Udirc Smart USB Charger 4P SM Plug Type Charger for Rechrgeable Battery (apply to UDI007,UDI001,UDI002 Boat) suit for UDI001 ,UDI002 ,UDI007 RC boat Smart USB charger , 4P SM Plug uDI001 3.7v 600mah battery or UDI002 7.4v 1500mah battery both can use