Even with much more stringent Corporate Average Fuel Economy (CAFE) standards coming, the world will not be dominated exclusively by small vehicles. Full-size pickups and SUVs will still be needed for carrying large families, towing trailers, and when equipped with four-wheel drive, for off-road travel. Businesses and fleets of all sizes also need these types of vehicles for their varying activities.
Recently, Raser Technologies showed how these vehicles could survive by using its Extended Range Electric Vehicle (E-REV) powertrain technology. Raser’s E-REV system has been installed in a Hummer H3, a vehicle some say is the most likely to disappear with the new CAFE standards. According to Raser, its Electric Hummer H3 will get 100 mpg for a typical daily drive of 60 miles.
Raser's E-REV powertrain is a designed for use in full-sized 4WD SUVs and light trucks. They represent nearly half of the vehicles on U.S. roads today and can benefit the most from increased fuel economy and reduced emissions. The Electric H3 was developed with FEV Inc. in association with Hummer and the Plug-in Hybrid Development Consortium.Unlike currently available hybrid pickup trucks and SUVs that are parallel hybrids, the E-REV is a plug-in series hybrid. This means it’s propelled only by an electric motor and not the internal combustion engine, as is the case in a parallel hybrid. A small internal combustion engine is used to drive a generator for keeping batteries charged and extending the vehicle’s range. The engine-generator can also supply the traction motor with electric power when the batteries are discharged. General Motors’ Volt also uses a plug-in series hybrid configuration, but smaller.
The electric H3 is propelled entirely by a 200 kilowatt (278 horsepower) Symetron Enhanced AC induction motor. It’s directly connected to a 4WD transmission and transfer case that shares power between the front and rear axles.Because the electric H3’s combustion engine is only used to recharge the batteries, a much smaller and more efficient combustion engine of 1.0 to 2.0 liters can replace the large V-8 normally used in the H3. The small, high efficiency four-cylinder Ecotec engine is connected to the Raser’s 100kW Symetron electric generator to recharge the batteries only when the vehicle drives beyond its 40 mile battery range. Raser says its electric H3 can travel 360 to 400 miles by generating it own electricity via both the internal combustion driven generator and regenerative braking. The generator has been designed to match the most efficient operating speeds of the combustion engine for optimum fuel economy.
Advanced lithium-ion batteries deliver 700 volts of DC power directly to the 3-phase inverter, eliminating a DC/DC converter. Three liquid cooled battery packs are safely mounted between frame rails. Batteries are normally recharged off the grid using a standard a 110 or 220 volt household outlet.
Are electrically-driven Hummers the answer to our transportation challenges? Obviously not. But it’s important to recognize that larger vehicles will still be around in large numbers and they need to be more fuel efficient. Raser says the electric H3 could get 100 mpg if driven only 60 miles with no gasoline used at all if driven 40 miles or less. Even on a 200 plus mile trip, the electric H3 would get 33 mpg … 7 mpg more than the new strict CAFE standards required for light trucks.