Staff Sgt. Abraham Lagunas, an aircraft mechanic, uses a multi-meter to check the lead cell voltage on a C-17 Globemaster III nickel-cadmium battery while it's being recharged at March Air Reserve Base, Calif. on Sept. 3. Sergeant Lagunas is an air reserve technician from the 452nd Maintenance Squadron. (U.S. Air Force photo/Val Gempis)