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Electric Vehicles
An electric vehicle (EV) is driven by an electric motor with power supplied by on-board batteries. In the 1990s California environmental policy and regulation encouraged the sale and lease of electric cars and supported recharge facilities. In early 2006, a small proportion of those vehicles remained on the road [1]. There have also been experimental programs for electric vehicles in the New York City area [2]. Manufacturers have R&D programs for future production of EVs, but current production favors hybrid vehicles combining gasoline and electric drive.
Electric vehicles have been built with AC and DC motors, operating in the range of 300 volts. Power is supplied most commonly by either nickel-metal-hydride or lead-acid batteries. Packs of individual batteries (often 12 volts each) are generally located forward of the rear axle in closed, vented compartments. The batteries in series supply the high voltages required by the motors.
Vehicles sold in the United States operating with more than 48 volts are required to comply with Society of Automotive Engineering "Recommended Practice for Electric and Hybrid Electric Vehicle Battery Systems Crash Integrity Testing" (SAE J1766), and US Federal Motor Vehicle Safety Standard 305, “Electric Powered Vehicles, Electrolyte Spillage and Electrical Shock Protection.” These requirements limit the amount of electrolyte spillage and electrical insulation degradation in frontal (FMVSS 208), side (FMVSS 214) and rear (FMVSS 301) crash tests. Even if a vehicle complies with these standards, impacts of differing configurations or energy levels may still compromise the high-voltage systems resulting in fire or electric shock.
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