A battery apparatus is provided, in which even if a battery thereof is used under the low temperature environment or the battery has been charged/discharged many times, by changing and setting the end voltage that ends the discharge from the battery cell on the basis of the property of the battery, the dischargeable period can be extended. A battery apparatus for controlling an operation by detecting a charge/discharge state of a battery cell, which is chargeable/dischargeable, to supply a power source voltage to an electronic apparatus, includes: end voltage setting means for setting an end voltage that ends the discharge from the battery cell on the basis of a discharge property of the battery cell; and an end a voltage controller for varying and controlling a setting of the end voltage in accordance with a condition of the battery cell being used.