I'm not even planning on using stock batteries. Gonna make my own packs up, better cells, better sealed, more Mah's. When we were testing the prototype tipping the battery 90 degrees caused the boat to loose it's self righting capabilites. Also, we always run the boats with PVC tape around the joint of the coloured dexk to the white hull. It should be interesting to see what comes of the speed differances!