Design and Development of a 2.5 kWh Lithium Battery for High-Capacity Energy Storage Solution in Modern Applications

Abstract

Frequent power outages and an unstable electricity supply continue to affect residential buildings, workshops, and small businesses, especially in developing economies.Conventional backup systems based on lead-acid batteries are often limited by low energy density, poor cycle life, excessive maintenance, and unstable voltage response under heavy loads.Although lithium-based alternatives have emerged as promising substitutes, many low-cost systems still suffer from poor thermal management, weak battery management integration, inaccurate state-of-charge monitoring, and rapid performance degradation during repeated charge-discharge cycles.This study presents the design, fabrication, and experimental validation of a 24 V, 2.5 kWh lithium iron phosphate (LiFePO 4 ) battery energy storage system integrated with an intelligent monitoring and protection architecture for modern backup power applications.The proposed system employed an 8S1P configuration using 100 Ah LiFePO 4 cells, a smart battery management system (BMS), a 30 A intelligent charger, and an Arduino-based real-time display interface for voltage and current monitoring.Experimental results showed that the battery absorbed approximately 23.5 A at nearly 25% state of charge, indicating excellent charge acceptance and stable regulation.During discharge testing, the system delivered 2.56 kWh while maintaining a gradual voltage reduction from 29.2 V to 23.5 V, demonstrating improved energy retention and output stability.The developed system provides a reliable, safe, and scalable alternative to conventional backup storage technologies.Its practical value includes improved household energy reliability, reduced maintenance requirements, enhanced operational lifespan, and suitability for renewable energy integration in homes, offices, and microgrid applications.