Lithium-ion battery packs are complex assemblies that include cells, a battery management system (BMS), passive components, an enclosure, and a thermal management system. They power a vast array of applications, from consumer electronics to electric vehicles, and require careful engineering to. Power battery packs are the backbone of modern energy storage solutions, driving innovations in sectors like electric vehicles, renewable energy integration, and industrial backup systems. Volumetric energy. As of this writing, lithium-ion (Li-Ion) cells have been the workhorse of small batter-ies for consumer products (such as cell phones and laptop computers) and are now starting to supplant lead-acid batteries and NiMH cells in large packs for applica-tions such as vehicle traction packs and. This data sheet describes loss prevention recommendations for the design, operation, protection, inspection, maintenance, and testing of stationary lithium-ion battery (LIB) energy storage systems (ESS) greater than 20 kWh.