What can you do with button cell batteries and nano?

How far can you get? Do not mind having to change batteries often, they are rather inexpensive and easy to carry around unlike standard A-AAA sizes. What matters is the size and form factor.

When I read the title I immediately thought "there must be thousands of things" :slight_smile:

Nick Gammon's power saving tutorial may be useful.

...R

Oops! Yeah, I had already hit the page and some others, but I did not find them satisfactory. In fact, over the whole literature corps, anyone s conclusion should be: there is no acceptable way to power these things AT ALL. So I should add here then: under no-sleep-optimization scenarios.

Can you rephrase the question into something sensible?