AFRL Develops Remote Auxiliarary Power System Published Feb. 28, 2008 AFRL/SN WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- At the request of Air Force Special Operations Command's Special Tactics Squadron, AFRL engineers addressed an urgent operational need to solve the problem of recharging batteries in forward locations. The resulting remote auxiliary power system (RAPS) allows military forces to harvest power from any low-voltage (<600 V) transmission line in order to recharge chemical batteries in the field. Power harvesting is based on the premise that there are plenty of power lines available even in third-world countries. The availability of a system designed to tap into these power sources for military use translates into opportunities for nearly unlimited operational endurance. Lacking such a capability, Special Forces personnel have had no choice but to carry a fresh supply of new batteries, burdening them with added weight and further diminishing their rucksack's already limited storage capacity. As an alternative, solar cells work fine when there is sunlight, but they have poor overall efficiency. RAPS engineers were concerned about the dangers of making ground-level connections to high-voltage power lines but initially ignored the possibility of using lower-voltage lines, which use insulation that prevents a good electrical connection from ground level. Instead, engineers first concentrated on devising a safe method of transferring power from high-voltage power lines. However, after approximately 5 months of research, the engineering team decided to reexamine the feasibility of using low-voltage power lines. The RAPS method and its associated apparatus emerged as a direct result of this inspiration, solving not only the power-limitation problems of forces on foot in the field, but the significant safety issues as well.