It was the last component to add to a working electrical system. We are assuming a vehicle that must be cranked, but that worked over a longer distance and longer time in which only coolant, engine oil and of course fuel was added. The generator saved the regular recharging of the battery with the help of the power grid, which had been common until then.

Every generator needs some cooling because of the conversion of kinetic energy in electrical of the heat dissipation corresponding losses occur. With the fan wheel, there is only one part on the three-phase alternator that determines its direction of rotation. This is marked on this with a small arrow.

As with the internal combustion engine, air and liquid cooling also happens in the generator. However, the former is limited to the vast majority of vehicles. The latter only occur, for example, in luxury class vehicles with greater performance requirements. There, the number of consumers has outgrown the assets of the air-cooled.

With liquid-cooled generators, heat dissipation can be better controlled. If there is more than one cooling circuit here, the generator can be precisely assigned to the one that best maintains its comfortable temperature.

Of course, the conversion of the chemical energy in the fuel into electrical energy is associated with significant losses. It is therefore comparatively expensive energy, because in addition to the losses due to the unfavorable efficiency, there are also the disadvantages due to the additional energy consumption of the combustion engine.

For a long time there have been neither V-belts nor V-ribbed belts as drives for the generator. The flat belt transmits the torque much more safely due to the larger friction surface. In addition, the tension of the belt is now automatically adjusted. V-belts could become noticeable by annoying screeching if not tightened regularly.

Modern combustion engines do not always run evenly, especially when the torque requirement is higher. This is particularly noticeable with supercharging and diesel injection. For this reason, the drive wheel has a freewheel at the top, which effectively dampens the different forces in the belt, at least during their withdrawal.