US Patent 11214171 Mixed battery pack control

A vehicle system is provided with a battery and a controller. The battery includes a first module having a first capacity and a second module. The controller programmed to responsive to indication that the second module has been replaced by a new module with a second capacity that is greater than the first capacity for a corresponding state of charge (SOC), adjust a second SOC of the new module such that a maximum SOC value of the new module aligns with a maximum SOC value of the first module. The controller is further programmed to balance the first module and the new module separately.