Adafruit Universal USB / DC / Solar Lithium Ion/Polymer charger [bq24074] : ID 4755 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits
18650 - 3.7v Battery Charger | How To Charge 18650 Li-Ion Battery | 5v To 4.2v Converter | 2n6292 - YouTube
3.7 Volt Lithium Ion / Lithium Polymer Battery Pack Smart Charger | eBay