Lithium Ion Battery - 3.7V 2000mAh : ID 2011 : $12.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Lithium Ion Polymer Battery - 3.7v 2500mAh : ID 328 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits
18650 Li-ion 5V 2200mAh Battery Pack - Himax
Lithium Ion Polymer Battery - 3.7V 290mAh | TinyCircuits.com
Amazon.com: HXJNLDC DC 3.7V 5000mAh 755590 li-ion Lithium Ion Polymer Battery Replacement for DIY 3.7-5V Electronic Product, Mobile Energy Storage Power Supply : Electronics