This project explores the design, manufacture, and testing of a DC-DC converter module for Monash Motorsport’s M21 electric race car. The module is designed to be able to provide 600W of power to the low voltage (LV) systems of the race car, with both 24V and 12V output rails. High voltage input is converted to an isolated, fixed ratio voltage using the Vicor BCM4414VGF4440C02, which is then converted to the required system voltages using custom DC-DC buck converter circuitry. The module is also designed to power the vehicle briefly using a lithium-ion battery pack, and then switch to DC-DC input once the high voltage (HV) battery of the vehicle has been enabled. This battery pack is then charged while the HV is in operation using custom charge circuitry.