The hardware design of the Power Management Control and Delivery (PMCD) is an initial step towards defining the control necessity for the aircraft. The finalized design allows for a visual representation of the switching for power management from the fuel cell and battery to the inverters. In addition to this, signals given during operation are used for failure handling for minor or critical errors. The process of sizing the components the PMCD was based on the maximum limits for voltage and current to range the full extent of the different flight modes of the aircraft. This was achieved for the HY4. With a functioning PMCD hardware for the HY4, testing on single components, as well as software development, could be started in order to confirm the functionality of the proposed aircraft. The key importance of PMCD hardware to be aware of is the dependency of all functions onto it.