Monitor your Car battery or Inverter battery with this simple circuit. It always follows the terminal voltage of the battery and gives corresponding LED indications. A 12 volt Lead-Acid battery attains 13.85 volts in full charged condition and Inverter Tubular battery 14.85 volts. So it is necessary to have an idea about the charge status of the battery. If the battery discharges below 10 volts, it needs immediate charging to prevent the deep discharge. The circuit gives three LED indications. If the terminal voltage of the battery rises above 13.5 volts, Red LED lights. If the voltage drops below 10 volts, Green LED lights. If the voltage is normal around 12 volts, both the LEDs remain off.