wireless doorbell - Xiaomi Planet
Xiaomi and the OPPLE brand bring a bell with self-powering. It does not need any batteries

Another new product from the Xiaomi workshop has appeared on the YouPin platform - the OPPLE doorbell. This is an interesting product because the outdoor unit (bell) does not need any batteries or an external power supply to operate. It is a so-called self-powered bell, manufactured by the company spoločnosť