assigned to GM Global Technology Operations LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Dec. 17, 2021, as Appl. No. 17/554,496.
Prior Publication US 2023/0194615 A1, Jun. 22, 2023
Int. Cl. G01R 31/367 (2019.01); G01R 31/36 (2020.01); G01R 31/3835 (2019.01)
CPC G01R 31/367 (2019.01) [G01R 31/3648 (2013.01); G01R 31/3835 (2019.01)] 20 Claims
OG exemplary drawing
 
1. A battery system comprising:
a multi-cell rechargeable energy storage system (RESS) having a plurality of battery cells; and
an electronic controller connected to the RESS and configured to process data for the plurality of battery cells;
wherein:
the electronic controller is programmed with a battery cell open circuit voltage (OCV) versus state of charge (SOC) data table;
the OCV versus SOC data table is used to calculate a peak OCV movement for a representative battery cell at predetermined capacity and maximum discharge or charge rate; and
the electronic controller is configured to:
acquire voltage data for one of the plurality of battery cells during active cycling of the RESS;
pass the acquired voltage data through a first-order lag filter algorithm to generate an overpredicted OCV for the one of the plurality of battery cells, such that the overpredicted OCV is calibrated to advance slower in discharge and advance faster in charge than the calculated peak OCV movement by a predetermined margin;
determine an overpredicted SOC value for the one of the plurality of battery cells in the OCV versus SOC data table using an OCV value from the overpredicted OCV, wherein that the overpredicted SOC value exceeds a true SOC for the one of the plurality of battery cells by the predetermined margin; and
regulate the RESS using the determined overpredicted SOC value for the one of the plurality of battery cells.