Design and Implementation of a Simple Wireless Battery Monitoring System for Photovoltaic Applications

This document showcases the work planned and undertaken in designing and implementing a simple wireless battery monitoring system for photovoltaic (PV) applications. The proposed solution is a wireless monitoring system that consists of three main layers: data acquisition, data processing, and data display. The data acquisition layer consists of two sensors (INA219 and MAX6675) which measure the discharge current, voltage, and temperature of the battery. The processing layer consists of two Heltec ESP32 microcontrollers which utilise LoRa and Wi-Fi wireless communication technology to transfer data from sensors to the ThingSpeak cloud. In the processing layer, the battery state of charge (SOC) is calculated using the coulomb counting method. The data display layer consists of an organic light-emitting diode (OLED) screen and ThingSpeak cloud solution which allows for real-time monitoring of the battery parameters in any location with an internet connection. The result was a fully working prototype capable of accurately monitoring the voltage, current, and temperature readings of a battery.