3.7v 400mah 582728 Lithium Polymer Lipo Rechargeable Battery Li Ion Cells For Mp3 Smart Watch Pad Dvd E-book Bluetooth Headset - Rechargeable Batteries - AliExpress
Lipo Battery 300mah, 3.7V, 602030 - RobotShop
Lithium Ion Polymer Battery Ideal For Feathers - 3.7V 400mAh : ID 3898 : $6.95 : Adafruit Industries, Unique & fun DIY electronics and kits