Airman 1st Class Christopher Mcgillis, 28th Operations Support Squadron aircrew flight equipment technician, tests the power of lithium batteries from an aircrew survival vest during a routine inspection at the 34th Bomb Squadron on Ellsworth Air Force Base, S.D., July 25, 2012. Each vest is equipped with two lithium batteries, one already in a radio and the other as a spare. Technicians inspect the batteries every 60 days to ensure they are operational and are properly charged. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)