Eagle-Picher Energy Products (EPEP) has been manufacturing and testing large lithium ion cells (up to 100-Ah) for several years. Recently, work has focused on the testing of different chemistries at variable temperatures and designing and fabricating 100-Ah cylindrical cells. For the aircraft application the largest concern is irreversible capacity loss at elevated temperatures (70 degreesC). In contrast, for the aerospace application shelf-life and cycle life are critical. EPEP has found that the major contributor to the loss in low temperature performance due to high temperature testing, was the positive electrode. Eagle-Picher Energy Products (EP EP)will discuss recent results of variable temperature cycling and 100-Ah cell performance.