A wireless power receiver for transferring power received from a wireless power transmitter to a battery , the wireless power receiver comprising: a reception coil to receive AC power from the wireless power transmitter ; a rectifying unit to rectify the received AC power into DC power; a switch between the rectifying unit and the battery ; and a control unit , wherein the control unit is configured to measure a first voltage applied to the switch , to determine whether the measured first voltage is equal to or higher than a first threshold voltage, characterized in that the first threshold voltage refers to a minimum voltage required to allow the battery to operate in a charging mode, and in that the control unit is configured to to supply the DC power to the battery such that the battery operates in the charging mode when the measured first voltage is equal or higher than the first threshold voltage, to periodically measure a second voltage applied to the switch while the battery is in the charging mode by the control returning to the measurement of the second voltage if a preset time is elapsed in order to confirm whether the battery is maintained in the charging mode, to determine whether the measured second voltage is equal to or higher than a second threshold voltage, wherein the second threshold voltage refers to a minimum voltage required to allow the battery to be maintained in the charging mode, to supply the DC power to the battery such that the battery maintains in the charging mode when the measured second voltage of the DC power is equal to or higher than the second threshold voltage, and to block a supply of the measured second voltage to the battery when the measured second voltage of the DC power is lower than the second threshold voltage, wherein the second threshold voltage is lower than the first threshold voltage. a reception coil to receive AC power from the wireless power transmitter ; a rectifying unit to rectify the received AC power into DC power; a switch between the rectifying unit and the battery ; and a control unit , wherein the control unit is configured to measure a first voltage applied to the switch , to determine whether the measured first voltage is equal to or higher than a first threshold voltage, characterized in that the first threshold voltage refers to a minimum voltage required to allow the battery to operate in a charging mode, and in that the control unit is configured to to supply the DC power to the battery such that the battery operates in the charging mode when the measured first voltage is equal or higher than the first threshold voltage, to periodically measure a second voltage applied to the switch while the battery is in the charging mode by the control returning to the measurement of the second voltage if a preset time is elapsed in order to confirm whether the battery is maintained in the charging mode, to determine whether the measured second voltage is equal to or higher than a second threshold voltage, wherein the second threshold voltage refers to a minimum voltage required to allow the battery to be maintained in the charging mode, to supply the DC power to the battery such that the battery maintains in the charging mode when the measured second voltage of the DC power is equal to or higher than the second threshold voltage, and to block a supply of the measured second voltage to the battery when the measured second voltage of the DC power is lower than the second threshold voltage, wherein the second threshold voltage is lower than the first threshold voltage. <EOS>