After years in which consumers and researchers faced sharp trade-offs in weight, safety, and power for high-power batteries, promising variants are emerging. Nanotechnology is enabling a new lithium-ion battery that can unleash five times as much power as existing versions, and this summer, tool manufacturer DeWalt, of Baltimore, MD, plans to sell a line of 36-volt cordless tools that use it. Progress in the field even includes an upgrade to the age-old lead-acid battery.

The new lithium battery -- developed by A123 Systems of Watertown, MA, and based on the work of Yet-Ming Chiang, a materials scientist at MIT -- is not only more powerful but also recharges to 90 percent capacity in five minutes and lasts through ten times as many recharging cycles as conventional counterparts, the company says. The battery will initially be used in professional-grade tools where bursts of high power are at a premium. But the technology could lead to battery-operated versions of power-hungry devices like vacuum cleaners, lawn mowers -- even hybrid cars.