This document describes a test procedure for rating peak power of the Rechargeable Energy Storage System (RESS) used in a combustion engine Hybrid Electric Vehicle (HEV). Other types of vehicles with non fossil fuel primary engines, such as fuel cells, are not intended to use this test procedure.

The purpose of this document is to provide a test procedure to determine RESS peak power so that a vehicle's ratio of RESS peak power rating to the sum of the Internal Combustion Engine power rating and the RESS peak power rating can be established. Because of the vehicle-specific nature of the RESS control and environment, this test is designed to calculate the RESS peak power for a specific vehicle. As a result, the same RESS used in a different vehicle must be retested to determine its peak power rating in the new HEV environment.