Smart Charger Monitoring System using Arduino

Mobile devices rely on limited-capacity lithium-ion batteries, and improper charging reduces their useful lifespan.Overcharging a fully charged battery (beyond safe thresholds) accelerates capacity loss and even poses safety risks.In this work, we present an Arduino-based controller that allows the user to set a desired charging duration afterwhich the system automatically cuts off the power supply. The design employs an Arduino Uno microcontroller, arotary encoder for user input, an LCD display for feedback, and a 5 V relay to switch the charger circuit. TheArduino program counts down the preset time and then deactivates the relay, interrupting charging. In tests, thedevice reliably disabled the charger at the end of the timer. As a result, unnecessary topping of the battery iseliminated, which can help extend battery life by avoiding continual charging at full voltage. The system also storestime presets in EEPROM so the user’s settings persist between uses. This hardware solution is low-cost and practicalfor preventing overcharging under typical smartphone usage scenarios.