Charging circuit with function of avoiding battery pulling down voltage output from charging device and charging method thereof

A charging circuit connecting a charging device with a battery, the charging circuit comprising:

• a main control microchip including a power-on pin;
• an enable circuit;
• a charging integrated circuit comprising a power input pin, a battery charging pin, and a current limit pin;
• and
• a current control circuit comprising a transistor, a first current limiting resistor, and a second current limiting resistor;
• wherein the power-on pin is directly and electronically connected to the charging device;
• the enable circuit is connected to the main control microchip and capable of enabling or disabling the charging integrated circuit;
• the power input pin is connected to the charging device, the battery charging pin is connected to the battery, and the charging integrated circuit is capable of limiting charging current output from the battery charging pin according to current through the current limit pin;
• a base of the transistor is connected to the main control microchip, and an emitter of the transistor is connected to ground;
• the first current limiting resistor is connected between the current limit pin and ground, and the second current limiting resistor is connected between the current limit pin and a collector of the transistor;
• the main control microchip is operable to output control signals to enable or disable the transistor to adjust current through the current limit pin.