GM says battery blast at lab unrelated to Chevrolet Volt

Two employees were injured Wednesday in a lithium battery explosion that forced the evacuation of about 80 other employees at a General Motors facility north of Detroit, the Associated Press reports.

The explosion at the Alternative Energy Center laboratory at the GM Tech Center in Warren, Mich., also caused a small fire that was quickly extinguished. One worker was taken to a hospital, and the other was treated at the scene.

The Tech Center, a sprawling 1950s-era campus, is home to the battery laboratory for the Chevrolet Volt electric car, but GM said in a statement that the explosion was "unrelated to the Chevrolet Volt or any other production vehicle," according to the AP. "The incident was related to extreme testing on a prototype battery," the automaker said in its statement.

That statement is important because the Volt's safety is a touchy subject right now. The plug-in vehicle with a backup gas engine on board saw demand plunge on concerns about its battery catching on fire after a crash. But those fires occurred hours or days after the crash, so drivers or passengers were never in danger, and GM has since fixed the problem.

GM's electric vehicles have been under attack from Rush Limbaugh and other Republicans because they say the automaker was bailed out by the government and has received some loans for its advanced-vehicle research.

"Some critics will use this story to bring back to life the investigation into Chevy Volt fires from earlier this year. And while this incident deserves some scrutiny –- especially since workers were hurt –- the fact is that this is the reason why new car technology undergoes rigorous testing, to try to ensure that episodes like this don't happen on the road," said Edmunds.com senior analyst Michelle Krebs in a statement.

Electric cars use advanced batteries often made out of exotic materials such as lithium ion. While they pack a lot more power, they have to be monitored closely to make sure they don't heat up or catch fire.

Dispatchers received calls about the explosion at 8:46 a.m., and firefighters arrived five minutes later, the AP says. Firefighters found light smoke and some remaining flames, with the blast having been contained to a room.