New Batteries Will Keep You Running

Dave Andrews

New battery technologies that let notebook PCs run longer without a recharge might make the transition from the laboratory to commercial products this year. However, notebook manufacturers, wishing to avoid such problems as battery overheating, remain cautious and say they will incorporate these new technologies only after careful evaluation.

One technology, lithium metal polymer, offers the possibility of high energy density (perhaps as much as double that of today's lithium ion). But lithium in its metallic form in a rechargeable battery poses safety risks: After repeated charging, the battery can short-circ uit internally. Vendors are anxious to avoid the bad press and poor customer relations related to notebooks that overheat or c atch fire.

A more promising technology, from Ultralife Batteries (Newark, NY), which may ship in commercial products later this year, uses both a solid-state electrolyte and a lithium-ion chemistry. Ultralife officials say its battery has a high duty cycle (up to 1200 recharge cycles, compared to about 500 for nickel metal hydride) and high energy density (comparable to today's lithium ion with liquid electrolyte). The battery's solid-state electrolyte allows design flexibility (batteries can be made in ultrathin rectangular shapes) and a high degree of safety (the solid electrolyte cannot leak).

Meanwhile, AER Energy Resources (Smyrna, GA) says it will soon release to computer manufacturers the first prototypes of a new version of its zinc-air battery that can run a full-size notebook up to 12 hours between charges. Previous versions of the company's zinc-air batteries, such as the PowerPro for certain Toshiba notebooks, weighed 4 1/2 pounds. But AER says the new version, thank s to a second air electrode that doubles the surface area for the battery's chemical reaction, will weigh only 1.8 pounds. Commercial products based on the new prototype might ship sometime in 1997, the company says.