Patent ID: 7183748

Claim:
An electric charger, comprising: a charging circuit outputting a charging voltage in correspondence with the number of battery cells incorporated in a battery in a supply state of an external power supply; a charging control unit which, upon detection of connection of said battery functioning normally, said battery is charged by turning on a switch unit provided in a connection path extending from the charging circuit to the battery; and a cutoff releasing circuit which, upon detection of connection of said battery in a cutoff state caused by overdischarge, outputs a releasing voltage for releasing the cutoff state set by over-discharge of the battery, wherein the cutoff releasing circuit comprises: a first FET switch connecting a drain to the output of the charging circuit; a second FET switch which has a source connected to the source of the first FET switch and a drain connected to the battery and which is ON/OFF-controlled by the charging control unit, and a switch control circuit which, upon connection of said battery in a cutoff state caused by over-discharging, turns on the first FET switch in accordance with a battery abnormal signal outputted from the battery, thereby applying a charge voltage for releasing the cutoff state to the battery via a parasitic diode of the second FET switch in an OFF state.