ESP32: Tips to increase battery life
Power Management, Adafruit ESP32-S2 Feather
How to Power ESP32 with Battery
Electronics Low-Power design tips, by Bogdan Yanko
ESP32 Battery Life Tips
Engineering Proceedings, Free Full-Text
ESP32 Save Data Permanently using Preferences Library
ESP32 Thing Plus Hookup Guide - SparkFun Learn
Battery-Powered ESP32 RadioShuttle Network Protocol