WONDOM Lithium Polymer 503040 Flat Battery 3.7V 600mAh 5 x 30 x 42mm with Plug
Amazon.com: Fisca Rechargeable 3.7V 600mAh Lithium Ion Spare Battery with USB Charger, SM 2P Connector for RC Robot and Robotic Dog : Toys & Games
Amazon.com: Blomiky 2 Pack 3.7V 600mAh Lithium Rechargeable Battery and 2 USB Charger Cable Compatible with Fisca Remote Control Robot Dog K9 Battery 2 : Toys & Games
3.7V 600mAh Lipo Rechargeable Battery Li ion Cells 503040 with JST ZH 1.5mm 3Pin