In general, battery recycling has a positive reputation. More than 97 percent of lead-acid batteries are recycled, according to the Web site of the Chicago-based Battery Council International (BCI). This compares to 55 percent of aluminum beverage cans, 26 percent of glass bottles and 71 percent of newspapers.

The BCI reports on its site that the average new lead-acid battery is composed of 60 percent to 80 percent recycled lead and plastic.

A new kid on the block may present an emerging challenge in battery recycling, however. As nickel-metal hydride (NiMH) batteries--the rechargeable power source for hybrid electric vehicles (HEVs)--are popping up in the auto market with increasing frequency, so are issues concerning how to best recycle the emerging commodity.

GETTING IT TOGETHER. Only a few years ago, gas-electric hybrid vehicles were more a luxury for the wealthy and curious than an everyday vehicle for the average driver. But since Toyota Motors brought the hybrid Prius to the U.S. market in 2000, technology has improved and the vehicles--as well as the batteries that power them--have become more affordable. According to the Automotive Recycling Association, Fairfax, Va., Toyota plans to introduce three more hybrid models by 2006. (A portion of the Toyota Prius hybrid engine is pictured at right.)

By that same year, other auto manufacturers, including Ford, Lexus and General Motors, plan to put out hybrid models to join Toyota's Prius and Honda's Insight and the hybrid model Civic. More HEVs on the road will equal more NiMH batteries that will eventually make their way into recycling streams.

Of course, it could take a decade until the batteries make their way to recyclers in any sizable quantities, says Shane Thompson, international accounts manager for metal recycler Inmetco, Ellwood City, Pa. Thompson says most NiMH batteries are expected to last between eight and 10 years, or 100,000 miles. Eventually, Thompson says, manufacturers hope to have batteries that can last the life of the car. But even the current life expectancy is about two years longer than the six-to-eight year life expectancy of a lead-acid auto battery.

Thompson says recyclers are working to get an infrastructure in place to handle the dismantling and recycling of NiMH batteries before the early generations reach their end of life. Other rechargeable batteries, like nickel-cadmium units for cell phones and lap top computers, have long enjoyed an established handling process held up by state regulations that encourage voluntary recycling programs. Lead-acid auto batteries share the same advantage. But NiMH batteries are still too new to have such a solid system in place, Thompson says.

"It's looking like the cars are going back to the dealers (at the end of life), but it isn't a firm system," Thompson says. He says dealers will need to get instructions about how to safely handle the batteries and prepare them for storage and shipping.

But the fledgling recycling process for NiMH batteries is already starting to take the shape of the system that's in place for handling more traditional lead-acid auto batteries, according to environmental consultant Richard Paul.

He says NiMH batteries, like their lead-acid counterparts, are first removed by the automotive dismantlers--one step away from the consumer. "There's not a great deal of difference there," he says. "Just like lead-acid batteries, the key to safely removing an NiMH unit is to simply never try to cut or remove the battery with the power on."

Paul says the same concerns with storing and transporting any auto battery also apply to nickel-metal hydrides. As with all batteries, dismantlers need to be wary of the risk of electric shock when removing NiMH batteries, according to Bill Duff, corporate manager of the environmental coordination office of Toyota Motor Sales Inc., Torrance, Calif. "Dismantlers should understand the amounts of chemical energy stored in these batteries," Duffsays. "They should not attempt to 'deactivate' them without proper safety training and safeguards."

It is at the next level--the recycling facility--that things get a little more complicated.

For one thing, the battery cells contain potassium hydroxide, which is highly corrosive and can be damaging to living tissue, Thompson says.

According to Duff, understanding the nickel-metal hydride battery's unique chemical makeup is central to recycling it safely, even if it means putting the extra expense into developing special training programs at the facilities where these batteries are managed.

SEEING GREEN. Nickel is the real prize inside the NiMH battery, says Bruce McKean, director of product stewardship for the Nickel Institute, headquartered in Toronto. And its high price might be enough to encourage companies to take the plunge and explore recycling NiMH batteries. "Nickel is expensive; it doesn't require an artificial motive (to recycle)," he says. "There's enough value there where it almost pays for itself." The London Metal Exchange has the average monthly-price of nickel towering over many other nonferrous metals at $14,045.45 per metric ton, as of late November 2004.