ESP8266 Battery Voltage Monitor Simple – Hilo90mhz
Can i power this 'nodemcu esp8266 v3' using 7.4v or 8v power source in its microusb. actually i have two li-ion battery(3.7v) so , i am going to connect this battery in
ESP8266 Wireless Dev System - Non-Battery Version from BurgessWorld Custom Electronics on Tindie
IoT Lithium Battery Monitoring system using ESP8266 & Arduino IoT Cloud