Buses, trams and trains operate around the clock in all weathers. They are exposed to wind and rain, heat and cold. Their use is calculated in decades or hundreds of thousands of kilometres. All these requirements far exceed those of most ordinary passenger cars. This difference also applies to battery-powered public transport vehicles. Accordingly, the study is preceded in the present chapter by a detailed analysis of the requirements for the operation of battery-powered multiple units and a comparison of the solution concepts of different manufacturers.