US 12,328,017 B2
System and method for charge balancing a battery pack over time
Paul Thomas Geantil, San Diego, CA (US); and Jaime Andrew Lerma, Murrieta, CA (US)
Assigned to FLUX POWER, INC., Vista, CA (US)
Filed by Flux Power, Inc., Vista, CA (US)
Filed on Nov. 19, 2021, as Appl. No. 17/531,268.
Claims priority of provisional application 63/116,846, filed on Nov. 21, 2020.
Prior Publication US 2022/0166228 A1, May 26, 2022
Int. Cl. H02J 7/00 (2006.01)
CPC H02J 7/0016 (2013.01) [H02J 7/0048 (2020.01); H02J 7/00712 (2020.01); H02J 7/005 (2020.01)] 16 Claims
OG exemplary drawing
 
9. A system for controlling charging of a plurality of battery cells comprising:
a cell voltage detector determining a top-of-charge voltage or bottom-of-charge voltage for each of the plurality of battery cells;
an imbalance circuit comparing the top-of-charge voltage or bottom-of-charge voltage for each of the plurality of battery cells to an imbalance threshold and determining a first battery cell of the plurality of battery cells is above the imbalance threshold by an imbalance amount;
a shunt control circuit determining an imbalance shunt time for the first battery cell based on the imbalance amount and controlling discharging the first battery cell for the imbalance shunt time toward the imbalance threshold; and
an imbalance histogram generator storing imbalance factors for plurality of cells in a histogram comprising histogram values, the imbalance histogram generator summing the histogram values from the histogram to form a sum and when the sum is greater than a predictive balancing trigger, the shunt control circuit setting a permanent shunt for use as the imbalance shunt time.