Thanks guys! Charged them up and wow... those hyperions are double the power than my true rc's. No puffing from the batteries Off topic question... I put some badlands on lpr sized rims and after the run, the wheels seemed to be much larger in diameter and thiner. When I press on the tire I can feel air inside... so I am assuming that air somehow got trapped in there. I did not drill holes in the rims for air, could this be the problem?