Battery Monitoring System (BMS) Using Arduino UNO

Abstract - A Battery Monitoring System (BMS) is an electronic setup designed to track essential parameters of rechargeable batteries, such as voltage, current, and State-of-Charge (SoC). By preventing overcharging and over-discharging, such systems help extend the lifespan and reliability of batteries. However, commercially available BMoS solutions are often costly and unsuitable for budget-friendly embedded systems. Given the widespread use of Arduino Uno for its affordability, open-source platform, and user-friendly programming environment, this study aims to develop a BMoS using an Arduino Uno microcontroller. The proposed system includes voltage and current sensors, an Arduino Uno board, and a liquid crystal display (LCD) for real-time monitoring. To achieve this, the study set out three primary objectives. First, it was necessary to mathematically establish the relationship between the sensors' input and output values. These mathematical expressions were then validated by observing sensor outputs under varying load conditions — by connecting and disconnecting the load and monitoring the corresponding readings. Following this, a complete BMoS prototype was assembled by integrating the sensors and LCD with the Arduino Uno. The system was tested using an 11.1 V Lithium-ion battery connected to a DC motor as a load. Test results showed that the current sensor read zero when no load was present, confirming no current flow. Additionally, the LCD accurately displayed a battery voltage of 11.1 V when fully charged. This developed BMoS allows users to continuously monitor a battery’s voltage, current, and SoC, ensuring it is neither overcharged nor excessively discharged. The system provides a practical, low-cost solution for managing battery performance in various electronic applications. Ultimately, the prototype demonstrated its effectiveness by offering users a simple, efficient means of supervising battery operation, thereby enhancing system reliability and ease of use. Key Words: Battery Monitoring System, State-of-Charge, liquid crystal display, Arduino Uno, current sensors.