An electronic device comprising: a housing; a power interface configured to be connected to an external power source through the housing; a power management module electrically connected to the power interface; at least one battery configured to be charged by an external power supplied through the power management module; a processor operatively connected to the power interface; and a memory configured to store instructions, wherein, when the instructions are executed, the processor is configured to: actively lower a voltage value of the at least one battery according to set values in a stepwise manner in response to a connection holding time between the power interface and the external power source elapsing section-wise threshold times after a voltage of the at least one battery reaches the voltage value in a state in which the external power source is connected to the power interface; and control the power management module to block the external power supplied to the at least one battery when the voltage of the at least one battery is above or at the voltage value, wherein at the voltage value, the at least one battery is considered to be fully charged such that the at least one battery is not charged anymore, and wherein the processor is further configured to: when lowering the voltage value of the at least one battery to the set values in the stepwise manner, control the power management module to switch the at least one battery to a discharge state; and control the power management module to release the discharge state of the at least one battery when the voltage of the at least one battery reaches the voltage value, which is lowered according to the set values. a housing; a power interface configured to be connected to an external power source through the housing; a power management module electrically connected to the power interface; at least one battery configured to be charged by an external power supplied through the power management module; a processor operatively connected to the power interface; and a memory configured to store instructions, wherein, when the instructions are executed, the processor is configured to: actively lower a voltage value of the at least one battery according to set values in a stepwise manner in response to a connection holding time between the power interface and the external power source elapsing section-wise threshold times after a voltage of the at least one battery reaches the voltage value in a state in which the external power source is connected to the power interface; and control the power management module to block the external power supplied to the at least one battery when the voltage of the at least one battery is above or at the voltage value, wherein at the voltage value, the at least one battery is considered to be fully charged such that the at least one battery is not charged anymore, and wherein the processor is further configured to: when lowering the voltage value of the at least one battery to the set values in the stepwise manner, control the power management module to switch the at least one battery to a discharge state; and control the power management module to release the discharge state of the at least one battery when the voltage of the at least one battery reaches the voltage value, which is lowered according to the set values. actively lower a voltage value of the at least one battery according to set values in a stepwise manner in response to a connection holding time between the power interface and the external power source elapsing section-wise threshold times after a voltage of the at least one battery reaches the voltage value in a state in which the external power source is connected to the power interface; and control the power management module to block the external power supplied to the at least one battery when the voltage of the at least one battery is above or at the voltage value, wherein at the voltage value, the at least one battery is considered to be fully charged such that the at least one battery is not charged anymore, and wherein the processor is further configured to: when lowering the voltage value of the at least one battery to the set values in the stepwise manner, control the power management module to switch the at least one battery to a discharge state; and control the power management module to release the discharge state of the at least one battery when the voltage of the at least one battery reaches the voltage value, which is lowered according to the set values. when lowering the voltage value of the at least one battery to the set values in the stepwise manner, control the power management module to switch the at least one battery to a discharge state; and control the power management module to release the discharge state of the at least one battery when the voltage of the at least one battery reaches the voltage value, which is lowered according to the set values.