A battery management apparatus, comprising: a voltage measuring unit configured to measure a voltage of a battery; a current measuring unit configured to measure a current of the battery; and a control unit configured to determine a state of charge based on at least one of the measured voltage and current during discharging of the battery, and a memory unit; characterised in that the control unit is configured to: determine if the voltage of the battery reached a preset discharge threshold voltage V threshold, when the voltage of the battery is determined to having reached the discharge threshold voltage V threshold, record an arrival time at which the voltage of the battery reached the discharge threshold voltage V threshold, and determine a discharge profile based on the state of charge, wherein data defining the discharge profile is recorded through previous experimentation using a predetermined level of constant current, obtain a maximum value of resistance change ratio (dR/dt) max preset for the discharge profile, predict a remaining time (t r) using the following Equation 1: t r = V min − V threshold I 0 dR dt max in which in the Equation 1, I 0 is the current of the battery measured at the arrival time, V min is the lower limit of discharge voltage, V threshold is the discharge threshold voltage, (dR/dt) max is the maximum value of resistance change ratio, and t r is the remaining time, and output a message notifying the predicted remaining time (t r). a voltage measuring unit configured to measure a voltage of a battery; a current measuring unit configured to measure a current of the battery; and a control unit configured to determine a state of charge based on at least one of the measured voltage and current during discharging of the battery, and a memory unit; characterised in that the control unit is configured to: determine if the voltage of the battery reached a preset discharge threshold voltage V threshold, when the voltage of the battery is determined to having reached the discharge threshold voltage V threshold, record an arrival time at which the voltage of the battery reached the discharge threshold voltage V threshold, and determine a discharge profile based on the state of charge, wherein data defining the discharge profile is recorded through previous experimentation using a predetermined level of constant current, obtain a maximum value of resistance change ratio (dR/dt) max preset for the discharge profile, predict a remaining time (t r) using the following Equation 1: t r = V min − V threshold I 0 dR dt max in which in the Equation 1, I 0 is the current of the battery measured at the arrival time, V min is the lower limit of discharge voltage, V threshold is the discharge threshold voltage, (dR/dt) max is the maximum value of resistance change ratio, and t r is the remaining time, and output a message notifying the predicted remaining time (t r). determine if the voltage of the battery reached a preset discharge threshold voltage V threshold, when the voltage of the battery is determined to having reached the discharge threshold voltage V threshold, record an arrival time at which the voltage of the battery reached the discharge threshold voltage V threshold, and determine a discharge profile based on the state of charge, wherein data defining the discharge profile is recorded through previous experimentation using a predetermined level of constant current, obtain a maximum value of resistance change ratio (dR/dt) max preset for the discharge profile, predict a remaining time (t r) using the following Equation 1: t r = V min − V threshold I 0 dR dt max in which in the Equation 1, I 0 is the current of the battery measured at the arrival time, V min is the lower limit of discharge voltage, V threshold is the discharge threshold voltage, (dR/dt) max is the maximum value of resistance change ratio, and t r is the remaining time, and output a message notifying the predicted remaining time (t r).