GM explores Volt battery design changes

December 2 - General Motors Co (GM.N) is exploring design changes to the Chevrolet Volt battery to address issues raised after federal safety officials opened a probe into the plug-in electric car, a top executive said on Friday.

"We are looking to say, 'Are there some design changes we can make, something even more robust in this location or that location or with this component,'" said Mary Barra, GM's global product development chief. "If we have to do something, we will.

"The one thing you don't want to do is jump to conclusions," she added.

GM said on Monday it would offer loaner vehicles to about 6,000 Volt owners as it works with the National Highway Traffic Safety Administration on ways to reduce the risk of battery fires breaking out days after crashes involving the car.

That was in response to a decision last week by NHTSA to open an investigation into the safety of the Volt's battery pack. A lithium-ion battery pack in a Volt that went through a crash test in May caught fire three weeks later at a test facility in Wisconsin, according to NHTSA.

GM Chief Executive Dan Akerson told Reuters on Thursday the U.S. automaker might redesign the Volt battery.

GM executives have said the Volt's battery pack would be safe during and immediately after any crash and that problems were not linked to any flaw in battery cells supplied by South Korea's LG Chem Ltd (051910.KS).

Barra, speaking at an Automotive Press Association event, declined to say how long she thought the NHTSA probe might last, other than to say officials with the federal agency and GM are moving as quickly as possible.

She said there are a "few avenues that we think could increase the robustness for this specific condition," but added the NHTSA probe was still in early stages.

GM will change as needed the Volt's battery design, whether in current or future models, but any alterations would be thoroughly tested, Barra said.

She reiterated the Volt was safe and well designed, and its rollout was not rushed. Barra said if owners have concerns about the vehicle's safety, GM would buy back the cars in the appropriate cases to protect customer satisfaction.

Barra said she is not worried that GM would be forced to change the Volt battery in a way that would result in a heavier, more expensive and less fuel-efficient design.

"We understand one of the very important premises of the Volt is the EV (driving) range and we plan to protect that," she said.

The Volt has a gas-powered 1.4-liter engine to provide additional range after it has run about 40 miles on a fully-charged battery. The plug-in hybrid costs $40,000 before a $7,500 federal tax credit.

Barra also said the NHTSA probe and Volt battery issues had not affected the planned rollout of any EV-related product programs GM has announced.

In October, GM said it would introduce an all-electric version of its Chevy Spark minicar that will debut in 2013, with a battery supplied by A123 Systems Inc AONE.O. In August, GM said it would build a Cadillac ELR luxury coupe based on Volt's plug-in hybrid technology.

(Reporting by Ben Klayman in Detroit)