Battery Status Indicator Using Zener Diode

Battery Status Indicator Zener

Battery Status Indicator Zener

12V Battery Status Indicator

The simple 12V battery status indicator is a circuit that shows the battery state only by flashing LEDs. For example, if out of 10 six LEDs are glowing it means 60 percent of the battery power is left. When the battery is fully charged the circuit LEDs will turn on, and the LEDs will turn off one by one as the battery runs down.


Hardware Components

The following components are required to make a 12V Battery Indicator Circuit Component Value Qty
1 Resistors (220, 180, 150, 100) ohms 1,1,1,1
2 LEDs Red, Yellow, Green 4
3 Zener Diode 8.2V, 9.1V, 10V, 11V 1,1,1,1
4 Battery 12V 1




Working Explanation

In a simple 12 Volt, battery status indicator circuit each LED will close on the different voltage that is also labeled on the upper side of the circuit diagram.  Once the 12 Volt battery is completely charged it will light up to 13 volts such that all the circuit LEDs will glow on this level. So once the battery drops down to 12.6 Volt the LED 4 would go off showing that the battery’s total voltage is 12.6 volt. Similar to where the battery voltage runs down to 11.6 volts as described above on the circuit the LED 3 is disabled and signals that the battery voltage is 11.6 Volt and soon.


Applications and Uses

  • The simple 12V battery status indicator can be used to calculate the car battery level.
  • This circuit helps to calibrate the state of the inverter.


Zener diode is composed of P and N type semiconductor materials, it is made of silicon. They are diodes that keep the voltage applied to their ends constant. Zener diodes do not pass current up to a certain voltage value. This voltage is called the break or zener voltage (Vz). When connected to the circuit in the right direction, it works like a normal diode. When it is connected in the reverse direction, it does not conduct until the breakdown voltage (zener voltage), and when the breakdown voltage is exceeded, it passes current in the form of an avalanche effect and turns on. When the reverse voltage is removed, the zener diode returns to its normal state. Since Zener diodes work in reverse polarity, they are reverse connected to the circuit. The Zener point (breakdown voltage) value is determined by adjusting the amount of additive during the production phase.



Posted by Ali Aslan at Wednesday 24th of May 2023 04:35:52 AM