Cell != Battery

Battery = MANY Cells

I am not correcting you just hate the headline.

If you made a battery with 666(667 if we round up) of these you could supply 2ma of power at 3v for 50 years!

I don’t have sizes available so assuming 2032 sized batteries… If you stacked them that would be over 2meters tall.

With further advancement these could be viable

A lot more than that. 2ma

Analog circuits are weird though

https://www.ti.com/lit/ds/symlink/ne555.pdf