up to 10 cell nimh. which is 12V, which will probly be slightly faster than a 3s lipo since it only makes 11.1V.lipoe or 10 cells, its balistic IMO. sure its not a feigao or neu or hv system, but for the price it is and the power it makes, i dont complain. its pretty damn amazing. it turns my badlands on my e-maxx into friggin saucers. tires baloon so much its crazy.