Batteriesystem eines tragbaren elektrischen Geräts

摘要

A battery use system for a battery-driven portable electronic equipment includes a first battery (1) chargeable and serving as a direct power supply source, a second battery (2) parallelly connected to the first battery through a switch (3), a voltage detection circuit (4) for detecting an output voltage from the first battery, a consumption current detection circuit (5) for detecting the state of the consumption current of the portable electronic equipment, and a switch control circuit (6) for controlling open and close of the switch in accordance with an output from the voltage detection circuit and an output from the consumption current detection circuit. The switch is closed to charge the first battery by the second battery when the output voltage from the first battery becomes smaller than a predetermined value, and at the same time, the consumption current is sufficiently small.