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

摘要

A battery management system according to the present invention includes a memory configured to store a first open voltage curve, a second open voltage curve, and a third open voltage curve; a voltage sensor configured to measure a battery voltage that is a voltage across the battery; and a control circuit operatively coupled to the memory and the voltage sensor. The first open-circuit voltage curve defines a first relationship between an open-circuit voltage of the battery upon discharging of the battery and a state of charge. The second open-circuit voltage curve defines a second relationship between an open-circuit voltage of the battery and a state of charge during charging of the battery. The third open circuit voltage curve defines a third relationship representing an average of the first relationship and the second relationship. The control circuit is configured to, upon receiving a key-off signal, block the flow of current through the battery such that the battery is put into a dormant state. The control circuit is configured to, if the battery is being discharged when the key-off signal is received, based on the battery voltage and the first open circuit voltage curve measured every predetermined time from a first time point to a second time point, and estimate the state of charge of the battery every hour. The first time point is a time point at which a first waiting time elapses from when the key-off signal is received. The second time point is a time point at which a first switching time has elapsed from when the key-off signal is received.