Electrons to the Lowest Echelon

The Army and USMC Get Power to Dismounted Troops

By George Jagels

Over the past ten years, American warfighters have become increasingly technologically advanced. More and more soldiers and Marines carry GPS, smartphones, networked radios, nightvision systems, and laptops. These devices give Americans an edge on the battlefield few can match; from long-distances to the darkest night, U.S. personnel talk to and see each other remarkably well. Through this interconnectedness and awareness, the dismounted squad, which the Army has been focusing on beefing up, might be able to achieve a major goal: supremacy over adversaries in the same way U.S. armor and air branches face no peer competitors.

This equipment, however, does not come “free.” With more power, so to speak, comes more responsibility—much of which literally ends up on the backs of soldiers and Marines. Though their capabilities are improved, the overall weight carried by warfighters changed little during the last decade (the soldier humps about 16 pounds of batteries, according to the Army). As a result, the DoD must strive for a near perfect balance: lower weight and greater capability.

The DoD is trying to break the cycle of adding more batteries for more devices. (Army)

The DoD is trying to break the cycle of adding more batteries for more devices. (Army)

The Path Forward

As Project Lead for Soldier Power at Program Executive Office (PEO) Soldier, Steve Mapes is one of those tasked with making the ideal a reality. “Technology has provided unprecedented situational awareness and capability in the hands of the small-unit leader. And with that technology comes the challenge of sustaining and supporting these devices,” he told me in a phone interview. To date, the Army’s Research, Development, and Engineering Command (RDECOM) has pushed a strategy to advance battery chemistry as a way of providing more power, but this path has limits. “In and of itself, advances in battery chemistry have not and will not keep pace with the power demand of the individual dismounted warfighter,” Mapes contended.

The USMC, which collaborates with PEO Soldier in this area, echoes these sentiments. “The Marine Corps realizes that the greatest opportunity to increase operational reach and combat effectiveness is to significantly reduce sustainment with significant improvements to efficiency,” said Major Sean Sadlier, the Technology and Requirements Analyst in the Expeditionary Energy Office.

Take the ever essential radio, for example. Much ink, including in our magazines, has been devoted to the semi-annual Network Integration Evaluations taking place in New Mexico and Texas. Networked radios feature heavily in these training sessions, and they require large amounts of energy. Moreover, Mapes noted, “Because we are equipping more and more of our small-unit leaders with radios of varying types, they are going to need batteries of varying types, and more of them.” Proliferating batteries is the problem, not the solution.

The Army’s goal is to make its squads autonomous for up to 72 hours. (The Marines aim for 96 hours.) That means no logistics support, no endless supply of heavy disposable batteries on a three-day patrol. “The reality is that there will always be some sort of storage device [i.e., battery] on the warfighter,” Mapes said. His remit is to simplify the numerous batteries soldiers wear. “The vision for the future is to leverage that single device to provide extended power so he doesn’t have to carry more than that single device.” A lofty goal, though an absolutely necessary one, given the electricity in use by small units.

So we arrive at the classic question in strategy: How do we match ends and means?

Beyond the Disposable Battery

In a way, the military predicted the power needs of its personnel: RDECOM began development of the conformal battery ten years ago. The command later transitioned it to PEO Soldier for testing and soldier feedback. The USMC, Navy, and Air Force have also partnered with the Army to evaluate the conformal battery’s performance. “The warfighter has informed us at every turn how to make improvements,” Mapes noted. The battery is now being fielded.

At about 2.5 pounds and ¾ inch thick, the conformal battery is anything but bulky. True to its name, it can flex and conform to the curvature of ballistic plates worn by troops. With 150 Wh of energy, the conformal battery can power numerous small devices for long periods of time. It can be recharged in the wall in as little as 2.5 hours, while a standard 60-watt solar blanket does the job in about six hours.

Modular Universal Battery Charger. (Army)

Modular Universal Battery Charger. (Army)

Conformal battery. (Army)

Conformal battery. (Army)

Charging the conformal battery and others at scale presented new issues. While the currently fielded Squad Power Manager (SPM) uses a small flex solar panel to gather energy, it was designed to service no more than a nine-man rifle squad or smaller fire team. The throughput of such a device is unable to handle the charging volume of an entire dismounted platoon. According to Mapes, “The debate was: Do you continue to field administrative garrison-style chargers for soldier radios and equipment, or do we design and field more practical solutions for charging that are specifically engineered for forward operations in the most challenging environments?” As noted above, with more electrical equipment entering service, the Army had to find a way to avoid an endless parade of new chargers.

To solve this problem, the Army developed the 300-watt Modular Universal Battery Charger, which is capable of recharging the conformal battery in three hours and weighs less than six pounds. It can simultaneously charge a mix of radio and conformal batteries using a solar blanket, wall outlet, or vehicle power. Designed to fit into the assault pack of a squad member, the system has proven useful enough to be integrated into vehicle platforms. Coupled with the SPM—a “very utilitarian” device that scavenges power from multiple sources (including disposable batteries) to ensure the most critical equipment is charged—soldiers have more power for the right devices than ever before.

The Marine Corps, meanwhile, is evaluating a prototype of a wearable solution that combines smart power management, high efficiency solar panels, and individual water purification. Both the Marine Corps and Army efforts work hand-in-hand to inform the similar requirements for the services. Called the Marine Austere Patrolling System (MAPS), the system maximizes energy efficiency and weight reduction: On a 96-hour patrol, Sadlier said, “MAPS has the potential to reduce the carried load of batteries and water from about 60 to 70 pounds down to about 13 pounds [mostly through water reduction].”

The individual water purification system provides a physical barrier from protozoa, bacteria, and viruses that allows the user to collect untreated water directly into the reservoir and purify as they drink—thereby reducing the frequency of logistical resupply of water.

For energy, MAPS uses three main elements: the conformal battery, the Vest Power Manager (VPM), and high efficiency solar panels. The VPM is equipped with power data logging, automatic device recognition, the Maximum Peak Power Tracking algorithm, and a user interface menu. Capable of interfacing with any load from 4 to 34 VDC, it automatically recognizes connected devices, and power levels are adjusted to their appropriate levels. “A user interface provides a state of charge indication that aids the individual with mission sustainability for power and energy,” Sadlier noted.

The third element, high-efficiency solar panels, come straight from the Naval Research Lab. These are triple junction solar panels “tuned to transduce visible and infrared portions of the solar spectrum to electrical energy,” Sadlier told DoD PEP. The nature of this special multi-junction panel improves the conversion rate of solar energy into electricity to over 25 percent (versus eight percent for common off-the-shelf panels). Small enough to wear at the moment, Sadlier said that, in the future, these solar panels and each of the MAPS components may be integrated into tactical vests and provide dismounted combatants with a wearable piece of energy sustainment technology.

Continually Looking Ahead

Army research is looking at proven alternative charging solutions such as fuel cells to provide boosts of power renewables cannot quite match. Further down the line, both the Army and Marines may work with kinetic energy harvesting, which extracts power from human movement. Another idea is smart textiles that will move and pass power and data through body armor fabric—thus eliminating the need for some cables and connectors—for powering the dismounted warfighter.

Regardless of drawdowns abroad, development of better squad-level power applications will continue. The Army and Marines have learned not only the importance of the power question but also how to develop a process to advance their ideas. To wit, the Marine Expeditionary Energy Office and PEO Soldier frequently examine how to work with research groups in their services and jointly further ideas. Whatever the future holds, energy technology isn’t likely to pass by the squad any time soon.

This article appeared in the Fall 2013 edition of DoD Power, Energy & Propulsion.