Although Firefly is still in the prototype-making stage, it has already caught the attention of several major manufacturers, including Caterpillar, where the core technology was first developed, and BAE Systems, manufacturer of the Bradley Fighting Vehicle. The Swedish corporation Electrolux, whose brands include Husqvarna, Poulan, and Weed Eater, plans to roll out all-electric products based on the battery next year, including lawnmowers and lawn tractors. Also, last month, a U.S. defense bill provided $2.5 million to Firefly for developing the batteries to power electronics on military vehicles while their engines are off during silent surveillance.

This new technology got its start after truck drivers – forced by emissions regulations to turn off their engines at truck stops and to run the air conditioning and television in their sleeper cabs with batteries – started complaining to Caterpillar that their batteries did not last long enough. The company turned to Kurt Kelley, then a Caterpillar materials scientist, and now chief scientist at Firefly Energy, for a solution.

“He had never designed a lead-acid battery before – which was the good news, because he was unconstrained by commonly held wisdom in the battery business about what you should and shouldn’t do to a lead-acid battery,” says Ovan. Kelley’s inexperience led him to find a working form of graphite foam – even though the industry had already judged foam as likely to degrade battery performance.

While the technology looks promising, Firefly is entering a competitive market. Many industry and government insiders believe that a new generation of light-weight, high-power lithium-ion batteries, which are overcoming previous safety, cost, and lifetime concerns, will replace the nickel-metal hydride batteries currently used in hybrid cars. And Firefly will also need to contend with future offerings from others, such as the University of Idaho group.