An electronic apparatus comprises a chargeable battery and a control unit configured to control power supply to a power supply unit of the apparatus and charging of the battery using the power received from an external apparatus. If a power amount that can be received from the external apparatus is sufficient to operate the apparatus but not sufficient to charge the battery, the control unit controls the predetermined voltage so as to reduce power consumption during operation of the apparatus, and if the received power is greater than the power consumption during operation of the apparatus, the control unit charges the battery using the power received from the external apparatus.