Adafruit Micro Lipo - USB LiIon/LiPoly Charger - Newegg.com
Adafruit Universal USB / DC / Solar Lithium Ion/Polymer charger [bq24074] : ID 4755 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits
LiPo Solar Powered Sensor Kit | Power Management IoT Module Arduino – RAKwireless Store