This recommended practice addresses energy storage containers. The document defines technical recommendations on the design, manufacture, electrical equipment installation, inspection, system performance testing, and shipping of such containers. This document applies to electro-chemical energy. TÜV NORD provides independent technical due diligence, technical inspections, and standards-compliant certifications of energy storage systems – including large-scale battery storage and associated system components – to ensure stable grid integration, long-term operational reliability, and a. Factory Acceptance Testing (FAT) is a critical step in the Battery Energy Storage System (BESS) procurement process, ensuring that the system meets technical specifications, safety standards, and performance requirements before shipment.