- Just attach a overloaded LiFePo 21700 with 4.35v. If ESP burns it’s a bad charge. If it works you got 1.65v to get down to 2.7v
- Store the sensor values & time to sleep in Globals before going to sleep. After next wakeup, if they did not change, do not turn on WiFi but go to sleep again for the time from Globals
- If the sensor values changed make your program on the ESP interact over MQ with an automation that tells him to sleep for X seconds while steady data over Wifi is not relevant or.
Have fun!