Powertrain of the Chevy Volt concept. The production battery pack will be arranged in a “T” shape, running behind the seating area as well as down the center of the vehicle. Click to enlarge.

Present were: Frank Weber, Global Vehicle Chief Engineer for the E-Flex Systems; Tony Posawatz, Vehicle Line Director, E-Flex Systems and Chevy Volt; Denise Gray, Director of Hybrid Energy Storage Systems and Strategy; and Al Weverstad, Executive Director, Environment and Safety Policy. Weber, who hails from Germany, said that his presence is evidence of the company’s determination to make E-Flex a “global strategy.”

Events such as these are part of the company’s new transparency, along with GM’s Fastlane blog and teleconferences, to keep the EV and PHEV community informed about progress on the Volt as well as the larger E- Flex project. Such efforts also dovetail with the company’s effort to position Chevy as a multi-fuel leader and GM’s greenest brand, and to make amends for the negative publicity that surrounded the demise of GM’s EV1 electric car.

Announced in January, the Volt is the first of a planned series of vehicles to be built and sold worldwide around a common core of components called “E-Flex.” The components can be configured to create an electric vehicle or a plug-in series hybrid fueled by gasoline, diesels, biofuels, or hydrogen.

In the case of the Volt, the configuration will be a gasoline or E85-fueled plug-in hybrid with an all-electric range (AER) of 40 miles and an “aggressive” target production date, according to Bob Lutz, of November 2010. General Motors is promoting the use of the EREV acronym to distinguish E-Flex variants from competing plug-in hybrids.

Making Lithium-Ion Work. The 16 kWh battery packs required to propel the Volt are the source of much speculation, and several details emerged about the packs:

• The original Request For Proposals for the Volt battery pack went out to 22 companies. 13 returned technical proposals, and two partnerships (Compact Power/LG Chem and Continental/A123Systems) were chosen. (Earlier post.)

• A123Systems also won a second development contract for cells. GM took delivery of its first test pack at the end of October from Compact Power/LG Chem, and the automaker expects its first pack from A123 and Continental by year’s end. (Earlier post.)

Both packs are designed to be bench-tested, rather than installed in a development vehicle. They will be evaluated with a cycler, a machine that can charge and discharge the pack to simulate specific driving cycles. The pack can then be tested in a variety of scenarios, such as one depleted cell, one shorted cell, or excessive resistance. The pack cells are prismatic (rectangular in shape) as opposed to the cylindrical shape that is prevalent among today’s Li-Ion cells. The production pack will be arranged in a "T" shape, running behind the seating area as well as down the center of the vehicle, much like the pack configuration used in GM’s EV1.

The Volt’s battery pack will be liquid-cooled; company officials declined to identify the coolant, although “it won’t be Flourine”, which GM has used to cool hybrid electronics in the past. What are the barriers to success with lithium-ion? “Basically, it comes down to two issues," explained Denise Gray, GM’s Director of Hybrid Energy Storage Systems, “thermal management and cost.”

Al Weverstad quoted Bob Lutz, chairman of GM North America, who remarked in August that “breakthrough battery technology will drive future automotive propulsion, and the company that aligns with the best strategic partners will win.” Weverstad also said he is confident the battery technology can handle 40 miles of all-electric range; remaining issues involve durability and cost. The battery pack specification requires no more than 20% battery degradation after 10 years.

Company officials said that if one company lands the Volt battery order for 60,000 to 100,000 vehicles—at 16 kilowatt-hours and 300 cells per pack&mash;that company will immediately become the world’s largest lithium battery manufacturer.

Moving Toward Production. Frank Weber described the E-Flex as “GM’s highest priority project.” He noted that five years ago, “no one expected that batteries would improve so much.” He emphasized that the Volt was destined for mass production, GM style: “not for a few hundred test vehicles, not for a niche market.”

As mass production nears, costs for many components that have been designed for the Volt are expected to fall sharply, by as much as 50%. The company hopes to sell the first-generation Volt for around US$30,000, putting it within the high range of compact cars.

The design will include the “building blocks” for future versions to incorporate an electric meter in vehicle-to-grid (V2G) applications.

Comparing the fuel costs between old and new methods of propulsion, GM estimated that driving costs in EV mode would be 2 cents per mile&mash;or 1 cent per mile if charged off-peak—compared to about 12 cents per mile per gallon of gasoline for a typical car today.

The company settled on a 40-mile all-electric range because it would cover daily driving of 78% of Americans, according to US Department of Transportation figures. Had GM picked 30 miles, it would have covered 68%; 20 miles would have covered 51%. When asked why GM didn’t start with 30, Weber smiled and responded “it’s easier to go from 40 to 30 than from 30 to 40.”

In light of the European Union’s proposed limitations of 120-130 grams/kilometer of CO₂, the Chevy Volt (or the Opel Flextreme) will count as a 40 gm/km of CO₂ vehicle, using current EU testing procedures. GM will publish a SAE technical paper on this subject early next year.

Project leaders reiterated their keen interest in developing methods to educate the public and manage expectations, to determine the best ways to present the total cost of ownership of PHEVs, and in the need to engage with a rapidly evolving public policy and economic landscape, including co-operation with utilities to explore such issues as secondary roles for vehicle battery packs.

Weverstad emphasized that the company still does not view PHEVs as the end-point, but rather expects to develop fuel cell cars because those vehicles offer “emission-free driving, long range, and a short refueling time”. As with Toyota at the LA Auto Show, both companies clearly still have some executives insisting on maintaining that dual emphasis.

Not all is rosy at GM: the striking styling of the Volt concept car has officially been nixed due to a poor coefficient of drag. At a briefing for bloggers, GM head Bob Lutz quipped to the media that “we probably would’ve gotten better drag coefficient if we put it in the wind tunnel backwards.”

“Last year, we were 90% committed to the Volt,” said Lutz. “Now, we’re totally committed.”