On Tuesday, 13 December 2016 09:48:05 UTC, Chris Green wrote:
In relation to my 'mains doorbells' thread while searching I have come
across 'kinetic' doorbells. The sender/bell-push uses the energy
provided by the user pushing the button to provide power, so there is
no battery in the bell-push. The sounder is a conventional mains
powered device.
It sounds like exactly what I want but I'd like to know if they really
work well before buying one.

I think MK use this type of thing for their wireless light switches, so the technology is sound. In fact you could use one of those switches (if they come in momentary action) to run your desired mains powered bell.

Lucky Golden Hedgehog "Visitor Makes Happy Tinkle" doorbell may be a less successful implementation, of course.

Owain