This thesis presents the design and implementation of an electric tricycle and a buck charger. The electric tricycle uses 10-14 60Ah LiFePO4 cells for its battery pack and can accept pack voltages in the range of 28 48V. To achieve such a range, the electric tricycle has the capability of using two different motor controllers. These controllers are used to regulate the current supplied to a brushless DC hub motor that is placed directly in the hub of the rear wheel. A hub motor was selected since it does not require any extra form of coupling between the motor and vehicle. Speeds up to 16 mph were achieved with the electric tricycle and based on measurements and calculations, the tricycle could travel up to approximately 85 miles.
Once the tricycle has used up the energy available in the battery pack, the cells would need to be recharged. Based on the design of a switched-mode power supply, a battery pack charger was constructed. Since the cells have such a high capacity, the charger was designed to be capable of providing relatively high charge currents. Independent of cell chemistry, the charger was capable of providing the desired charge currents for battery packs up to 150V. Also, the charger could be unified with a battery management system (BMS) so that a more accurate method for charging could be employed. Operating in the standalone mode or the unified BMS mode, the battery pack charger was able to fully charge a 10 cell LiFePO4 battery pack with a BMS in under 6 hours and a deep cycle sealed lead-acid (SLA) battery in approximately 2 hours.