General Motors announced today that it would offer an 8-year, 100,000-mile warranty on the battery pack, the charger, and the Voltec electric drive components of its upcoming 2011 Chevrolet Volt electric car.

The announcement sets to rest potential worries that Volt owners might be stuck having to replace an expensive, high-voltage battery pack costing thousands of dollars just a few years down the road.

Volt Battery Pack

Volt Battery Pack

The warranty matches the length of time that all components affecting the car's emissions must be free of owner maintenance, as per NHTSA regulations. It rises to 10 years or 150,000 miles in the several states that have adopted California's stricter emissions limits.

While GM has not announced the replacement cost of the 2011 Volt's 16-kilowatt-hour lithium-ion battery pack, the 300-pound, T-shaped pack is widely expected to cost GM several thousand dollars to build.

Replacement parts costs are usually twice the manufacturer's cost, or more. The rest of the 2011 Volt carries GM's usual warranties of 5 years/100,000 miles on other powertrain elements (essentially the engine) and 3 years/36,000 miles on the rest of the vehicle.

General Motors Brownstown Township factory for assembly of Chevrolet Volt battery packs

General Motors Brownstown Township factory for assembly of Chevrolet Volt battery packs

The announcement came during a media event at the Brownstown Township plant where GM assembles the battery packs, using cells manufactured in South Korea by LG Chem.  Manufacturing of pre-production Volts in Detroit's Hamtramck plant began on March 31.

The plug-in 2011 Chevrolet Volt, as GM hopes you know by now, travels up to 40 miles on battery power alone. After that, its 1.4-liter gasoline engine switches on to run a generator that provides electric power to the motor that drives the front wheels.

That "range-extending" engine differentiates the Chevy Volt from the other electric vehicle launching for 2011, the Nissan Leaf. The pure battery electric Leaf has an electric range of up to 100 miles, but no gasoline range extender.

2011 Chevrolet Volt battery warranty comparison with other batteries

2011 Chevrolet Volt battery warranty comparison with other batteries

To highlight the Volt's unlimited travel and lack of range anxiety, GM drove a 2011 Volt from Austin, Texas, to New York City over the Fourth of July weekend. The so-called "Freedom Drive" covered 1,776 miles on a mix of grid power and engine-generated electricity.

GM has not yet priced the 2011 Volt, though now-retired GM executive Bob Lutz said two years ago that he expected the price to be around $40,000. Early Volt buyers are eligible for a $7,500 Federal tax credit and various state incentives as well.

First Chevrolet Volt battery pack built at Brownstown Township plant, January 2010

First Chevrolet Volt battery pack built at Brownstown Township plant, January 2010

[General Motors]