IEC 62973-5:2023 applies to lithium-ion batteries for auxiliary power supply systems used on rolling stock. This document specifies the requirements of the characteristics and tests for the lithium-ion cells, and supplements IEC 62973-1 which is applied to any rolling stock types (e.g. light rail vehicles, tramways, streetcars, metros, commuter trains, regional trains, high speed trains, locomotives, etc.). This document specifies the requirements of the interface between battery system including BMS and the converter. This document is used in conjunction with generic IEC 62619 (safety requirements) and IEC 62620 (performance requirements) of lithium-ion cells and batteries used in industrial applications. This document specifies the requirements for railway rolling stock applications.