E Z Peaces wrote:

I've tried battery-powered wireless door chimes. I used AA alkalines,
which have a much longer shelf life than conventional carbon-zinc. The
problem was the current draw of the receivers. A set of
batteries would last only a few months, and a lot of visitors might
leave frustrated before I realized my chime was out of service.

How about a wired chime using a lithium battery? The battery could
outlast a transformer and be cheaper to replace.

How about a brass door-knocker which needs no electricity from any source?