Real-Time Performance Evaluation of an MPPT-Based EV Charging System Incorporating LiFePO₄ Battery Backup

Abstract

This paper presents the design, development, and experimental validation of a real-time solar tracking system integrated with a Maximum Power Point Tracking (MPPT) controller, and a Lithium Iron Phosphate (LiFePO₄) battery storage unit. The proposed system is designed to improve photovoltaic (PV) energy harvesting by continuously optimizing the panel orientation while simultaneously acquiring and monitoring critical electrical and environmental parameters in real time. An MPPT charge controller is incorporated to extract the maximum available power from the solar module under varying irradiance conditions, thereby improving overall energy conversion efficiency. The generated energy is stored in a high-performance LiFePO₄ battery, selected for its high energy density, thermal stability, and extended cycle life. Solar panel positioning is achieved using a bipolar stepper motor driver controlled by a PIC-based embedded controller, while a Real-Time Clock (RTC) ensures accurate daylight-based tracking. In addition, load current is measured through a potential-divider-based sensing circuit, and a temperature-compensated operational amplifier (OP-AMP) filter is employed to improve signal quality and measurement reliability. the proposed system offers a reliable and scalable solution for smart-grid, standalone, and distributed solar energy applications.