Low Battery Indicator using 555 Timer

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In this circuit, we are making a 555 low battery indicator for 6V batteries. As we all know rechargeable batteries are expensive and they have a tendency of getting deep discharged. Every time they get completely discharged; they lose their capacity which results in short battery life. It can cost you a lot, but with this circuit, you can solve this problem. This circuit will indicate when the battery is low and needs charging by activating an LED. The main component of the circuit is a 555 IC. The 555 timer IC is commonly used in a lot of circuits.

Hardware Components

The following components are required to make Low Battery Indicator Circuit

S.no	Component	Value	Quantity
1.	Battery	6V	1
2.	IC	NE555 Timer	1
3.	Resistor	27KΩ, 8.2KΩ, 200Ω, 10K Var	1, 1, 1, 1
4.	Ceramic Capacitor	10nF	1
5.	LED	–	1
6.	Zener diode	3.3V	1

NE555 IC Pinout

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

Low Battery Indicator Circuit

Working Explanation

This circuit is built around the 555 timer IC that is wired as a comparator. The frequency of the 555 timer is set by a combination of resistor and capacitor at its input pin. To adjust the voltage level at which you want the indication we have used a 10K ohms variable resistor.

After building this circuit you will have to make some adjustments for the first time before using it. For that, you will need an adjustable power supply and set its output voltage to 6V. Remove the battery from the circuit and replace it with the adjustable power supply. Start adjusting the 10K variable resistor slightly. Keep adjusting it until the LED goes off. After this, your adjustments will be done, remove the power supply and put the fully charged 6V battery back in its place. Now you can monitor this circuit, when the voltage of the battery will fall below 6V the LED will be activated.