Fast-charging device for rechargeable batteries

摘要

A battery charging device for providing a fast charging a rechargeable battery and controlling the charging process to prevent overcharging. The battery charging device detects a decrease in the voltage of the rechargeable battery as it is being charged and approaches a full charge, and modulates the switching of a switching power supply supplying current to the rechargeable battery in response thereto. The battery charging device has a first resistor in series with the rechargeable battery which is to be charged, a power supply which charges the rechargeable battery, a charging control unit which detects a decrease in the voltage across the rechargeable battery using capacitors and which outputs battery condition signals and battery error signals in response thereto, and a power supply control unit which accepts a mode change signal and a battery error signal from the charging control unit and outputs a control signals for controlling the power supply.