Battery SOC estimating apparatus and method

A battery state of charge estimating apparatus according to an embodiment of the present disclosure includes a charging and discharging unit for receiving a control signal including a C-rate and for charging and discharging a battery at the C-rate included in the control signal; a measuring unit for measuring a voltage of the battery in a charging and discharging process of the battery; and a control unit for transmitting the control signal to the charging and discharging unit, changing the C-rate included in the control signal whenever the voltage value measured by the measuring unit reaches a preset threshold value, and estimating SOC of the battery based on the result of comparing the changed C-rate with a preset cutoff value.