Adafruit Micro Lipo - USB LiIon/LiPoly charger [v2] : ID 1304 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits
4.2V 5200mAh Li-ion Rechargeable Battery Pack 18650 with DC Including charger & USB Ports for Cycling LED Bicyle Light Bike Lamp
4.2v 3a 5.5*2.1mm Ac Dc Power Supply Adapter Charger For 1series 4.2v 3.7v 3.6v 18650 Li-ion Li-po Battery Free Shipping - Chargers - AliExpress
USB to 4.2V 1A 5.5x2.5mm Smart Battery Charger for 3.7V Li-ion Lithium Battery | eBay
SuPower Li ion Li Po 1S 3.6V 3.7V 4.2V 3A Lithium Ion LiPolymer Wall Socket Battery Pack Charger auto stop AC DC Power Supply|battery pack charger|batteries battery chargerbattery charger - AliExpress