Pint-Sized Power Packs

I always seem to be suffering a personal energy crisis. I can drain my mobile-phone battery dry in a day, my PDA craves a charge after 48 hours and my notebook computer beeps plaintively during the shortest airplane flight. The situation isn't getting better. Portable devices continue to sprout power-hungry features such as color screens and wireless communications capabilities. Yet the humble, overtaxed battery—without which no device would be portable—is evolving too slowly to keep up.

To anyone hauling around spare AAs and an emergency power cord, it's obvious that energy-storage technology needs a rethink. Fortunately, one is under way. Within the next 18 months, consumer electronics manufacturers, including Casio and Sony, plan to start marketing personal portable devices powered not by batteries but by fuel cells.

The impending shift is pretty radical. Unlike batteries, fuel cells don't store electricity. They generate it, via a chemical reaction between a hydrogen-containing fuel and oxygen. Fuel cells have been around for decades in exotic applications, powering satellites and spacecraft. They are being developed for commercial use in electric cars and to provide backup electricity for buildings (a truly "green" technology: their only emissions are water vapor and heat). Strapping a power plant to a mobile phone once seemed a silly idea—early prototypes for portable fuel cells were as ungainly as a pair of clogs—but miniaturization has reached the stage where consumers might buy into the concept.

Casio, for example, recently unveiled a prototype of a fuel-cell-powered laptop that looks acceptably normal. The power supply weighs half as much as existing laptop batteries and can run the machine for 20 hours at a stretch—quadruple the longevity of a fully charged lithium-ion battery. Medis Technologies, a NASDAQ-listed Israeli company, has designed a tiny, 80-g fuel cell that can sustain 20 hours of mobile-phone conversation.

Fuel cells promise to unhitch us from the electrical grid, and that's good. We'll never have to grope for a hotel-room outlet again, and no more waiting for batteries to recharge, either. But details on how costly the devices will be to own and operate are scarce, and there are potential drawbacks. Will there be maintenance hassles? (Batteries are, after all, wonderfully simple.) Casio's laptop power plant is fueled by small methanol cartridges that are replaced when the liquid is spent. Will we want to carry spare fuel cans around with us? Will airlines allow them on board? The answers to those questions will determine whether my power outages continue. Until then, intermittent blackouts are expected.