Survival/military systems
In personnel recovery scenarios for military aircrew combat missions, the location of the survivor and the time associated with the extraction has a direct impact on recovery success. The combat survivor typically depends on aircraft beacons and survival radios to support identification and location by search and rescue teams. The energy storage systems (e.g., batteries, solar cells, fuel cells) have a direct impact on the capabilities of the survival radio and, consequently, the direction-finding and location methods deployed by search and rescue aircraft, depending on the battery or energy storage system selected, the associated packaging, and the monitoring and control of the energy storage. With the proliferation of electronic devices and digital equipment currently being made available to the military and special forces personnel, there now exists an opportunity to provide better solutions to both the power and energy characteristics/requirements for many military survival systems. Using the EMPF as an efficient resource for reducing risk, ManTech efforts are now underway to transition a number of these energy solutions from the research and development stage into prototype and production hardware.

A survival system is any piece of gear that aids the rescue or assists in deterring the capture of friendly forces. Most survival equipment is portable in nature, requiring independent and isolated power sources. The EMPF has recently reviewed survival radios (PRC-112), a Personnel Locating System (ARS-6), Beacon homing transmitters (TRN/30), GPS receivers, and Land Warrior cabling and interconnection schemes for potential improvements to their power and energy design capabilities. The power supplies, batteries, and energy-providing apparatus which activate these systems must be reliable and optimized to maximize war fighter effectiveness. The functional operational uptime of the equipment can be increased by tailoring the engineering design to match the requirements of the application.

Innovative electronics packaging methods and materials, modern manufacturing processes, and the ability to leverage resources (such as combining existing military solar panels and radios with commercial battery charging capability) are additional areas where the EMPF is benefiting the war fighter directly.

Conventional power and energy devices
Batteries remain among the most popular solutions for powering many of these portable electronic systems, and the increase in energy capacity with different battery chemistries is an ongoing effort with their manufacturers. Both single-use and rechargeable configurations of battery cells and battery packs are prevalent today. Much of the commercial research and development that has been undertaken for extending the battery life in laptop computers and additional features in cell phones is transferable to the upgraded sustainment redesigns of aging military equipment. To a lesser extent, solar cells, super-capacitors, fuel cells, and even mechanical energy stored in a wind-up spring to run a mini-generator, present other possibilities for powering survival radios, signal lights, beacons, and communication equipment.

Current technology and commercial off-the-shelf (COTS)
The current state-of-the-art in battery technology, and COTS devices related to their use in the survival environment, branches out in many directions. Lithium batteries are a logical choice for many of these systems due to the military environmental conditions (desert heat, arctic cold, jungle humidity), power capacity per unit volume, and their long shelf life. Lithium/Manganese Dioxide (Li/MnO2) in many military applications is replacing Lithium/Sulfur Dioxide (Li/SO2) as the battery chemistry of choice due to a number of incidents resulting in soldier injuries and the possibility of venting toxic sulfur dioxide gas. Increasing demand for higher energy and lighter battery technologies has also led to secondary lithium chemistries such as Lithium Ion (Li-ion). The trend and need for lighter-weight, more powerful batteries is unlikely to diminish with the evolution and improvement of communication and satellite equipment, coupled with the increase in communication devices driven by America’s war on terrorism. A number of new improved commercial off-the-shelf (COTS) devices are expected as a direct result of this investment and effort. See Table 1-1 below for a comparison of current battery technologies for rechargeable cells. Note that this table reflects typical data from various manufacturers’ data sheets, and should be used as a guideline only.

Another project successfully executed by the EMPF was a cable harness developed for the distribution of battery power throughout the local area network of the equipment, computers, and weapons carried by the U. S. Army’s Land Warrior digital soldier of the future. In addition, the EMPF has invested in the future of battery and fuel cell testing systems with the purchase of a model BT2000, 4-channel battery tester from Arbin Instruments of College Station, TX. This capability will assist in choosing the most appropriate battery solution for each individual application through the detailed acquisition of evaluation and test data for various power and energy cells under programmable, controlled charge and discharge rates. Reliability testing and verification of functionality by qualification of prototyped new designs are also conducted at the EMPF laboratories.

Future direction
Future direction for power and energy solutions points toward continuous improvements in battery technology, fuel cells, battery monitoring circuits, and the continuous lowering of the demand current and voltage required by equipment. One of the obvious ways to extend the equipment’s battery life is to lower the drain on it by using less power-hungry devices such as light emitting diodes (LEDs) in place of incandescent bulbs, CMOS circuits and logic chips, and the use of shut-down/sleep circuits when the equipment senses extended inactivity. This direction toward increased energy density and longer operational times will guide the EMPF in providing the optimum solutions required for future power sources and energy storage products.

Summary
Survival systems will exhibit improvements in both capability and capacity as a direct benefit from the technological advancements in the COTS power and energy storage devices, coupled with the applicable ongoing engineering efforts to implement them into both new and sustainment redesigns. Of paramount importance is the ability to respond rapidly with incorporation of new technology breakthroughs in electronic packaging, materials, component devices, manufacturing processes, and clever upgradeable redesigns. Improved performance, functions, and capability are often matched with significant cost reductions due to the economies of increased volume realized by combining commercial and military overlapping applications. The PRC-112 battery pack, redesigned to accommodate both standard and rechargeable AA cells, along with optional solar panel capability and a universal charging unit exemplifies the possibilities. EMPF-generated solutions to each unique application are best derived from a careful review of the latest power and energy technologies, followed by well-orchestrated development and implementation phases.