Design and Testing of a Smart Battery Management System for Swappable LiFePO4 for E-Rickshaws

The global automotive industry is rapidly transitioning to electric vehicles (EVs), with e-rickshaws playing a crucial role in developing nations due to their affordability and environmental benefits. The shift from traditional lead-acid batteries (LABs) to Lithium Iron Phosphate (LiFePO₄) batteries is vital, but requires a sophisticated Battery Management System (BMS) for optimal performance and safety. One of the major challenges faced by e-rickshaws is ensuring efficient, safe, and reliable battery performance over extended periods. This research focused on designing and testing a smart BMS specifically for swappable LiFePO₄ batteries in e-rickshaws. Objectives included optimizing the BMS for e-rickshaw operations, implementing real-time monitoring and control, integrating IoT features for remote diagnostics, and testing its performance. The methodology involved developing both hardware (LiFePO₄ cells, microcontroller, sensors) and software components (simulation tools like MPS and Victron Connect, advanced algorithms for SoC and SoH). The system's architecture emphasized real-time monitoring and control, ensuring a holistic and interconnected design. The designed smart BMS demonstrated robust performance, evidenced by a tightly controlled output voltage ripple, oscillating minimally between approximately-3mV and +3mV, indicative of superior power regulation. Efficiency analysis revealed a peak of over 97% at a 0.5A output current, which gradually decreased to approximately 93.5% at 3A, showcasing effective energy conversion and minimal power loss (increasing from near 0W to 1W at 3A) across the operational range. Real-time monitoring via the BMV-700 system further validated the accuracy and reliability of the monitoring and control algorithms, consistently showing stable operational parameters, including a constant power output of -191W, a steady current draw of -7.5A, a stable State of Charge at 85%, and a constant battery voltage of 25.46V. This study's successful design and testing of a smart BMS for swappable LiFePO₄ batteries in e-rickshaws significantly advances operational efficiency, enhances safety, and accelerates the adoption of sustainable urban mobility solutions in developing regions.