SAE J1634_202104

This SAE Recommended Practice establishes uniform procedures for testing battery electric vehicles (BEVs) which are capable of being operated on public and private roads. The procedure applies only to vehicles using batteries as their sole source of power. It is the intent of this document to provide standard tests which will allow for the determination of energy consumption and range for light-duty vehicles (LDVs) based on the federal emission test procedure (FTP) using the urban dynamometer driving schedule (UDDS) and the highway fuel economy driving schedule (HFEDS) and provide a flexible testing methodology that is capable of accommodating additional test cycles as needed. Additionally, this SAE Recommended Practice provides five-cycle testing guidelines for vehicles performing supplementary testing on the US06, SC03, and cold FTP procedure. Realistic alternatives should be allowed for new technology. Evaluations are based on the total vehicle system’s performance and not on subsystems apart from the vehicle. NOTE: The range and energy consumption values specified in this document are the raw, test-derived values. Additional corrections are typically applied to these quantities when used for regulatory purposes (corporate average fuel economy, vehicle labeling, etc.). Battery electric vehicle (BEV) technology has continued to progress since SAE J1634 was revised to include the multi-cycle test (MCT). BEV driving ranges and capabilities continue to increase along with the addition of many new BEV models in the marketplace, further taxing lab testing. In order to reduce lab test burden, a short multi-cycle test (SMCT) is introduced to allow longer range BEVs to perform a fixed distance test in approximately 50% of the dynamometer time of an MCT test, while achieving comparable range and energy consumption results. This method utilizes an off-board discharge process to determine remaining energy in the battery pack. A short multi-cycle test plus steady state (SMCT+) is also introduced to provide driver flexibility for longer range BEVs to perform testing for range, energy consumption, and five-cycle test data simultaneously without the need for additional off-board discharge equipment. Single-cycle test (SCT), MCT, SMCT, SMCT+, and BEV five-cycle testing (Appendix B) have also been amended to allow thermal conditioning prior to driving, a desired customer feature in today’s BEV marketplace to improve vehicle range.