Arduino Battery Level Voltage Indicator Circuit


The Arduino Battery Level Voltage Indicator is a circuit designed to display the status of a battery using three LEDs – green, yellow, and red. It allows the user to manage and control the batteries efficiently. The circuit uses the analog pin A0 on the Arduino board to measure the voltage of the battery. The analog signal is then converted into digital form by the microcontroller, which then displays the voltage level using the LEDs.

Hardware Required

The following is a list of the components required to build the Arduino Battery Level Voltage Indicator Circuit

Components#Buy From Amazon
Arduino UNO1Buy Link
LED (Green, Yellow, and Red)3Buy Link
Resistors 220Ω3Buy Link
Resistors 1K0Ω1Buy Link
Battery  0 – 5v1Buy Link
Jumper Wires7Buy Link
Breadboard1Buy Link

Circuit Diagram


Working Explanations

The circuit develops in such a way that when the voltage level of the battery is at its maximum, the green LED will light up, and as the voltage level decreases, the yellow and red LEDs will light up. The analog pin A0 is connected to the positive terminal of the battery via a 10k ohm resistor, while the negative terminal of the battery is connected to the ground. The LEDs are connected to the digital pins of the Arduino board via 220-ohm resistors. When the voltage level of the battery is measured, the Arduino will then determine which LED to light up based on the voltage level, which is then displayed to the user.

Having built the circuit, we just have to do the math depending on the voltage of the battery or batteries.
In my case I used two AA batteries in series which theoretically correspond to 3V, so we will write:

  • 3V – 2.8V >Max Voltage, Full Charge 
  • 2.8V – 2.2 <> Average voltage, Average charge
  • 2.2V – 0V < Minimum voltage, low battery

So we will calibrate the Arduino to these values:

  • If 5V corresponds to 1023
  • 3V correspond to 614 .
  • 2.8V corresponds to 573.
  • 2.2V corresponds to 450.

Installing Arduino IDE Software

First, you will require to Download the updated version of Arduino IDE Software and Install it on your PC or laptop. if you Learn How to install the Arduino step-by-step guide then click on how to install Arduino Button given Blow


And that’s all, remember that Arduino does not support voltages higher than 5V so never exceed this voltage in the INPUT at the Pins.

//For more Projects:

int value; //declare the value variable that will store the value given by the analog-to-digital converter
int Red=8; //declare an integer variable where I will connect the red LED
int Yellow=9; //declare an integer variable in which I will connect the yellow LED
int Green=10; // I declare an integer variable in which I will connect the green LED

void setup()
  pinMode(8,OUTPUT); //tell Arduino that pin 8 (DIGITAL IN/OUT) is to be used as OUTPUT
  pinMode(9,OUTPUT); //tell Arduino that pin 9 (DIGITAL IN/OUT) is to be used as OUTPUT
  pinMode(10,OUTPUT); //tell Arduino that pin 10(DIGITAL INPUT/OUTPUT) is to be used as OUTPUT
void loop()
 delay(100); //wait(100 milliseconds);
 value=analogRead(0); //Read the analog value at port A0 and put it in "value"
 if (value>573) //if value greater than 573 then....
   if ((value<573)&&(value >=450)) //if value greater than 450 and value less than 573 then....
   if (value<450) //if value less than 450 then....

 delay(500); //I wait half a second


  1. This circuit can be used to measure the voltage level of any battery, including those used in vehicles.
  2. It can also be used in solar power systems to monitor the voltage level of the battery.
  3. It can be used in portable electronic devices to monitor battery life.
  4. This circuit can be incorporated into battery charging systems to indicate the status of the battery being charged.
  5. This circuit can be used as a low battery indicator in electronic devices.


The Arduino Battery Level Voltage Indicator is a simple yet effective circuit that allows the user to monitor the voltage level of a battery using LEDs. This circuit can be useful in various applications, including monitoring the battery levels of vehicles, solar power systems, portable electronic devices, and battery charging systems.

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