diagram ingram

This is the circuit diagram of a 3 LED bar graph type battery
monitor circuit that is ideal for monitoring the voltage level of an
automobile battery.When battery voltage is 11.5V or less transistor Q1
will be On and the LED D1 will be glowing.When battery voltage is
between 11.5 and 13.5V, the transistor Q2 will be On and the LED D2 will
be glowing.When battery voltage is above 13.5V the transistor Q3 will
be On and the LED D7 will be glowing.

Circuit diagram with Parts list.

Assemble the circuit on a general purpose PCB.The battery to be
monitored can be connected between the terminals namely A and B.It is
always better to use LEDs of different colour.