If the air is too dry, the membrane in the fuel cell stack dries out. This can reduce the mechanical strength of the membrane, which is responsible for proton transport. The reaction product water can be transferred from the exhaust air, the humid side, to the supply air, the dry side of the fuel cells, via a humidifier.

However, if the humidity of the air is too high, it can condense into water droplets. These can block the fine structures of the gas diffusion layer or the microporous layer. Water droplets that strike the turbine side of the electric compressor also have a negative effect on the durability of the fuel cells. For this reason, additional water separators are used.

Acoustics in fuel cells is an interesting topic, as we are not dealing with mechanical components such as in a combustion engine. In fact, disturbing noises can occur in the electric compressor or as flow noises in the pipes. Appropriate resonators attenuate the undesirable noise.

The fuel cell stack itself (theoretically) requires no servicing and is designed as an assembly for a high number of operating hours. However, the filter elements must be replaced at regular intervals. The granulate in the ion exchanger, which ensures that the conductivity of the coolant is in the correct range, is also system-specific. This must also be changed at defined intervals. The same applies to the cathode air filter. It must also be changed regularly. Then there is the cooling circuit. Other service-relevant components are located here: the ion exchanger filter and the coolant particle filter. This means that car and truck workshops should not run out of work, even when servicing vehicles with fuel cells.