As tighter emission control regulations push the automotive industry to create the hybrid and electric fleets of the future, automakers are increasingly focusing their attention on new technologies to meet the increased power demands of those vehicles. Lead-acid batteries may not be mentioned often when automakers talk about the hybrid and electric car fleets of the tomorrow but they remain a core part of emerging designs due to cost efficiency.
"Toyota does believe that hybrid is the future. It sounds a bit dramatic, but going forward it is our core strategy," Jaycie Chitwood, manager of alternative technology vehicles at Toyota Motor Sales USA Inc., said.
Part of Toyota's strategy to deepen market penetration is to offer more hybrid models and hybrid versions of conventional vehicles, as well as to continue paring the premium customers have to pay for hybrids. While Toyota doesn't make a conventional version of the Prius, the basic 2010 Camry starts at $21,195 while the hybrid version of the sedan is priced at $26,900—a premium of $5,705, or nearly 27 percent, over the conventional model.
"Battery technology is the biggest challenge facing all electrified vehicles," Gil Portalatin, hybrid applications manager at Ford Motor Co., said. The Dearborn, Mich.-based automaker has been selling hybrids since 2004.
At the luxury end of the spectrum, Mercedes-Benz, part of Germany's Daimler AG offers two hybrid models in the United States: the ML 450, a sport utility vehicle with a nickel-metal hydride battery, and the S400, a large luxury-class sedan powered by a dedicated lithium-ion battery. The price difference between the S400 hybrid and the gasoline-powered S550 is harder to measure: while the hybrid is cheaper at $87,950 vs. the S550's $91,600 price tag, the latter is slightly roomier—and can go from zero to 60 in 5.4 seconds compared with the hybrid's 7.2 seconds.
The industry-wide push to make hybrid vehicles is far from altruistic. The European Commission last April tightened its emission standards to 130 grams of carbon dioxide per kilometer, with 65 percent of each automaker's new vehicles to be in compliance by 2012. Those who fail to comply face penalties.
President Obama followed Europe's move in May, mandating a corporate average fuel economy standard of 35.5 miles per gallon by 2016, or a 30-percent increase in fuel efficiency from previous standards, fast-tracking the regulation originally set for 2020.
Reaching those targets will require a wide array of technological advances and while some OEMs are betting solely on diesel or hybrid technology to meet the new standards, Mercedes is pursuing a three-pronged approach. The company is building hybrids, pioneering innovations—like the clean-diesel engine it introduced in Europe and the United States—and building more-efficient gasoline-powered engines. Mercedes also is working on hydrogen fuel cell technology that it hopes to bring to market.
"We have a philosophy that there's not just one solution," a spokesman for Mercedes USA LLC, Montvale, N.J., said. The multifaceted approach helped the German automaker bring the first mass-produced lithium-ion battery powered car to the market in the form of its S400 sedan. "The lithium-ion battery is around the same size as you'd find in a traditional car and it sits in the engine compartment," the spokesman said. "Then we have a lead-acid battery in the trunk for powering the accessory functions."
Although lead-acid batteries may seem like an afterthought in the futuristic space inhabited by hybrid electric vehicles, the time-tested, conventional batteries are to be found in every commercially available hybrid on the market.
The difference is "they serve two completely different purposes in the vehicle," Toyota's Chitwood said. While nickel-metal or lithium-ion batteries provide motive power, lead-acid cranks the engine and runs the vehicle's electrical system and accessories.
"For the purpose the 12-volt battery serves, lead-acid is by far the least-expensive option out there," Chitwood said. "I don't see a scenario where the cost of nickel-metal would be reduced to parity of lead-acid. In order for another battery technology to take the place of lead-acid, the costs would have to come down by several orders of magnitude."
When it comes to the cost of nickel-metal hydride batteries, Toyota should know. The company chose to develop its battery technology in-house, spending millions on research and development. "Because we're now relying on the battery to provide power to drive the vehicle and it's so intimately integrated in the vehicle, we think of it as a core competency," Chitwood said.
Toyota now sells its batteries through an alliance with Panasonic Corp. to a wide range of other OEMs, including Nissan Motor Co. Ltd., Honda Motor Co. Ltd. and General Motors Co.'s Chevrolet, Cadillac and GMC operations.
It is in the emerging market for high-technology batteries that lead-acid battery makers will likely find their next growth opportunity. While lead-acid will continue to be used in hybrids, the value-added opportunities lie in meeting new technology demands. Mercedes-Benz, for example, sources its lithium-ion batteries from the partnership between Johnson Controls Inc. and France's Saft SA.
But having production closer to home would likely benefit research and innovation. "Locally mass-produced battery cells would benefit all electrified products," Ford's Portalatin said.