A battery power detection device is disclosed that has a reduced circuit area and is able to achieve sufficiently high detection accuracy. The battery power detection device includes a temperature section detection unit that detects a temperature of the battery and detects one of plural predetermined temperature sections including the detected temperature, a current section detection unit that detects a current output from the battery and detects one of plural predetermined current sections including the detected current; and a power section detection unit that has plural voltage-power data tables including data indicating the relation between the voltage output from the battery and the remaining power sections of the battery. The power section detection unit selects one of the voltage-power data tables according to the detected temperature section and the detected current section, and detects one of the remaining power sections associated with a given voltage of the battery.