The Air Force Research Laboratory is developing lithium-ion batteries for low earth orbit (LEO) and geosynchronous earth orbit (GEO) spacecraft applications. As a part of this lithium-ion battery development effort, a testing program is underway to determine the viability of lithium-ion batteries for LEO/GEO applications. For LEO, lithium-ion battery cycle lifetimes of >60,000 cycles at 25% depth-of-discharge (DOD) are projected. For GEO, lifetimes of >14 years at 80% depth-of-discharge are projected. (C) 2003 Elsevier Science B.V. All rights reserved.