This is an article from the Popular Mechanic.
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scaling up its powertrain concept to larger vehicles is tantalizing. So when
Raser Technologies unveiled its 100-mpg-equivalent Hummer H3 at the 2009 SAE
World Congress, it grabbed headlines. But we wanted to get a taste of what
it's like to slide behind the wheel of Raser's plug-in prototype on real
roads. We got the chance two days ago as the Raser crew stopped briefly in
Southern California before heading up to Sacramento for a drive event with
Governor Schwarzenegger. So is the 100-mpg Hummer ready for prime time?
Let's find out. -Ben Stewart
The Specs
The Raser Technologies Hummer is a combined effort between the company,
integration partner FEV and General Motors. The powertrain is similar to
that of the Volt in that this is an electric vehicle that uses an internal
combustion engine to charge the batteries when the original plug-in charge
of the packs is depleted. And unlike a conventional hybrid, that engine does
not power the vehicle. The Raser Technologies-developed electric traction
motor develops 200 kW peak and is mated to the front of the stock GM 4L60E
four-speed transmission, which sends torque through the stock transfer case
and to both the front and rear axles. The powertrain provides 40 miles of
electric range before the gas engine kicks in to charge the packs for around
400 miles of total range.
Under the hood is a turbocharged GM Ecotec four-cylinder engine, similar to
the unit used in the Pontiac Solstice GXP. That engine turns a generator
that helps charge the three battery packs. Two of the lithium-ion battery
packs are mounted on either side of the undercarriage and one is located at
the rear of the chassis. In total, the packs provide 41 kWh. The batteries
on this vehicle are lithium-ion "super-polymer" units from Canadian supplier
Electrovaya. But Raser is also working with Enerdel and Korean supplier SK.
The packs are liquid-cooled, as is the electric motor. Raser PHEV Program
Manager and former Honda Engineer KC Jones says, "Lithium battery suppliers
come to the automotive market fresh-it isn't the same as consumer
electronics or power tools-it's new ground for them. So in addition to
having great chemistry, they need to develop a durable package that can
withstand, say, rough road driving for up to 10 years."
This truck has an AC converter mounted in the cargo hold to provide export
power for situations as diverse as a camping trip or emergency power outage.
Once in production that generator will be integrated underhood and will
provide a valuable tool for fleet sales to utility companies who rely on
mobile power sources. Though Raser used the H3 to prototype their
range-extended powertrain, the system is scalable to full-size pickups like
the Ford F-150 or Chevy Silverado.
The Drive
Twist the key and, as with most EVs, you don't hear much. The gauge cluster
lights up and shows a few trouble-code warning lights-as you might expect in
a prototype. On the dash above the stereo and HVAC controls is a display
that shows how the energy is flowing to the various systems on the truck. In
production models, Raser says this display would be integrated into the
stock navigation screen.
Since the electric drive is routed though the conventional four-speed
automatic, you just pull the gearshift back to "D" and squeeze the throttle
as you would in any car. But the sounds are not entirely silent. Since there
is no longer a torque converter, Raser must provide adequate line pressure
to the transmission, so you hear the muted buzz of the pump until the truck
moves forward. Raser uses a conventional hydraulic steering pump too, but
that can only be heard from outside the vehicle.
Unlike many electric vehicles, this Hummer doesn't leap off the line. The H3
is a development vehicle, and the electric motor provides around 300 lb.-ft.
of torque at zero rpm, so to keep parts from breaking, the thrust from a
full-throttle launch is soft. According to Jones, as the testing evolves the
company will incorporate a steeper power ramp-up. Once underway, the ride is
essentially silent, with the exception of a mild hum from the all-terrain
tires. Our drive was short, just 15-minutes long. That distance wasn't
sufficient to deplete the batteries enough to have the Ecotec begin charging
for the packs. But that part of the puzzle is still very much in
development. In theory, the four-cylinder is only used as a generator and
would run at a constant rpm. But Jones says that may not be ideal for every
situation. If a customer were sitting at a traffic light and the truck's
engine was running along at, say, 3000 rpm, it might seem quite odd to the
driver-and other motorists too. So Jones says the ultimate solution would be
to have the system slow the engine to idle in certain situations so that it
mimics conventional vehicles.
A keen eye will notice that the Raser H3 sits a bit lower than a regular
production Hummer. That's because its new powertrain adds approximately 1000
pounds to the 4700-pound truck. On the road, even at 30 to 40 mph, you can
certainly feel that extra weight. We'd guess it would seem less noticeable
on a full-size pickup. Jones mentioned that the powertrain probably has more
battery power than it needs right now. He thinks the final production system
may only require 26 to 28 kWh. If true, the system's total weight would drop
by a few hundred pounds.
The Bottom Line
The Raser H3 is still very much a prototype. But the company expects to have
the first two vehicles in "alpha" testing with San Francisco-based Pacific
Gas and Electric later this year. The company has 12,000 "soft" orders from
fleet customers. So in 2010, the company will begin "beta" testing with some
of them using Hummer H3s, Hummer H3Ts, Chevy Silverados and Ford F-150s.
They expect to begin high-volume production in 2011.
The cost of the system, Raser says will be approximately 25 percent of the
total cost of the fleet vehicle. And the company is working with the OEMs so
that when the vehicles are up-fitted with the powertrain, the conversion
maintains as much of the factory warranty as possible. We hope to test one
of these trucks as Raser moves closer to production.
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