Small Footprint Arduino Nano With USB Charging Circuit (Li Ion or LIPO) That Can Turn Itself Off (soft Latch Power) : 8 Steps (with Pictures) - Instructables
Arduino Rechargeable Battery Options: How to Power an Arduino | Arrow.com
ESP8266 ESP32 Power Supply Rechargeable Dual 16340 Lithium Battery Charger Shield Module for Arduino R3 Board Power Bank|Instrument Parts & Accessories| - AliExpress
How can we use a LiPo battery with Arduino? - Quora
Adafruit PowerBoost 500 Shield - Rechargeable 5V Power Shield : ID 2078 : $19.95 : Adafruit Industries, Unique & fun DIY electronics and kits