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Chevy Volt plowing through water trough to test water-tightness of the vehicle and especially its battery pack.
Pre-production Chevy Volt plows through water trough to test water-tightness of the vehicle and especially its battery pack. This is just one of many grueling tests the car will go through as its nears the start of production in the third quarter of 2010.

Chevy Volt Progress Report: 12 Months and Ticking

Exclusive MP3 audio from 17 Nov 2009 media technical briefing on Chevrolet Volt program

By EV World

As part of its ongoing commitment to keep the public informed of developments in its extended-range electric Volt program, General Motors today hosted a media technical briefing hosted by Andrew Farah, Volt chief engineer, and Bill Wallace, Voltec battery engineering group manager.

The call opened with Farah noting the Volt is now just 12 months from its launch date. He then explained that in order to have a great electric car, you need a great battery and a great cell; and GM is confident they have all three, though as is discussed in the accompanying MP3 audio segments, the company is still learning and adjusting to this new paradigm. Besides hitting milestones like surpassing a quarter million miles on the pre-production Volt fleet of some 80 vehicles, the program has successfully completed initial hot weather tests in Death Valley and operated Volts in mountain terrain from the Appalachians to the Colorado Rockies, including a climb up Pike's Peak.

On the vehicle development side, the next stage is to move the program to Product and Process Validation or PPV during which time vehicles will start to be built using production processes. The next mile marker for the all-important battery pack will start in February 2010 when the first GM assembled units start to be produced at its new Brownstown facility outside of Detroit.

In the last twelve months, Bill Wallace points out, GM has developed its own battery design, assembled a world-leading battery test lab and opened its own battery production facility. And to date, not a single cell has failed, despite punishing abuse tests that would exceed those encountered during real world operation, even in crashes. The photo below is of one of the first Volt pre-production vehicles to be crash tested at 65 km/hr and the battery pack -- the large orange 'T'-shaped structure in the center of the up-turned chassis -- was unaffected.

Chevy Volt crash tested at 65 km/hr shows no damage to its 16kWh lithium ion battery pack in this Fall of 2009 photos

The video at the bottom of the page shows the back being smashed in safety tests and while parts fly, Wallace notes that the pack survived and did not catch fire.

Lessons Learned To Date
As would be expected with any new engineering program, problems have cropped up, but none that Farah regards as show stoppers. As the result of its ongoing battery research efforts, GM and LG Chem, its Korean cell supplier, have "tweaked" the chemistry of the cells to improve their life expectancy. Its 80-vehicle test fleet and some 300 test battery packs have revealed things that computer models couldn't, especially the internal environment in the pack itself. They have also discovered that in the pursuit of making the ride experience as pleasing and quiet in the extended-range hybrid mode with the IC engine running as it is in the EV-first mode, engineers have had to replace off-the-shelf components they thought would work with others to keep the car as quiet inside as possible. They also have learned that the aero panels under the car were actually helping transmit road noise into the car, requiring more re-engineering.

However, none of these are that unusual in the development of a new vehicle, the GM engineers stressed and from their perspective the car is still on target for its November 2010 launch date.

The entire technical briefing and most of the media Q&A sessions are available in MP3 audio format using either of the two players in the center column of this page. Many EV World audio programs like these are also available on Apple iTunes.

EVWORLD Future In Motion Podcast

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Times Article Viewed: 8458
Published: 17-Nov-2009

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