SWITCH DURATION SETTING FOR BATTERY STRING STATE OF CHARGE BALANCING

A battery system includes: two battery modules, each including three strings of battery cells that are configured to, at different times be: connected in series and to a first positive terminal via first ones of switches; connected in parallel and to a 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, respectively; determine periods of phases, respectively, based on the SOCs; determine first periods for connecting ones of the strings in parallel; divide one of the phases into N equal length periods; selectively decrease N; when a number of the first periods that end closest to one of N period endings is at least a predetermined value, adjust the first periods to the respective closest ones of the N period endings.