UDI 2 Pieces Replacement battery for UDI RC UDI001 Venom Speed Boat 3.7V 600mAh Li-ion For UDI UDI001 RC Venom Speed Boat by UDI TOY, or other similar size compatiable Li-ion Battery with Charging Protection Enhance your racing experience by using replacement batteries. Each battery provides 7-9 minutes of racing time. Charging time is between 60-90 minutes. Durable in use,easy to install.