The fuel cell is used to convert the chemical energy contained in fuels into electrical energy. In order for this electrical energy to be used to drive and operate electrical systems, the fuel cell output current must first be modulated. However, the overall power electronics of a fuel cell system are very extensive and complex, since different components have different requirements, and the current must be used as efficiently as possible. Research and development is therefore concerned both with powertrain components and the necessary buffer battery, as well as with the power electronics components, such as DC/DC converters, which are needed to match the voltage level between the respective high-voltage/low-voltage systems. For highest efficiencies, it is also necessary to further develop the energy management system, control units and the software used.