This is simpl voltage indicator circuit using leds . This circuit shows how many volt your battery have I had use only 4 LED and 4 zender diod u can make it more sensitive by using More led and zender diod .
When u increase the voltage of battery to 7 volt 1 LED will glow and when battery is of 9 volt 2 LED will glow and on 11 V battery 3 LED and on 13 V 4 LED will glow .
