Although there were some previous concerns over the
feasibility of General Motors' Chevrolet Volt electric car, it appears the
company is ready to charge ahead with production. GM is making the necessary
steps to ensure that the Volt makes use of best available battery technology to
achieve its project goals -- something that Toyota is having a few problems with
The company announced yesterday that 13 companies sent in proposals
regarding the advanced lithium-ion batteries used to power the Volt. When the
dust settled, two companies were selected. The first contract was awarded to
Compact Power (a subsidiary of LG Chem) while the second contract went to
Continental Automotive Systems.
"The signing of these battery development contracts is
an important next step on the path to bring the Volt closer to reality,"
said GM Chairman and CEO, Rick Wagoner. "Given the huge potential that the
Volt and its E-Flex system offers to lower oil consumption, lower oil imports,
and reduce carbon emissions, this is a top priority program for GM."
The Chevrolet Volt uses a tiny, turbocharged 1.0 liter
internal combustion engine (ICE) to charge its onboard lithium-ion battery
pack. The ICE is not, however, used to provide propulsion for the vehicle --
that is left to the electric motors. GM says that the Volt can travel 40 miles
on battery power alone before the ICE needs to kick in to charge the batteries
back up again.
A second version of the Volt is also in the works. GM
unveiled a fuel-cell
variant of the Volt built on GM's E-Flex architecture in April. This Volt
comes equipped with an 8kWh lithium-ion battery pack, three electric motors and
a 4kg hydrogen fuel tank. The vehicle is capable of traveling over 320 miles
with a fully topped off battery, can zip from 0 to 60 in around 8.2 seconds and
has a top speed of 120 MPH.
quote: The only thing they could do to cut costs of the battery packs down is come up with one or a few standard battery packs that all the car manufacturers use.
quote: Other key proportional highlights include a dash-to-axle length that positions the driver far rearward of the front wheels; large 21-inch by 7.5-inch wheels; short front and rear overhangs and departure angles that deliver a sense of taut, compact energy.
quote: momentum that is lost when decelerating or turning
quote: If this were true, a car, once moving, could turn in a circle forever without the engine running.
quote: > "Assuming no other sources of friction."But that's just the point.
quote: Here's a link I found you to an automobile forum, which has several people discussing their real-world loss in MPG from going to larger tires.
quote: A larger wheel provides a large contact patch
quote: Lets assume a wheel mass of 12kg, uniformly distributed around the inner edge of tire itself (outer edge of the rim).
quote: This gives is a moment of inertia I of 3kg(m^2) per wheel
quote: A car at 70mph has its wheels rotating at around 43. rads/sec.
quote: Kinetic Energy of all four wheels is therefore 1/2I..^2 = 1.12E5 Joules.
quote: Comparing that to the KE of the entire vehicle, lets assume a mass of 1800 kg (at the same speed of course).
quote: 1/2mv^2 gives us a KE of 1.054E6 Joules
quote: roughly 10% of the KE of our moving vehicle is tied up in the wheels itself.
quote: You misunderstood my remarks. The "other sources of friction" in this case are not a static quantity. Some are quite heavily impacted by the mass of the wheels. Larger wheels increase those sources, and make the vehicle less efficient.
quote: All they do is shift pollution from air to land. So instead of smog we get ecological wastelands from the toxic chemicals that these batteries contain from when they're thrown out.