Climate change and air pollution in large cities are creating new regulations that encourage the development of cleaner mobility. Although the value of fuel cells is proven, in addition to the use of battery-limited vehicles in battery life and charging times, the development of hydrogen vehicles is hampered by the lifespan and cost of fuel cells. For transport applications, with frequent stops and start-ups and large variations in power, 4000 hours of operation is a difficult limit to exceed. The ageing mechanisms of the battery are numerous and varied, chemical or mechanical, related to the assembly of the battery, its operation, or its use. In this context, StackPack aims to develop a PEM hydrogen fuel cell power unit for electric vehicles, improved properties in terms of service life (7000 hours), efficiency and cost. This project is led by the company SYMBIO in collaboration with the laboratories INL (CNRS) and AMPERE (UCBL). StackPack contributes directly to regional and European innovation and environmental objectives, works for the strategic positioning of Rhône-Alpine industrial and academic actors on the international scene and contributes to the revitalisation of the territory by forming a local hydrogen ecosystem, creating value and jobs.