The cars worked well, but all the power electronics that were needed to control the two power systems were heavy and prohibitively expensive. Instead of treating the lead-acid batteries and supercapacitors as separate systems, Lamb's team decided to eliminate the need for all external electronics and instead build the supercapacitors directly into the battery. Essentially, one of the plates (the negative electrode) in the lead-acid battery was made half of lead and half of carbon, turning the battery into a supercapacitor-lead-acid hybrid.

CSIRO brought the design to Japanese battery manufacturer Furukawa Battery Company, which saw potential in the technology. After three years of collaboration, the two organizations determined that they could manufacture the UltraBattery much like conventional lead-acid batteries and at similar cost.

Meanwhile, Axion Power International, in New Castle, PA, has also developed a new type of lead-acid battery. Edward Buiel, chief technical officer with Axion, says that lead-acid batteries can play a significant role in the future of transportation and energy supply. Unfortunately, he adds, the automakers don't see the potential. "If you're not lithium-ion or nickel-metal hydride, they're not interested. It's frustrating."

Buiel says that the typical cost of a nickel-metal hydride power pack is $2,000, and close to $5,000 retail. "A comparable lead-acid could be in the range of $1,000 in low volume, and significantly less in high volume," he says. "It's a battery where the consumer could see enough fuel savings for a payback in a year or two."

Despite the reluctance of the auto industry to embrace the technology, Lamb is convinced that by 2010 there will be some Japanese-made hybrid cars on the market offering the UltraBattery option.

However, Axion might have something to say about it. "We definitely think this technology is an excellent choice for hybrid-electric vehicles," says Buiel. "There's a lot of intellectual property in this area, and most of it is owned by Axion. Obviously, if we feel somebody violates our patent, we will defend that vigorously." He says that Axion plans to launch a demonstration project in North America this year that will test dozens of hybrid vehicles retrofitted with its lead-carbon batteries.