Automatic power off circuit and automatic power off device for full charging of storage battery of accumulator car

The invention relates to an automatic power off circuit and an automatic power off device for full charging of a storage battery of an accumulator car. The automatic power off circuit is connected with a charger and a storage battery and comprises a voltage reducing circuit, a three-end voltage-stabilizing circuit, a voltage comparing circuit, a relay controlling circuit and a current detecting circuit; the voltage reducing circuit is used for reducing the direct current of an adapter to 16V; the three-end voltage stabilizing circuit is used for stabilizing the voltage from 16V to 12V and providing a reference power supply; the voltage comparing circuit is used for judging that the circuit is in a charging or floating-charging state; a relay is used for receiving a signal sent by the voltage comparing circuit and switching on or off direct current output of the adapter by virtue of a relay switch; the current detecting circuit is used for detecting the charging state of the circuit. The automatic power off circuit and the automatic power off device for the full charging of the storage battery of the accumulator car can be directly inserted between a charger of the accumulator car and the storage battery to be used, can be used for automatically switching off a direct current power supply of the charger after the storage battery of the accumulator car is fully charged, the service life of the storage battery of the accumulator car is prolonged, and the electric energy is saved, and the cost is low.