This paper presents the final design and validation tests of the MobyPost vehicle’s drivetrain which will be installed in a Fuel Cell Hybrid Electrical Vehicle (FCHEV) used in postal delivery application. Distinctive feature of this application is the numerous successive start/stops phases occurring during a short distance mission (i.e. <50km). After giving the main steps of the methodology used to design and size the main components of the powertrain, a focus is done on the validation process including the implemented control strategy and the related experimental tests. Originality of this work lies in the management strategy which takes into account the State-oh-Health (SoH) of each component present in the powertrain. The concerned components are the fuel cell system, the DC-DC boost converter, the traction battery, and finally the complete powertrain. The degraded mode ensures vehicle’s continuity of service when one or several components are faulty or operating below their nominal performances. Experimental results are drawn using realistic power scenarios computed from field measured driving cycles, they validate the sizing method, the design, the components selection and the power split control strategy presented in this paper.