A mobile terminal apparatus including a battery, a temperature detection section that detects a temperature of the battery, a voltage detection section that detects a battery voltage of the battery, a discharge section discharges the battery, an illuminance detection section that detects an illuminance on the mobile terminal apparatus, and a control section. The control section determines whether to gradually discharge the battery in accordance with the detected illuminance or to rapidly discharge the battery, and the determination is made on the basis of the temperature detected from the temperature detection section and the battery voltage detected from the voltage detection section.