If it's portable and electronic, it needs batteries. One of the byproducts of
the silicon revolution has been the steadily growing appetite for portable
power for GPS receivers, personal digital assistants, and other mobile
devices. And, despite the best efforts of engineers around the globe to come
up with a better mousetrap, the humble battery will be around for a while —
it's a very mature technology with more than 100 years of successful
application.

However, batteries aren't perfect. Sooner or later, they need to be replaced
or recharged. Because it typically takes hours to recharge a totally drained
battery, radio manufacturers are incorporating techniques to stretch power
lifecycles. For example, RELM Wireless's Project 25-compliant DPH line of
VHF radios is capable of operating between 20 to 30 hours by using a
high-capacity NiMH battery and switching on several power-save features.

“When we developed the [DPH] radio, we borrowed from our existing
low-current technology,” said Jim Spence, RELM's executive vice president of
engineering. “The components have been honed for the cell-phone market, so
they are extremely low current.” A programmable battery-save mode powers
the radio off, except for a “listen” mode that activates a couple of times per
second to detect incoming traffic.

Another option is fuel cells, which offer clear advantages over batteries,
according to Gregg Makuch, director of marketing for Neah Power Systems.

“The real difference is that the relationship between a battery and runtime is
linear, whereas with a fuel cell, it is non-linear,” Makuch said. “You carry five
batteries for five times the run time. Or, you can carry a single fuel cell and
a couple of cartridges, each half the size of a lithium battery — [they're]
smaller, lighter, and [you] can pop them in and out instantly.”

While a few manufacturers have promised small fuel cells by the end of
2004, industry analysts think it will be somewhat longer.

“Safely speaking, I would say mid-2005,” said Sara Bradford, industry manager,
power supplies and batteries group, at Frost & Sullivan. “Toshiba just
delayed its [product] delivery until then. … As this race is volatile and
completely depends on beta testing prototypes, I cannot say who will come
out first.”

Frost & Sullivan research estimates the market for fuel cells for use in
mobile devices could reach as high as 10 million units by 2010. In contrast,
the rechargeable battery market for the same devices is expected to be 1.79
billion units.

A typical micro fuel cell uses methanol, an alcohol-based fuel that can be
made from a variety of materials, including garbage, trees, and seaweed,
though most methanol is made from natural gas. A quarter of the world's
supply of methanol is produced at 18 plants in the United States, where more
than 2.5 billion gallons are processed annually, according to the Methanol
Institute.

Power in a methanol fuel cell is generated by passing a methanol/water
solution along with oxygen from the surrounding air across a thin proton
exchange membrane (PEM) — covered with a thin layer of platinum-based
catalyst — between two electrodes. The resulting chemical reaction across
the membrane breaks down the methanol, generating electricity along with
water vapor and carbon dioxide as byproducts. Manufacturers have
demonstrated fuel-cell prototypes that use from 3% to 30% methanol, with
plans to try to boost concentrations up to 40% to 60% in the future. Higher
concentrations provide more power but also create the challenge of
manufacturing a membrane that operates efficiently without letting too much
methanol seep through the membrane too quickly.

MTI MicroFuel Cells has a very ambitious agenda with programs targeted at
the military and consumer electronics markets. MTI's star product is a
replacement for the military's standard BA 5590 disposable lithium battery.
Using the company's proprietary technology, prototypes have been
demonstrated that operate on fuel consisting of 50% methanol, with an
ultimate goal of operating on 100% methanol.

In November 2003, MTI announced an agreement with Harris Corporation to
integrate the fuel cell with Harris radios as a direct replacement for the
battery or as a battery recharger. The company also has entered into an
exclusive, multi-year partnership with Gillette and its Duracell battery
division for the development of a fuel-cell system and refills for
“high-volume consumer markets.” MTI Micro will build the actual fuel cell
system, while Duracell will be responsible for fuel cartridge refills.
Gillette has invested $1 million with an option to invest up to $4 million more
if certain performance milestones relating to power output and weight are
met.

Meanwhile, Neah Power Systems is taking a creative approach to fuel cell
development, using etched silicon as the structural membrane material to
create more surface area for reactions to take place.

“Silicon is a very durable and stable material and isn't going to break down
with higher concentrations of fuel and oxidant,” Makuch said.

Neah anticipates shipping its first fuel cells to power PCs in late 2005 or
early 2006.The company will use a closed-loop cartridge that includes an
oxygen source in the form of hydrogen peroxide and captures waste water
vapor and carbon dioxide in the cartridge, enabling it to be operated in
harsher environments. First generation PEM designs intake air to provide
oxygen for reactions and vent water vapor and carbon dioxide — two paths
where unwanted material such as dust and excess water can enter and
interfere with the cell's operation.

“In volume production, we expect these cartridges to cost a couple dollars
per cartridge or less, depending on the size and application,” Makuch said.
“The good news is that the core ingredients are relatively inexpensive —
methanol is 50 cents a gallon. Plus, mass production seems feasible — heck,
Bic produces 4 million lighters a day.”