Battery powered pi NR projects?

Just curious if anyone uses a pi powered from an 18650 or a lipo battery?

And how do you handle the shutdown when the battery is running low?
Or just cold turkey down when battery is down?

I am thinking of an AD converter to check battery voltage and control it that way.
Then when the battery is running low sending i shutdown

One day I found this: https://www.amazon.de/Innovateking-EU-Stromversorgung-Unterbrechungsfreie-Batterieladegerät-Erweiterungsplatine/dp/B08NJSR77R

I don't have it. But it looks like you can monitor it with python. So it should work with NR as well

https://www.raspberrypi.org/forums/viewtopic.php?t=260058

haha that last post is funny :wink:
it is all most build in.
so with an AD converter it should be piece of cake.
Thanks!