Amazon.com: HXJNLDC DC 3.7V 3000mAh 103665 Rechargeable Lithium Polymer Replacement Battery for DIY 3.7-5V Electronic Product, Mobile Energy Storage Power Supply : Electronics
KP-18650-2200mAh Li-Ion battery 3.6V - 3.7V with 2200mAh | akkuteile.de
Lithium Ion Polymer Battery - 3.7v 100mAh : ID 1570 : $5.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: 4 Pcs ICR 10440 Rechargeable Lithium Ion Battery,3.7v Batteries 350mAh (0.39 * 1.73 inch, Shorter Than AAA Size) : Health & Household