Watson Lithium-Ion Battery Pack (3.7V, 1800mAh) for HD B-1801
Amazon.com: EEMB 3.7V Lithium ion Polymer Battery 2000mAh 103454 Lipo Battery Rechargeable Lithium Polymer ion Battery with JST Connector Make Sure Device Polarity Matches with Battery Before Purchase!!! : Health & Household
Lithium Ion Polymer Battery - 3.7v 500mAh : ID 1578 : $7.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: 3.7V 1800mAh 804050 Lipo Battery Rechargeable Lithium Polymer ion Battery Pack with JST Connector : Health & Household