EnOcean is a mostly battery-free radio standard and therefore it is also maintenance-free. The technology was developed in 2001 and became an international standard by the EnOcean Alliance founded in 2008. Meanwhile there are various methods of energy harvesting to work without batteries. The radio protocols have been optimized so that only short data flow and energy is required for communication. From time to time, rechargeable batteries are also used to bypass energy bottlenecks. Of course, Low Energy has its physical limits when it comes to the range of these short radio signals. Wherever possible, I use the battery-free, maintenance-free devices for integration. As can already be seen, there are some special features to consider.