Portable power? Soldier devices create voracious demand for better batteries.

The old battlefield expression, "praise the Lord and pass the ammunition," may soon be "praise the Lord and pass the AA batteries." That is, if dismounted soldiers wired up with the latest electronic gear don't see improvements in power technology soon, Army officials are saying.

Night vision goggles, Sure Fire lights, global positioning system receivers and communication gear are a few of the 12 devices creating what some military officials are calling the "Christmas tree effect." Gadgets are hanging off infantrymen like ornaments.

"Just since the war started, soldier power requirements have just gone off the chart," said Jim Stone, deputy director of combat developments at the Army Infantry Center.

Dave Schimmel, a contractor who serves as hardware systems lead engineer at the Army soldier program executive office, said he is desperate to reduce the number, types and weight of batteries that the so-called "digital soldier" must lug while on patrol.

"We're continuously looking for more power sources," Schimmel said. "We're not tied to any one person, one company, one organization, one lab. We'll take from the Marine Corps. We'll take from the Air Force. We'll take from industry. It doesn't matter to us. We really don't care. We just want power sources."

The Army is signing up for new portable technologies without taking into consideration the battery factor, Stone said at an Institute for Defense and Government Advancement tactical power conference.

Stone is serving as chairman of the newly formed soldier power integrated concept team, which will attempt to get a handle on the problem. Small arms or tactical communications divisions, for example, are not coordinating on the battery issue.

"Vendors come to [us] and say 'I've got a flashlight that will send a beam 10 kilometers,' and my guys will sign up for it. We've got to get that under control," Stone said.

The power integrated concept team will act as a gatekeeper to harness the growing demands for power needed when soldiers are dismounted on brief patrols, or on extended missions that last several days.

Stone tossed out a couple statistics to show how acute the problem has become.

An infantry platoon of 40 soldiers on a 72-hour mission requires about 65 batteries per man. Outfitting a brigade on a five-day mission costs taxpayers $1.5 million in batteries.

For infantrymen loaded down with more than 100 pounds of gear, every ounce counts. Compounding the problem is a soldier's tendency to take more than he needs "just in case," officials said.

The two wars point to the complexity of the issue, said Chris Bolton, chief engineer of the Army power division at the communications-electronics research, development and engineering center (CERDEC).

Iraqi patrols tend to be short, less than a day, or a few hours. In Afghanistan, soldiers can set out for three days or more.

"Which is the more important one?" he asked.

Rechargeable batteries might be fine for short patrols. But soldiers on longer missions lasting several days want the option of shedding disposables to lighten their load.

And while 65 batteries per man is an average, different jobs in a platoon call for different amounts of batteries. A communications specialist, who must keep in touch with a command headquarters, will require more power than a grenadier. Radios need the ability to send short bursts of power.

One major concern is a lack of uniformity, the engineers said. The approximately 12 systems soldiers can carry on their person use nine different types of batteries operating independently from each other. That raises the dangerous scenario of a soldier having to stop in the middle of battle to swap out a set of batteries on his communications systems, then a few minutes later, taking cover to load new batteries in his weapon scope.

They "can't expect the enemy to just stop shooting," Schimmel said.

The obvious solution is having one power source linked to all the electronic systems. There are many technologies that could serve as the power source, said Schimmel, who added that he was "agnostic" as to what they might be.

Hydrogen fuel cells are one possibility. They are an electrochemical device that combines hydrogen and oxygen to make electricity. The oxygen comes from the air, but the hydrogen must come from a second source--most often common fossil fuels.

Methanol-based fuel cell concepts have received some Army funding. The liquefied fuel can be distributed in cartridges or bladders. Schimmel said systems using bladders are an attractive idea because the solder is shedding weight as the fuel becomes depleted.

At least two companies are working on methanol fuel cells for the military. Ultracell Corp. of Livermore, Calif., delivered several units to CERDEC last year. They underwent testing at Fort Belvoir, Va., in support of the Land Warrior program and the Army's future ground soldier system, according to a CERDEC statement. The Ultracell units weigh less than one kilogram and are designed to provide 20 watts of power throughout a 72-hour mission.

EFOY, a German company, has received funding to develop its methanol-based fuel cell. It uses cartridges to deliver its fuel to a 1.3-kilogram unit. The company says it can reduce the battery load by 80 percent and provide 24 watts of continuous power.

Protonex, of Southborough, Mass., is offering a dry fuel cell cartridge that requires the soldier to combine water with sodium borohydride to create a chemical reaction to provide power.

Three cartridges weighing 5.1 kilograms will last 72 hours and provide 30 watts of continuous power. The system can operate on saltwater and urine when water is scarce.

"Nobody wants to carry a gas cylinder," said Protonex vice president Greg Cipriano of his methanol rivals.

An old concept receiving a new look from CERDEC is the Stirling engine. Invented in the 1800s, the engine moves by heating gas sealed in a compartment. The change in pressure causes the gas to expand and a piston to move up and down, thus creating power.

As long as such concepts are mature and ruggedized for the harsh military environment, Schimmel said the Army is interested in hearing what industry has to offer.

"If you can carry it, wear it, and bring it with you to the mission, we're interested in it," he said.

However, such units must be as small as possible in order to mitigate the Christmas tree effect. Soldiers don't want another big box hanging off their uniform. "Real estate on a soldier is precious," he added.

The ability to operate under all conditions is essential. Some industry representatives have come to him with ideas for fuel cell systems, but with caveats. For example, don't let the unit get wet. That's not going to work, he said.

They have to work from the Attic to the hot deserts of Iraq, and when crossing rivers. As any consumer who has tried to use a lithium ion battery in extreme cold knows, it can go dead. Other batteries degrade in extreme heat.

Meanwhile, there are other concepts that don't require fuels, all in various stages of development at CERDEC.

Photovoltaic solar cell rechargers can be used as long as they can be exposed to the sun for six to eight hours. Soldiers have complained that these systems take too long, though.

Special Forces have field tested a hand-cranked generator that can recharge batteries used to operate satellite phones and personal digital assistants.

There has also been research into using the body's natural movements to generate power. For example, the piezoelectric heel-strike method generates power through a system installed in a boot heel. Each step creates a rotary motion within the device that generates power.

In the near future, it's a AA world, CERDEC officials said.

Current plans call for the use of military and commercial standard batteries through 2010, Stone said. Hybrid power systems, using sources including fuel cells and standard batteries, are to be introduced in the 2010 to 2014 timeframe. At that point, the Army hopes to have one common battery on the soldier powering all his systems.

Beyond 2014, CERDEC is hoping to have one fuel source, fuel cells or portable Stirling engines, for example, powering all portable systems.

Meanwhile, cutting edge technologies will continue to create headaches. Devices that can see through walls or counter-sniper systems will only tax battery consumption further, Stone said.

"We know that our power requirements are going in the wrong direction," he said.

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