US 12,146,918 B2
Method for determining the state of charge of the cells of a battery
Bruno Crouzevialle, Grenoble (FR)
Assigned to Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Paris (FR)
Appl. No. 17/627,595
Filed by Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Paris (FR)
PCT Filed Jul. 10, 2020, PCT No. PCT/EP2020/069677
§ 371(c)(1), (2) Date Jan. 14, 2022,
PCT Pub. No. WO2021/009086, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 1908115 (FR), filed on Jul. 18, 2019.
Prior Publication US 2022/0268847 A1, Aug. 25, 2022
Int. Cl. G01R 31/396 (2019.01); G01R 31/36 (2020.01); G01R 31/3835 (2019.01); H02J 7/00 (2006.01)
CPC G01R 31/3835 (2019.01) [G01R 31/3648 (2013.01); G01R 31/396 (2019.01); H02J 7/0048 (2020.01); H02J 7/007 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of determining, for each cell of a battery comprising a plurality of series-coupled cells, of an indicator QCi representative of the charge stored in the cell, the method comprising the steps of:
a) at the end of a phase of partial discharge or charge of the battery, measuring the voltage Ui across each cell of the battery;
b) calculating, for each cell, an interpolation coefficient Xi from a value C_rate representative of the battery discharge or charge rate during said partial discharge or charge phase, and from the voltages Ui measured at step a); and
c) determining, for each cell, from the interpolation coefficient Xi calculated for the cell at step b) and from a quantity Qcm representative of the charge stored in the battery, said indicator QCi representative of the charge stored in the cell,
wherein for each cell, the interpolation coefficient Xi calculated at step b) is a function of the voltage Ui of the cell measured at step a), of value C_rate, of a value Umin defined as being the lowest value of the voltages Ui measured at step a), of a value Umax defined as being the highest voltage of the voltages Ui measured at step b), and of a value Umoy defined as being the average of the voltages Ui measured at step b),
wherein the method is implemented by a management device integrated to the battery, to monitor the state of the different battery cells, to schedule possible battery maintenance operations, to optimize the use of the battery, or to prevent a possible malfunction.