IE 11 is not supported. For an optimal experience visit our site on another browser.

Volt plug-in hybrid is 'No. 1 priority,' GM says

GM showed off its progress in developing the highly anticipated Chevrolet Volt and detailed its road map for bringing the rechargeable car to the market by 2010.
/ Source: Reuters

General Motors Corp showed off its progress in developing the highly anticipated Chevrolet Volt and detailed its road map for bringing the rechargeable car to the market by 2010, an ambitious timeline challenged by some rivals.

"We are moving with incredible speed," Frank Weber, GM's vehicle line executive in charge of the Volt, told reporters. "This project is not concept work. This program is not theory. It is reality."

Weber said GM's senior executives remain committed to launching the Volt by November 2010, calling the plug-in hybrid the "No. 1 priority project that we have now within GM."

GM, which is counting on the high-mileage Volt to leapfrog Toyota's market-leading hybrid Prius, on Thursday opened its battery research labs and design studio to dozens of journalists and analysts.

The automaker's unusual open-door policy is part of an effort to show a commitment to the electric car technology many environmental advocates see as the best hope to cut oil use and greenhouse gas emissions. GM also wants to win back consumers it lost because of its reputation as the home of the Hummer.

The Volt is being designed to run 40 miles powered by a 400-pound, T-shaped lithium-ion battery pack that will be cooled by a liquid system to keep it from overheating.

Much lighter battery pack
That battery pack is shorter and only weighs a third as much as the nickel metal-hydride battery featured in GM's now-scrapped EV1 electric car, subject of the 2006 documentary "Who Killed the Electric Car?"

The Volt marks the first attempt to adapt lithium-ion batteries, widely used in electronics, for a car, although Toyota is racing ahead with its own work on the same technology.

In its labs, GM is testing dueling battery packs, one supplied by a subsidiary of Korea's LG Chem  and the other built by a division of German auto parts supplier Continental AG using technology developed by Massachusetts-based A123 Systems.

The goal, GM said, is to ensure that it has a battery that can run at least 150,000 miles, last 10 years and allow drivers to accelerate to 60-miles-per-hour in less than 9 seconds.

Roland Matthe, a manager in GM's battery group, said the competing packs were neck-and-neck in tests meant to simulate driving in conditions ranging from Alaska cold to Arizona heat. "If you look at the data they look very similar," Matthe said.

GM has been quietly testing Volt-like technology in a maroon 2005 Chevrolet Malibu sedan at its Milford, Michigan proving track since last year and will began bolting the new batteries into vehicles for track testing this month.

"We've already learned a lot about how this battery behaves," said Michael Bly, GM's director of hybrid vehicle integration.

Gas-tank issue
Among the challenges GM is still grappling with is how to treat an unusual problem: the risk that gas in the Volt's specially pressurized, low-emission tank goes unused.

A gas engine will kick in to recharge the Volt battery as necessary, but with short trips and frequent recharging at a standard outlet some drivers may seldom need fuel.

GM, which has tweaked its global small-car platform for the Volt, could tune its proprietary drive-train software to kick in and burn off gas if needed to prevent engine damage.

Another problem: the first design GM showed off for the Volt at the 2007 Detroit auto show was too boxy and aggressively styled up front to cut through the wind and boost the vehicle's battery-only range.

After extensive wind-tunnel testing, GM designers rounded the front corners on the Volt and gave it a higher and bigger spoiler. Relatively small aerodynamic improvements have boosted the electric range by more than half a mile, Volt design director Bob Boniface said.

Meanwhile, GM engineers are counting on braking to capture energy that will deliver some 20 percent of the power needed for the Volt's 40-mile battery range. Without any braking — in perfectly traffic-free highway driving — the range would be closer to 32 miles, GM engineers said.