More Power, Less Battery

Written by Peter Buxbaum

 

Whether true or not, the story is a testament to the increasing reliance of individual warfighters on electrically powered devices. Small teams of deployed special operations and other ground units increasingly carry with them a range of devices—from radios and GPS units to night vision goggles, range finders and body armor cooling systems—that operate on electric power. That means the troops must carry their power sources with them, and this adds to the weight and bulkiness of their burdens.

For the most part, the U.S. military still relies on batteries, not unlike those common in everyday civilian life, to meet most of these portable and man-wearable power needs. In the case of non-rechargeable—“primary,” in industry parlance—batteries, warfighters must carry replacement batteries wherever they go. In the case of rechargeable batteries, they must tote the chargers around with them.

In some cases, power sources can make up 20 to 40 pounds of the loads carried around by warfighters. Part of the reason for this burden is that different devices use different kinds of batteries.

It comes as no surprise, then, that the military and its industrial contractors continually strive to achieve greater power density—packing more electricity into a smaller package— in the batteries they produce and procure. There have also been efforts to standardize battery-run devices around a limited number of power sources and to optimize their usage by making batteries smarter.

Industry is also working on innovations that would allow warfighters to have access to robust portable sources of power. These efforts include developing light, quiet, fuelpowered generators and harnessing solar energy. But these newer technologies have yet to achieve widespread adoption by the U.S. military.

“The power needs for warfighter equipment are huge,” said James Voulgarakis, a sales engineer at Bren-Tronics Inc., a developer of portable power equipment based in Commack, N.Y. “Unfortunately, lots of times this is one of the last things equipment manufacturers consider. Their goal is to design electronics to accomplish specific tasks.”

“Equipment like night vision goggles and radios are big power hogs,” added Paul Dev, president of D-STAR Engineering Corp., a research and development concern based in Shelton, Conn. “Radios typically use nonrechargeable batteries that cost $100 a pop. They provide a few hours of energy and then have to be thrown away. Rechargeable batteries don’t have to be thrown away, but they weigh twice as much.”

U.S. Special Operations Command has not generated any specific requirements for power sources and supplies, noted SOCOM spokesperson Captain Wes Ticer. Rather, power needs are tied to the specific requirements for any given specific piece of equipment.

“Power requirements are usually non-proprietary in that equipment must be able to be powered by either standard commercial batteries or have an adapter that allows it to be powered by military standard batteries,” Ticer said. “Since SOCOM requires standard military batteries or standard commercial batteries, the number of unique batteries is kept at a minimum.”

In most cases, SOCOM uses the primary batteries that have national stock numbers (NSNs), such as BA-5590/5390, BA-8180, and others that represent standard industry form factors. “When the equipment is a COTS [commercial off-theshelf] item, SOCOM uses the commercial standard battery,” said Ticer. “For most developmental items, SOCOM requires that the system operate with nonproprietary batteries, either standard military batteries or standard commercial batteries.”

The maneuverability of special forces means that battery weight is a big concern. “They should be looking for the highest energy density with the lowest possible weight,” said Ralph Wise, director of technology at Ultralife Corp., a developer of portable power sources headquartered in Newark, N.Y. “The vast majority of these applications can be satisfied with COTS batteries, thanks to new developments in battery chemistry.”

In fact, SOCOM examines a number of characteristics when considering COTS batteries, Ticer confirmed, among them: watt-hours per kilogram, safety, weight, voltage, peak current and shelf life. “For rechargeable batteries, SOCOM looks at the number of charge cycles, charge rates and leakage specifications,” he added.

Equipment manufacturers and battery makers are becoming more aware of the military’s desire to use certain battery models, according to Voulgarakis. The result is a greater degree of standardization across equipment types and battery models.

“Equipment manufacturers are making it easier to get standard batteries to fit their equipment,” he said. “That way warfighters don’t have to carry one battery for each product and that reduces the weight they are carrying.”

Battery manufacturers for their part are also standardizing on a limited number of form factors. For example, the so-called 90-style battery has gained acceptance for hundreds of applications used in the field. The BA-5590, a non-rechargeable battery designed for manpack radio systems, spawned a rechargeable version, the lithium ion BB-5590, which has now gained widespread acceptance in over 90 field applications, including the SINCGARS radio and portable robotics systems.

Some military applications require modification of COTS batteries. The military sometimes requires that COTS batteries be modified with special connectors in order to promote safety. “In the case of high-energy batteries, the military wants to make sure that no mistakes are made installing the battery,” said Glen Bowling, director and vice president of sales and marketing at Saft Specialty Battery Group. “Those batteries come with custom connectors so that a warfighter can’t put it in backwards or wrong.”

Analytics Systems, a developer and manufacturer of battery chargers, voltage converters, and AC inverters based in Surrey, British Columbia, adds ruggedization packages to the commercial batteries it produces for the marine industry in order to provide its military products with greater protection from vibration and electromagnetic interference.

“Different applications require different levels of protection,” said Bill Walker, the company’s vice president for sales and marketing. “These can be pretty specific, so we are always exchanging information with the user about how much protection is needed.” These requirements are then accommodated in the manufacturing process. Analytics has supplied the Army and Navy with its products, primarily power supplies and battery chargers, through prime contractors and U.S. distributors. It has also supplied voltage converters as well as inverters, which take the direct current of batteries and transform it to the alternating current required to operate equipment such as computers.

SOCOM is currently investigating power source advances through a Small Business Innovation Research project, Ticer noted. These investigations cover power sources that include new primary and rechargeable battery chemistries and fuel cells— which use fuels such as alcohol to generate electricity—as well as solar energy, power scavenging, and hybrid systems, which combine multiple devices. Walker expects that, within the next year, the U.S. military will start to place greater emphasis on inverters and on alternative products that harness the energy of the sun. “Inverters take a battery as a source of energy and turn it into alternating current so that it can be used in the field to run communications and computer systems,” he said.

Industry is already designing products that use solar energy to charge batteries and power inverters, Walker noted. Man-wearable and portable devices could provide between 2,000 and 10,000 watts and weigh from 1 1/2 to 45 pounds. “The Army would like to get them all to 1 1/2 pounds,” Walker quipped.

But the U.S. military is “not taking advantage of the solar option in many cases,” according to Ed Atchley, president of A and A Logistics, a provider of military products based in Richardson, Texas.

“There are many areas in which we are attempting to work with the military,” he said. “Many of the people we are dealing with are not aware of the uses of solar energy for remote power.”

A and A provides a solar energy system that affords backup power to water purification systems. These products are used to charge the system batteries, Atchley emphasized, and could be adapted to a variety of military applications, especially in places like Iraq, Afghanistan and Africa where sunshine is abundant. Portable solar systems could be used to “augment an existing power grid,” said Atchley, “to provide power during peak usage during the day.”

A and A has also developed solar charging systems that would obviate the need for warfighters to run their vehicles for electric power. Such a system would have multiple advantages, according to Atchley: it would eliminate engine noise, and it would reduce the adverse effects that long periods of idling have on vehicle engines. The Italian military has acquired such a product, he noted.

Not everyone agrees that solar provides the ultimate answer, however. For airborne systems such as UAVs that fly above the clouds, solar energy may provide a complete solution, said D-Star’s Dev. In fact, D-STAR Engineering has completed research in that area.

“But for ground applications,” he added, “you have cloud problems and rain problems” that interfere with the capture of the sun’s rays. “For ground applications, I personally believe that lightweight, heavy fuel battery chargers and energy sets are the answer.”

D-STAR was funded by the Office of Naval Research to develop very small energy sets and battery chargers of 250 watts that run on heavy fuel and which are five to 10 times lighter than the generator sets currently in the military’s inventory. The term heavy fuel encompasses a number of different products including low sulfur diesel and aviation kerosene, which are heavier and more stable than gasoline.

The company is now working on a second generation of these small gensets for the Marine Corps, also funded by ONR, which would provide one and two kilowatts of power as well as two- and 10-horsepower engines, which would power the sets. Unlike the first generation, which never moved to a production stage, this second generation product is now being evaluated for manufacturability. “The smallest genset currently used by the military produces two kilowatts, weighs 200 pounds, and makes 78 decibels of noise,” said Dev. “The two-kilowatt unit we are developing for the Marine Corps we are predicting to weigh 25 pounds and make 68 decibels of noise, which is approximately nine times quieter than the current model. The one-kilowatt unit is predicted to weigh 16 pounds.

“Instead of carrying around 40 pounds of batteries,” Dev added, “we would provide a 40-pound pack through which the warfighter could charge his own batteries and those of four to eight others who would share one 16-pound device.”

Dev asserted that he could get D-STAR’s first generation products into warfighter hands within a few months, if requested, and that the second generation products could be ready for deployment in one to three years.

For the near term, the U.S. military will probably continue to rely primarily on battery power. The military could save some money if it were to acquire more rechargeable batteries, according to Saft’s Bowling, and, in fact, it has moved in that direction. “But in times of war, they bring primary batteries with them,” he said. “After the war winds down, they are likely to switch to rechargeable batteries.

“Rechargeable battery technology is getting better,” he added. “With lithium ion batteries, you can store more energy in a box.” But it is unlikely the military will ever make a complete switch to rechargeable batteries. “As a warfighter moves these days, the charging system still presents a logistical problem,” said Bowling. One promising innovation combines batteries with fuel cells and augments them with a system that manages their consumption of electricity.

SFC Smart Fuel Cell, a company based in Brunnthal, Germany, and a supplier of fuel cell products for mobile power applications, recently launched its Jenny portable fuel cell system for defense applications. The Jenny fuel cell has been in operation in the field by several NATO defense organizations, including U.K., German and French forces, since the beginning of last year, and is currently in a demonstration program with Israeli forces.

In 2008, the Jenny portable fuel cell won third prize in the U.S. Department of Defense’s Wearable Power Competition, while SFC’s next generation prototype, the M-25 Portable Fuel Cell, won the $1 million first prize in that competition.

“The system has been in testing by the U.S. Air Force Special Operations Command for about two years,” said Peter Podesser, the company’s chief executive officer. The Jenny portable fuel cell is operated in combination with the SFC Power Manager, an intelligent power management device that ensures any electronic device can be supplied with electricity by the fuel cell or other available power sources. The SFC Power Manager automatically adapts current and voltage to ensure systems will operate reliably and for much longer periods than batteries alone would allow.

“This product is designed for a three-day mission for a dismounted unit on its own and fully autonomous in terms of power supply,” said Podesser.

The small size of the fuel cell and the high-energy density of the fuel methanol, along with the SFC Power Manager, reduce a soldier’s weight load by up to 80 percent compared to carrying conventional lithiumion batteries, according to Podesser. “The fuel cell produces close to zero emissions,” he added, “and is barely detectable in terms of noise generation and in terms of temperature signature. It has been proven to operate reliably even in challenging environments such as extreme temperatures and fully submerged under water.”

The key feature of the system is the hybridization of battery and fuel cell power, according to Podesser. “The work load is being shared between the battery for peak power and fuel cell for long-term energy supply,” he added. “Users don’t have to change their existing infrastructure but can reduce the number of batteries being used.”

Podesser expects the U.S. military’s acquisitions professionals to see the advantage of this type of product in its lower costs and its simplification of logistics processes. “This could drive a major revolution in logistics costs,” he said, “by reducing the overall amount being spent for batteries and by eliminating dedicated batteries for different systems. Some of the batteries now being acquired can be replaced by one rechargeable and one refuelable energy source at a fraction of the weight and cost.”

Ultralife Corp.’s Ralph Wise sees smart circuit technology as the future of managing mobile electronic power sources. “These systems are able to interrogate the battery and meter energy out of the battery in every optimal way to provide much longer battery capacity,” he said. “It can also get data out of the battery to determine how many cycles it has seen and how many times it has been exposed to high temperatures. The system can use this information to evaluate the battery’s performance and to determine charging options.”

In all, smart circuitry systems can store up to 50 data elements and manipulate them to optimize battery use and life. They can also increase the capacity of existing batteries. Ultralife is currently working on a system that will effectively increase battery energy by 10 percent to 15 percent within a two- to three-year time frame, according to Wise.

The Protonex SPM and BPM power manager families provide intelligent battery management, conversion, and charging—vastly reducing the number and variety of batteries carried by the warfighter. The SPM-611 and SPM-612 are designed to be soldier worn or carried, and can operate virtually any portable military or commercial device, from any standard military battery. For example, the SPM permits a warfighter to simultaneously power an MBITR, a Toughbook, and a PRC- 119, while charging his PDA or cell phone, off one or two BB-2590 or Li-145 Land Warrior rechargeable batteries.

The handheld SPM, which weighs less than one pound, also doubles as a solar power converter and intelligent battery charger. It can charge BB-2590, Li-80, Li-145, BB-2557, and similar batteries from solar, vehicle, or garrison power. Each power manager can charge from one to four batteries, and will automatically adjust the charge rate based on the energy source available.

For higher-power applications, such as those involving satellite radios and laser designators, the BPM power manager provides similar functionality—powering multiple devices from a single battery. The somewhat larger BPM (about 1.5 pounds) has been fielded in both Afghanistan and Iraq in conjunction with both fuel cell and solar power sources.

Smarter battery systems will eventually be able to supply large levels of electric power in smaller and lighter packages, he added. In addition to reducing the cost and weight of the energy used to power current equipment, these systems will provide enough power in the near future to support portable tactical network and communications operations in far forward positions. ♦

Back to Top