The proposed system utilizes a voltage sensor module to continuously measure the battery pack voltage, while adjustable potentiometers are used to set reference voltage and current limits. The Arduino UNO processes the sensor data and calculates the battery’s State of Charge based on predefined voltage thresholds. A regulated power supply ensures stable operation of the control circuitry. The system incorporates a relay module to control the connection between the battery pack and DC motors, enabling automatic cut-off during overcharging, deep discharge, or fault conditions.

To enhance user interaction and system awareness, an LCD display is integrated to show real-time voltage levels and estimated SoC percentage. Additionally, LED indicators and a buzzer provide visual and audible alerts when abnormal conditions occur.

This Arduino-based BMS offers a low-cost and scalable solution suitable for small-scale battery-powered applications such as robotics, electric vehicles (prototype level), and backup power systems. The implementation demonstrates how embedded systems can effectively manage battery performance, improve lifespan, and enhance operational safety through real-time monitoring and intelligent control.

Main Objectives:

  To monitor the battery voltage continuously using Arduino UNO.

  To estimate and display the State of Charge (SoC) of the battery.

  To protect the battery from overcharging and deep discharge.

  To automatically disconnect the load using a relay during unsafe conditions.

  To display battery voltage and SoC on an LCD screen.

  To provide warning alerts using LED indicators and a buzzer.

  To improve battery life and ensure safe battery operation.

Components used:

• Regulated power supply.
• 12V Battery pack.
• Relay.
• LCD display.
• Buzzer.
• TWO POTs.
• Voltage sensor.
• DC motor.

Software’s used in the project:

1. Embedded C language.
2. Arduino IDE for dumping the code into the Microcontroller.
3. Express SCH for Circuit design.

Block Diagram:

video: