3v3 pin how to read voltage

[pato]

Hello
Due to some issue with battery plug i decided to use 3v3 pin for battery in my ab01 heltec’s.
Can anyone help me with code how to read battery voltage from that pin?

[UniquePete]

Maybe follow the link in this response:

ESP32 V3 Read Battery Voltage Questions

This is a link to a page I wrote about this recently, following all the discussion I’d read in various threads in this Forum. It includes a discussion of the circuitry you could use for a ‘MOSFET-switched’ voltage divider that would not drain the battery when not in use followed by descriptions of the similarly ‘MOSFET-switched’ battery measurement circuits on the various Heltec boards that I’ve used. The page also includes code that I have used on the relevant boards.

You can’t read the voltage from that pin directly so, if you’re going to bypass the internal battery management circuitry (by not using the JST1.25 battery connector), you’ll have to build something similar externally.