US 12,255,472 B2
Switch duration setting for battery string state of charge balancing
Jun-mo Kang, Ann Arbor, MI (US); Charles W. Wampler, II, Birmingham, MI (US); and Dave G. Rich, Sterling Heights, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Jan. 14, 2022, as Appl. No. 17/575,846.
Application 17/575,846 is a continuation in part of application No. 17/541,115, filed on Dec. 2, 2021, abandoned.
Prior Publication US 2023/0179001 A1, Jun. 8, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01M 10/44 (2006.01); G01R 31/382 (2019.01); H01M 10/46 (2006.01); H01M 10/48 (2006.01); H02J 7/00 (2006.01)
CPC H02J 7/0014 (2013.01) [G01R 31/382 (2019.01); H01M 10/482 (2013.01); H02J 7/0024 (2013.01); H02J 7/0048 (2020.01); H01M 2220/20 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A battery system comprising:
a first positive terminal;
a second positive terminal;
a negative terminal;
switches;
two battery modules, wherein each of the two battery modules includes three strings of battery cells that are configured to, at different times be:
connected in series and to the first positive terminal via first ones of the switches;
connected in parallel and to the second positive terminal via second ones of the switches; and
disconnected from both of the first and second positive terminals; and
a switch control module configured to:
determine state of charges (SOCs) of the strings of battery cells, respectively;
determine periods of phases, respectively, based on the SOCs;
determine first periods for connecting ones of the strings in parallel during one of the phases;
divide the one of the phases into N equal length periods with N period endings, respectively, one of the N period endings being at an end of the one of the phases,
where N is an integer greater than one;
selectively decrease N;
when a number of the first periods that end closest to the one of the N period endings is at least a predetermined value, adjust the first periods to the respective closest ones of the N period endings; and
selectively actuate the switches based on the periods of the phases and the periods for the strings of battery cells.