Early Car Battery Failure Detector – 555 Timer

3,522 views

In this tutorial, we are making an Early Car Battery failure circuit. It will give an early indication of the failure of your car battery by activating a buzzer for a few seconds. In this way, you will know beforehand that your battery is now near to failure.

The battery that your car owns is a lead-acid battery which helps to start the engine. This battery lasts for 4-6 years. When it is new it drops only 2 volts during cranking but as the time passes and the battery gets old it starts dropping 5-6 volts due to which the car engine doesn’t start. This circuit will solve this problem by measuring the voltage drop of the battery. It produces an alarm through a buzzer when the battery’s voltage drops to 8V while cranking.

ne555-timer-ic

Hardware Components

The following components are required to make Battery Failure Detector Circuit

S.noComponentValueQuantity
1.Cigarette Lighter Plug1
2.ICNE555 Timer1
3.Zener Diode3.3V1
4.Resistor27K, 8.2K1, 1
5.Variable Resistor10K1
6.Capacitor10nF, 470uF/16V1, 1
7.Piezo buzzer1

NE555 IC Pinout

555 timer ic pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer

Battery Failure Detector Circuit

Car Battery Failure Detector Circuit

Working Explanation

The main component of this circuit is a 555 timer IC which is working in a comparator mode. The input supply is given from a cigarette lighter plug in your car. A variable resistor is used to adjust the frequency of the 555 timer IC. For the alarm, we are using a piezo buzzer.

Circuit Adjustments

After building this circuit there are some adjustments needed to be done while tuning this circuit for the first time. For that, you will need a variable power supply.

  • After completing the circuit do not connect it with the cigarette lighter connection.
  • Set the voltage to 8V in the variable power supply and connect the circuit with it.
  • Adjust the 10K variable resistor until the buzzer produces a sound.
  • Now remove the variable power supply and connect it with the cigarette lighter connection your circuit is ready to start.
  • For accuracy make sure the circuit is fitted in a suitable enclosure.