A charge circuit includes a current limiting circuit configured to limit a current input from an input terminal; a first transistor connected between an output terminal of the current limiting circuit and a secondary battery; a charge control circuit configured to turn the first transistor on and off to start and stop supply of a charge current to the secondary battery; a second transistor configured to output a current proportional to the charge current flowing through the first transistor; and a charge timer configured to generate clock pulses according to the current output from the second transistor. The charge control circuit is configured to turn off the first transistor to stop the supply of the charge current to the secondary battery when the number of the clock pulses reaches a predetermined number.