To provide a reasonable charging device that integrates a current controlling circuit for pulse-charging with a constant current as switching control systems including pulse width modulation PWM and pulse frequency modulation PFM, and to provide a battery pack with a charge-controlling function using the device.

A switching converter in a charging circuit operates in accordance with both pulses outputted from the PWM or PFM means and from a pulse-charging on/off controlling means. The PWM or PFM means controls the charging current value so that it becomes a given value. The pulse-charging on/off controlling means keeps the pulse charging turned on until the battery voltage reaches a charge-stopping voltage, turns off the pulse charging when it reaches the charge-stopping voltage, and turns on the pulse charging again when it drops to a charge-resuming voltage.