A battery contains lithium cells arranged in series and parallel to form modules, which stack into racks. These racks are the building blocks to creating a large, high-power BESS. BESS cabinets are widely used in: AZE Systems'. . A PCS is the critical device that allows a battery system to convert DC stored energy into AC transmissible energy. The PCS also controls the charging and discharging process of the battery and allows for the large-scale utilization of renewable energy sources, energy storage, and microgrids.