I bought a non working canister light the batteries where trash and after taking the lightheaded the smell of burnt plastic it also was trash. So I decided 4 x 18650's and 3 XML reflector modules where the way to go but as I have zero experience with this type of modding I need to know I need a driver ? Also do I need a heat sink ? Or because I am using it in the water does mean I don't need to worry about heat?