In response to the planned increased availability of Li-ion based electrically propelled vehicles, NHTSA has initiated a safety research program. This programs’ plan will assess the safety risks associable to Li-ion based rechargeable energy storage systems (RESS) during all operating conditions. NHTSA’s plan is to analyze failure modes through a failure modes and effects analysis (FMEA), develop repeatable test procedures and safety metrics to measure effect of the failure modes, and analyze the performance characteristics of an effective RESS control system