FIELD: electricity.
SUBSTANCE: application in the field of electrical engineering. The system includes a battery power source of electric power-driven tool and an auxiliary power supply source. The battery power source has a battery and a monitoring circuit. The battery has at least one battery cell. The monitoring circuit is actuated by electric power supplied from the battery; the circuit controls state of the battery. The auxiliary power supply source outputs electric power that allows operation of the monitoring circuit. The monitoring circuit is made so that when the circuit is inoperable with electric power supplied by the battery in result of battery voltage decrease the circuit may operate with electric power supplied by the auxiliary power supply source.
EFFECT: improving reliability.
14 cl, 6 dwg
