General Motors believes it has dealt with one of the biggest obstacles in the way of making electric cars a reality: the battery technology. And it has reaffirmed its commitment to put the Volt, on course to be the first plug-in car from a major manufacturer, on sale in 2010.GM product chief Bob Lutz said, “It’s not the battery technology that’s taking the time now; it’s all the other stuff involved in developing the car.”Unlike hybrids such as Toyota’s Prius, the Volt does not rely on an internal combustion engine for propulsion, making it the first full-size fully electric car that can be recharged using mains electricity.GM is working with two electronics firms on the lithium-ion batteries that the car will use: Korea’s LG Chem and America’s A123 Systems. It looks like early versions of the Volt will use a small petrol or diesel engine to charge the battery, with fuel cells coming later. Because of the way the Volt is designed, the generator can easily be changed to suit different markets — an ethanol-powered engine for Brazil, for example, or a small diesel for Europe. This is the core principle of GM’s E-Flex system, launched by the Volt concept last year. The car’s design will be different from the concept’s, because of the need to exploit aerodynamic improvements to maximise fuel efficiency. The concept’s low roofline has been raised to make the car more practical; it will be a five-seat family car, based on GM’s next Delta platform, which will also underpin the new Astra. Delta has been designed from the outset to incorporate fuel cells.Lutz said one of the hardest jobs of designing an all-electric vehicle from the ground up is developing all the sub-systems, such as cooling for the batteries. “The first-gen Volt is going to have nightmare plumbing,” he said. “You don’t want to fix this thing at home.” Then there are the complex electronics needed to co-ordinate battery, generator and motors to make sure the battery stays charged. GM is working on a system that can detect when the battery is low and automatically start the generator to charge it. Energy conservation is vital in a car powered by electricity, so the Volt will use low-consumption ancillaries designed for the car. Air-con, wipers and even stereos are being redesigned to use less current. “These components are going to be expensive in the first generation, but cheaper in the long run,” said Lutz. While development is on target — the first prototype drives are due in June — there are questions about how much the car will cost. Originally GM mentioned a US price under $30k (£15,000), but recent comments by Lutz suggest that it might cost more.