General Motors will be able to upgrade its battery-powered 'range extender' Chevy Volt much faster than conventional vehicles due to its new technology, an executive has said.

Frank Weber, GM's global vehicle line executive for the Volt, said at an event ahead of the Chicago motor  show: "This is almost like getting software updates into your car. This is not a mechanical world. This is suddenly you get updates, improvements much more rapidly."

"So, even within a vehicle life cycle, you will see updates that are very significant," he was quoted as saying by Reuters.

GM, which expects to begin production of the Volt in 2010, has not said when it expects to roll out the second generation of the vehicle, but plans to focus on cutting the size and cost of the battery as a top priority, Weber said.

Weber also said his priorities included driving down the size and cost of the Volt's lithium-ion battery for future versions.

The 181kg (400lb) T-shaped battery pack is expected to be the Volt's most expensive element and most important component, according to Reuters. Its cells will be manufactured by Korea's LG Chem, GM said last month.

Weber told Reuters GM engineers were not focused on extending the vehicle's range beyond 40 miles (64km), a distance seen as the longest most people would drive the car on a daily basis.

"My goal is not to go from 40 to 60 (miles/64-100km) in the next generation vehicles," he said of the Volt's range. "My expectation is that the battery is equally capable, but they are half the size and half the cost of the batteries that go into the car right now."

The drive system designed for the Volt could be applied across the automaker's entire lineup over time, but that is not something Weber said he envisions now.

GM's German unit Opel has already promised a derivative called the Ampera.

"Before we talk about diversification on the portfolio side, there is enough market for a vehicle that provides this level of functionality and performance," Weber said.

The Cadillac Converj concept car GM shown at the Detroit auto show in January demonstrates the Volt system could work in a higher-cost luxury model, he added.

Weber also claimed the Volt project set GM apart from other automakers that have been developing pure battery electric vehicles, hybrid electric vehicles and plug-in hybrids, Weber said.

GM believes the Volt's battery-driven system will remain viable over several generations, and battery technology will not progress for some time to a point where pure battery electric vehicles can range hundreds of miles at an affordable price, he noted.

The automaker has taken great pains to deliver on its plan for a 40-mile pure-battery range for the Volt, down to reducing tyre friction and the battery drain from electronics such as stereos.

GM said on Tuesday Goodyear would provide new tyres that have less rolling resistance while Bose would produce an optional premium sound system that would weigh less and use less electricity, Reuters noted.

GM plans to build about 10,000 Volts in its first year and eventually hike annual output to about 60,000. The car's battery can be recharged at a standard electric outlet.

The report also noted GM had said it did not expect to make money on the first generation of the Volt, making its subsequent launches more important.