The energy storage device holds a pivotal position in renewable energy systems, facilitating the efficient accumulation and subsequent deployment of energy. However, the inconsistency of lithium-ion batteries has been a key factor limiting their performance and lifespan. This paper examines the inconsistencies of Li-ion batteries and discusses the application of various equalization techniques to improve overall performance and extend battery life. It also compares and analyzes the advantages and disadvantages of different equalization techniques, demonstrating their application in lithium battery packs through simulation. This paper provides important theoretical guidance for enhancing the overall performance of energy storage devices and prolonging battery life.