GM goes electric - The timescale

Despite spending much of 2007 talking up its E-Flex system, and using concepts such as the Chevrolet Volt and a new model to be revealed at this September's Frankfurt motor show to promote the idea, GM is still some way from having a battery-powered car ready to go on sale.

With the first generation of battery technology still to be tested, GM shies away from setting any fixed dates for a launch.

With testing not due to begin until early 2008, though, it will be 2010 at the earliest before anything reaches the forecourts.

However, GM is open about the goals it must achieve before any E-Flex car is sold.

It wants to achieve a 55-60km (34-37-mile) range from a battery that can be charged in just over three hours, and it will extend that range to 775km (481 miles) using a small-capacity petrol or diesel generator that will power the battery when its basic charge runs out.

The battery will operate at full capacity for at least 10 years and will be replaceable.

GM estimates that the higher purchase costs caused by the development and manufacture of lithium-ion batteries will be negated in that time by the frugal running costs.

At present, the diesel costs of 100km (65 miles) of motoring are estimated to be four times the amount required to buy electricity to power a car over the same distance.

A hydrogen fuel cell-powered generator is also under investigation. Although its range would be reduced to 250-300 miles, it would be emission-free for that distance.

'People say the automobile changed the world - well, I personally believe that E-Flex will change automobiles,' says Schlumberger.