For a three-day mission in Afghanistan, the average soldier lugs a minimum of 20 pounds of up to seven types of batteries — from small AA’s for night-vision goggles to brick-size packs used in tactical radios. Some troops tote even more — up to 35 pounds — for specialized equipment. An infantry battalion on a one-year deployment typically burns through $150,000 worth of batteries.
Power and energy are essential weapons of war. Troops deploy with more electronic gear than ever: Flashlights, radios, GPS receivers, computers, cameras, mp3 players, small robots, all of which have to be constantly charged.
But these growing energy demands are bad news for the U.S. military for a number of reasons. For one, they pose enormous burdens on the logistics support system, which endangers U.S. forces. In Afghanistan, supply trucks heading to military outposts must travel on hazardous, mine-infested roads. The weight of the extra batteries also is causing physical harm to soldiers, putting them at risk of musculoskeletal injuries, some with long-term consequences.
Freeing troops from the tyranny of batteries has taken on more urgency in recent years as the overall weight of a soldier’s gear has ballooned upwards of 130 pounds. Curbing the demand for batteries is one piece of a larger effort by the Army and Marine Corps to bring down the weight from 130 to less than 50 pounds.
Another significant downside to the excess load is that it makes soldiers less effective in combat, officials said.
“Soldiers are very concerned about the weight” they have to carry, said Lt. Gen. Michael Vane, director of the Army Capabilities Integration Center. “Unfortunately we’re starting to see it in medical reports,” he said in an interview. “Soldiers who have been carrying weight a number of years are seeing long-term injuries.”
The Army and Marine Corps both have launched campaigns to address the problem. They are seeking to adopt more efficient sources of energy as well as contain the demand for power.
Unburdening troops from heavy loads also is seen as an important element of the military’s strategy to prepare for future wars. The Marine Corps, for instance, wants to be able to deploy company-size units that can operate independently for several days, far away from the battalion or brigade headquarters. But that vision will be tough to achieve if troops are overloaded with stuff, said Brig. Gen. Frank L. Kelley, commander of Marine Corps Systems Command.
The idea is to “disperse our forces so we’re not targeted,” he said at a Worldwide Business Research industry conference. “But you don’t make them heavy. … I’m worried about our war fighting concepts and the fact that the technology today is inhibiting us from really being able to operate the way we want to in the future.”
With 120 pounds on his back, an infantryman is “not very tactical or maneuverable,” said Lt. Col. Rick “Silky” Schilke, deputy director of the Marine Corps’ Expeditionary Energy Office.
“That’s a problem not just at the individual but at the unit level,” he said at an Institute for Defense and Government Advancement presentation. “We need more autonomy and self sufficiency for units. You have to have communications and protection at the small unit levels,” he said. “That equates to power and weight.”
There may be times when, because of the supply tether, troops “can’t push far into enemy territory,” Schilke said. The average multiband “manpack” radio, for instance, requires 216 AA batteries every two days if it’s operated continuously. Larger electronic devices such as robots or sensors usually have large battery packs that typically are recharged by vehicle power. “We’re burning a lot of fuel in idle mode,” Schilke said.
The Defense Department has spent at least $2.1 billion on power sources between 2006 and 2010, according to the Government Accountability Office. But that investment so far has not resulted in significantly more efficient and lighter batteries for soldiers. The best chance for a breakthrough right now lies with solar power.
Marines in Afghanistan — whose airplanes, vehicles and generators devour 200,000 barrels of fuel a day — see solar energy as the ticket to both slimming down troops’ backpacks and also the overall fuel demand.
In the Sangin District, India Company, 3rd Battalion, 5th Marines went 90 days without the usual daily resupply of batteries. Instead, they recharged their batteries with solar roll-up blankets. They have been satisfied by the results so far, officials said, and are finding new ways to replace diesel generators with renewable power sources.
“It’s a culture change for us,” Commandant of the Marine Corps Gen. James Amos said at a recent congressional hearing. “It’s catching on, “ he added. “It’s a good day when captains and corporals get excited about not having to carry extra batteries up into the mountains on patrol.”
Whether these early experiments translate into wholesale reductions in troops’ battery loads is still uncertain.
In most areas where U.S. forces deploy, sunlight is plentiful. But garnering that energy will require not only better solar power collectors but also substantial improvements in storage devices, namely, batteries. A shift to renewable energy would require that soldiers embrace rechargeable cells. That, in itself, may be a bridge too far, considering that most soldiers prefer the throwaway type.
The physics of improving batteries seem rather simple — packing the most amount of energy at the lowest amount of weight. But for most military applications, the most efficient batteries are disposable. That issue alone creates a significant disadvantage for solar energy efforts, as it will require soldiers to trust rechargeable batteries.
Before they go on a mission, soldiers typically want fresh batteries, and they don’t want to have to bring them back. Another nuisance about rechargeables is that each electronic gadget requires specific chargers and batteries that are made by different companies so soldiers end up with a rat’s nest of wires and connectors.
“Soldiers don’t like to recharge because they don’t have portable means to do so, and they have to go back to their base,” said Paul Dev, an energy expert at D-STAR Engineering. Soldiers do not like to carry their dead batteries for an entire mission. Dev said one of the drawbacks of current rechargeables is that they have two-thirds to one-half the energy density of disposable batteries.
Improving the energy density is essential to making the shift to renewable sources, Schilke said. “We have to learn how to harvest more solar energy,” he said. “We also have to get more efficient at storing.”
Commercial manufacturers produce high-performance rechargeable lithium-ion batteries, but most cannot meet the military’s stringent requirements. “New technologies coming out don’t work well in extreme temperatures,” said Riad Nakhleh, director of product solutions at Palladium, a supplier of high-tech battery packs. “We have lighter, smaller, more powerful batteries,” he said. “But lithium-ion batteries only work well between minus 20 and 60 degrees [Centigrade].”
At military laboratories, there are projects under way to develop improved rechargeables. But it could be years before they are mass produced and available to deployed units. At the Army’s Research Laboratory, scientists designed what may be the most advanced lithium-ion rechargeable battery that meets U.S. military technical specifications. The lab in February hosted a “Battery Technology Industry Day,” in an effort to find a suitable manufacturer for this new battery.
The lab owns the patent and is now looking for a company to produce the new battery, said Cynthia Lundgren, chief of ARL’s electrochemistry branch in the sensors and electron devices directorate. “These improved batteries would have increased density. They would last longer,” she said in an interview. That means fewer batteries would be required, she added.
If this program is successful, Lundgren said, it would mark a major step toward lightening the load for soldiers, she said.
Batteries have been around for more than a century, she said, but “progress has been painfully slow. We’ve been making incremental improvements over time.”
One of the technological bottlenecks in lithium-ion batteries — which have the highest density of any others currently available — has been the ability to increase the voltage without compromising safety. Military batteries, unlike those used in the civilian world, must function in extreme temperatures. “We were able to design materials to make batteries stable at 5 volts, which is a 30 percent increase in energy density,” said Lundgren.
Current rechargeable lithium-ion batteries found in cell phones, iPods and laptops have a cell voltage in the range of 3 to 4 volts.
ARL’s new generation of batteries could be charged with solar energy, but they would require a special kit. The Army’s Natick Soldier Center has created a solar pack that can be used to recharge batteries, Lundgren said. For any type of renewable energy charge, she said, “You have to have the right power manager. You can’t just plug it in.” Lithium-ion batteries, particularly, have to be charged with a certain protocol, she said, because they can be hazardous or catch on fire if they are overcharged.
Industry experts contend that safety concerns about lithium-ion have been overblown. Worries about the safety of lithium-ion “don’t reflect the current state of the technology and industry,” said Josh Prueher, of Earl Energy. No other battery chemistry can deliver the weight and size the military wants, he said. For the military, he said, consolidating to one chemistry would be beneficial, as opposed to the six different ones currently in the U.S. inventory.
The Army Research Laboratory is researching lithium-air batteries, which have higher energy density and could last three times longer than lithium-ion, but cannot be recharged. Lithium-air has the highest density of all throwaway batteries — 145 watt-hours per kilogram in lithium-ion compared to 500 in lithium-air, Lundgren said. This technology is still in its embryonic stages, and has not been adopted by the commercial industry, she said. “We have a couple of patents.”
It takes time to mature this technology, she said. “You can’t schedule invention.”
Scientists also have been working on fuel cells. After years in laboratory limbo, fuel cells might eventually play a niche role in military energy as battery rechargers. Lundgren said soldiers could reduce their load by one-third if they adopted fuel cells. They would be powered by methane or other safer alternatives to early hydrogen-fueled variants.
Seeing an expanding market for portable power, several companies are pursuing independent research and development programs.
One of the military’s major battery suppliers, Saft, developed an “advanced lithium power source” with the military market in mind. It can take energy from DC power from a vehicle, a solar panel or AC power from a wall plug or a generator. “We funded ALPS out of our own pocket,” said Jim Hess, Saft’s director of defense sales.
Greater use of renewable energy should help troops lighten their load, he said in an interview. “Where there’s a base camp, it makes a lot of sense to capture every bit of resource from the area. … You cannot run the entire Army on solar. But you can reduce some fuel burn.” Unlike fuel cells, which create a logistics problem because the fuel the Army uses can contaminate them, “solar is the same everywhere,” Hess said. “So there are no compatibility issues.”
Another top supplier, EaglePicher Technologies LLC, is working on reducing the weight of the brick-size disposable batteries that soldiers use to power communication devices. The company has introduced a lithium-carbon monofluoride battery that was designed specifically for military radios. These batteries are “considered very stable compared to other lithium-based structures,” according to EaglePicher publicity materials.
It is estimated that the Army buys 200,000 custom-designed radio batteries per year at about $50 each. One problem with radio batteries is that there are no common standards, and most radios require unique batteries that are incompatible with others.
These logistics burdens could one day be eased if ongoing efforts to exploit solar power are successful, officials said.
“One program in particular that has contributed to lightening the load of the combat marine is the solar powered alternative energy solution, or SPAcES,” Kelley said at a recent congressional hearing. “On the individual marine, over a dozen batteries, in six different configurations are used at any given time,” Kelley said. “Centralizing power, standardizing that power, and reliably distributing that power has the potential to reduce the reliance upon multiple types of batteries that are currently used in systems and carried in significant quantities as spares, not to mention the environmental impact and waste disposal.”
In Afghanistan, Third Battalion, 5th Marines — which is using SPAcES — reported that troops are able to conduct patrols for two- to three-weeks with just a handful of batteries, said Kelley. “Typically, a platoon leaving the FOB [forward operating base] for that period would be required to carry a two- to three-week supply of batteries,” he said. “Due to the employment of SPAcES, that requirement has been reduced to two to three days.”
The Army, meanwhile, has fielded 100 backpack-size solar recharging kits, and expects to ship 700 more, officials said.
Known as REPPS, or rucksack enhanced portable power system, the 10-pound device can charge the most common military battery types in five to six hours of solar exposure, according to an Army data sheet. If higher-power devices need to be charged, multiple REPPS can be daisy-chained. The first shipment of REPPS was sent in July to the 173rd Airborne Brigade at Forward Operating Base Shank in Logar, Afghanistan.
Smaller solar chargers that soldiers use to power iPads and laptops come with a USB port, said Todd Burns, a sales executive at DynGlobal LLC, which supplies foldable solar panels to the U.S. military.
The $200 to $250 panels are widely sold commercially, Burns said. “You can charge your cell phone sitting on the beach and it’s just like plugging it into the wall.”
One reason why the military likes these systems is that they are easy to use. To get the maximum benefits of solar energy, users have to carefully pair chargers with either batteries or small diesel generators, said Burns. “They can run 24/7 on solar, but if they go several days without sunlight, they have a battery or diesel backup.”
Burns cautioned that not all batteries perform well with renewable energy. “It’s better if you have a renewable-specific battery,” he said. “They’ll last longer.”
Larger scale solar power systems also are being introduced. The Marine Corps is deploying a ground renewable expeditionary energy system (GREENS) that provides 300 watts of continuous power, making it a valid alternative to a small generator. Navy engineers built seven GREENS systems for India Company.
Marines so far like the system and are planning to buy 2,500 more over the next five years.
The Army’s counterpart to the 3/5 Marines is the 1st Battalion, 16th Infantry Regiment, of the 1st Infantry Division.
The unit deployed to Afghanistan in January with the latest green technology, although it has not made as many headlines as the 3/5 Marines, Vane noted. “The Army’s publicity on this hasn’t yet rivaled that of the Marine Corps’,” he said.
Vane’s special assistant who oversees energy programs, Army Col. Paul E. Roege, said the battalion spent six months last year at its home base in Fort Riley, Kan., testing a “networked energy system” that allowed a squad to charge numerous devices with multiple, interconnected energy sources. They will use the technology in Afghanistan through the end of the year, and will help the Army decide whether it is worth pursuing further.
“In a year or two, it would seem plausible that we can make some real progress,” Roege said in an interview. The use of solar power, particularly, should make huge strides as it becomes more mainstream. “People at home have solar-powered landscape lighting,” he noted. “It’s not that hard anymore.”