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
Dual 16340 Rechargeable Lithium Battery Shield Power Bank 5V GND Micro USB Charger Output Board For Arduino R3 One Module - AliExpress
Adafruit PowerBoost 500 Shield - Rechargeable 5V Power Shield : ID 2078 : $19.95 : Adafruit Industries, Unique & fun DIY electronics and kits
LiPo-Powered Arduino - Instructables
How to Power Arduino Nano with Battery: All Details to know
7.4V Two Step Lithium Battery Charger Circuit - CC and CV mode
The energyShield - Power for your Arduino Creativity by NightShade Electronics — Kickstarter
Sped-Up Video - Modding a 7.4v 3000mAh Lithium Battery (18650) for 2.1mm Arduino board power jack - YouTube
RCR123A 16340 Rechargeable Battery Power Shield for Arduino — PMD Way
Rechargeable Battery Pack for Arduino (with Pictures) - Instructables