Charger that charges rechargeable battery arranged in electronic device and charging method for rechargeable battery arranged in electronic device

摘要

A charger for an electronic device that charges a rechargeable battery of the electronic device. The charger includes a detection unit, which detects connection of another electronic device to the electronic device through a communication cable including a power supply line. A charging unit charges the rechargeable battery with power supply voltage from the power supply line. A measurement unit acquires a measurement value indicating a degree of a voltage drop of the power supply voltage occurred when the charging unit performs charging. A control unit instructs a charging current value for charging the rechargeable battery with the charging unit. When the detection unit detects connection of the other electronic device, the control unit monitors the measurement value while instructing the charging unit to increase the charging current value from an initial current value and determines the charging current value based on the monitored measurement value.