SAE J1718_200811

This SAE Recommended Practice describes a procedure for measuring gaseous hydrogen emissions from the aqueous battery system of a battery-powered passenger car or light truck. The purpose of this procedure is to determine what concentrations of hydrogen gas an electric vehicle together with its charger will generate while being charged in a residential garage. Gaseous emissions are measured during a sequence of vehicle tests and laboratory tests that simulate normal and abnormal conditions during operational use. The results of this test may be used to determine whether or not forced air ventilation is required when a particular electric vehicle and its associated battery and charging system are used in a residential garage. This Recommended Practice defines a procedure for measuring gaseous hydrogen emissions from the aqueous battery system of a battery-powered passenger car or light truck. The purpose of this procedure is to determine what concentrations of hydrogen gas an electric vehicle together with its charger will generate while being charged in a residential garage. Hydrogen is generated from lead-acid (Pb/A) batteries (usually VRLA) during charge. Today's use of Pb/A is limited to Neighborhood Electric Vehicles or special military vehicles. J1718 is not relevant to the new fleet of general purpose electric or hybrid electric vehicles that are being developed with advanced battery technology, which are sealed battery systems with a different chemistry that does not produce hydrogen on charge. Pb/A doesn't have sufficiently high energy density or specific energy to be competitive with today's advanced battery technologies that will be used in the new vehicles under development. Furthermore, procedures that address hydrogen safety in fuel cell vehicles are addressed elsewhere.