Abstract: ：With having many advantages, Li-ion battery has become the key research topics for large capacity storage. Lithium ion battery management system must be designed to maintain the battery safety operation and prolong its cycle life. This paper proposes a new hierarchical management strategy for Li-ion battery, which may monitor and manage the cells, battery packs and the energy storage subsystem. At the same time, it discusses the structure and function of each layer and introduces the main function of the Li-ion battery management system, especially the cell data acquisition part, state-of-charge estimation and the balancing part. They are verified by the experiments. The experimental results show that the system can meet the need of the energy storage system, realized the high precision of state-of-charge estimation and the balancing management function of Li-ion battery. It provides a technical solution for managing large capacity lithium ion battery energy storage system and a good application prospect.

Key words: energy storage technology, battery management system, data acquisition, state-of- charge, balancing management