BATTERY MANAGEMENT SYSTEM, BATTERY PACK, ELECTRIC VEHICLE AND BATTERY MANAGEMENT METHOD

A battery management system according to the present disclosure is for a battery comprising a positive electrode material exhibiting a phase transition behavior in a predetermined capacity range and a negative electrode material having plateau characteristics over the predetermined capacity range. The battery management system includes a sensing unit to output sensing information indicating a voltage and a current of the battery, and a control unit. The control unit determines a voltage curve indicating a correspondence relationship between a capacity of the battery and the voltage of the battery based on the sensing information collected during constant current charging or constant current dischargingof the battery. The control unit determines a differential voltage curve based on the voltage curve. The control unit detects a peak of interest in a predetermined capacity range appearing in the differential voltage curve. The control unit determines a first capacity loss ratio of the battery based on a differential voltage of the peak of interest.