So says US-based auto supplier Johnson Controls, which estimates that start-stop systems can save between five and 12% of fuel.

The company told an analysts' meeting this week that, globally, start-stop will be used in 52-55% of new vehicles built in 2016, up from 8% in 2010. That means nearly 25 million vehicles will be built with the advanced batteries allowing start-stop in 2016, up from seven million in 2011.

JCI's power solutions president, Alex Molinaroli, said overall start-stop battery sales will be 35 million within five years, including batteries not put into new vehicles.

The expansion of start-stop technology is driving demand for newer batteries, called absorbed glass mat.

'In this competition, start-stop has gained share because consumers perceive real value from the application and are moving it forward up the adoption curve,' Kim Metcalf-Kupres, vice president of global sales, marketing and strategy, told analysts.

The company is spending $138.5m to convert an Ohio battery plant to an absorbent glass mat factory, its first such US plant. Production of the start-stop batteries will begin in spring 2012.

The widespread adoption of start-stop system could have an impact on growth of EVs too, the company said, because consumers can use a fuel-saving alternative without having to contend with a different infrastructure.