It is far more than just batteries in a box; it is a sophisticated, pre-engineered system that includes battery modules, a Battery Management System (BMS), a Power Conversion System (PCS), an Energy Management System (EMS), and crucial thermal management and fire safety equipment. What are containerized BESS? Containerized Battery Energy Storage Systems (BESS) are essentially large batteries housed within storage containers. These systems are designed to store energy from renewable sources or the grid and release it when required. " – Renewable Plant Manager, Germany 1. Grid Support. Containerised battery storage (CBS) encapsulates battery systems within a shipping container-like structure, offering a modular, mobile and scalable approach to energy storage.