Hydrogen emissions from electric vehicle batteries undergoing charging in residential garages. Final report
- Geomet Technologies, Inc., Germantown, MD (United States)
Certain kinds of batteries for electric vehicles emit hydrogen during the battery charging process. In residential garages there is the potential for fire and explosion if the airborne concentration of hydrogen exceeds 4 percent of total volume at any location in the garage. This study was conducted to measure the concentration of hydrogen gas that is associated with the charging of electric vehicle batteries in a naturally vented residential test garage. Vents measuring 0, 1, and 6 ft{sup 2}, which were centrally located in the cover of the test garage, were used. In an initial series of tests, hydrogen was injected into the test garage at controlled rates; in a second series of tests, six actual electric vehicles were charged in the test garage, and hydrogen concentrations and air exchange rates between the garage and the outdoors were measured. The results indicate that under well-sealed (no vent) conditions, the lower explosive limit (LEL) can be exceeded by hydrogen emissions of a few hundred liters/hr. With a 1 ft{sup 2} vent, nearly 1000 l/hr would be required to exceed the LEL, and with the 6 ft{sup 2} vent emissions of approximately 5000 l/hr would be required to exceed the LEL. Additional tests in which the 1 ft{sup 2} vent was split between the top and bottom of the garage cover indicated that the split vent was more efficient in ventilating the test garage. A calculation was made of the minimum required ventilation to keep the hydrogen concentration below certain percentages of LEL. The minimum ventilation rate is directly related to hydrogen emission rate. Ventilation of enclosed EV charging spaces will have to be mechanically driven, given the variability of natural ventilation; even with large vent areas, natural ventilation has a probability of occasionally being inadequate to meet minimum ventilation needs.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); GEOMET Technologies, Inc., Germantown, MD (United States); Baltimore Gas and Electric Co., MD (United States); Southern California Edison Co., Rosemead, CA (United States); Edison Electric Inst., Washington, DC (United States); Allegheny Power Co., Greensburg, PA (United States); Salt River Project, Tempe, AZ (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 10160931
- Report Number(s):
- EPRI-TR-103421; ON: UN94013975; TRN: 94:006557
- Resource Relation:
- Other Information: PBD: Dec 1993
- Country of Publication:
- United States
- Language:
- English
Similar Records
Pollutant Exposures from Natural Gas Cooking Burners: A Simulation-Based Assessment for Southern California
Hazard evaluation and technical assistance Report No. TA76-111, U. S. Secret Service vehicle garage, Washington, DC