Embodiments of the present disclosure provide a battery power estimating method. The method includes: performing a discharge operation of a battery; detecting, by an impedance component, a plurality of current values generated by the discharge operation of the battery during a time range, wherein the impedance component is coupled to a discharge path of the battery; obtaining a first average current value of the current values; obtaining a value distribution status of the current values; and estimating a remaining power of the battery according to the first average current value, the value distribution status and an initial power of the battery.