For my senior project for the S.B. degree in Electrical Engineering, I constructed a rapid cell cycler for a high-power battery cell. The purpose of the cell cycler was to rapidly charge and discharge the battery over several thousand cycles to test the viability of using the cells for large-scale development of electric vehicles that support rapid charging. The analyzed cell was the HD 20 Amp-hr Prismatic Cell from A123 Systems.
Using a high-current source fixed at approximately 4V, the cycler charges the 20 amp-hour cell with 80A of current for a full-charge in 15 minutes. Since a constant-current supply was not available, a feedback loop was designed to keep the current roughly constant throughout the bulk of the charging process before leveling off to constant voltage.
The full project report detailing the research goals, design process, & relevant calculations is available here (6 MB PDF).