Adafruit Battery Packs Lithium Ion Battery 3.7v 2000mAh – kjdElectronics
Amazon.com: AKZYTUE 3.7V 654065 2000mAh Lipo Battery Rechargeable Lithium Polymer ion Battery Pack with PH2.0mm JST Connector : Health & Household
Lithium Ion Polymer Battery – 3.7v 2000mAh
Amazon.com: KBT RC Car Lithium Battery: 3.7V 2000mAh Rechargeable Li-ion Battery with SM -2P Plug & Charging Cable for RC Cars, Boat Spare Parts -2 Pack : Toys & Games