Amazon.com: Blomiky 2 Pack 7.4V 1100mAh 8.51Wh Li-ion Rechargeable Battery with SM-2P Plug and 2 Charger Cable fit for H101 H103 RC Boat RC Car Vehicles Toy Force Battery 2 : Toys
R/C Car 7.4V 3000mAh 15C Li-ion Power battery pack - Tamiya Plug [7.4V 3.0Ah Car Battery bigTamiya] - $19.80 : Lithium Rechargeable Batteries, Battery BMS, Pack Assembling
Amazon.com: 7.4V 1500mAh Li-ion Battery with SM-4P Plug for Huanqi 961 962 RC Boat UDI902 UDI002 RC Boat 2 Pack with USB Charger : Toys & Games
VOLANTEXRC RC Boat Spare Parts: 7.4V-380mAh-LiIon Battery for RC Boat
Lithium Ion Polymer Battery - 3.7V 350mAh : ID 2750 : $6.95 : Adafruit Industries, Unique & fun DIY electronics and kits