i am playing e-revo with mamba brushless, and cheap cheap 25c 4s lipo, with the option spur gear, the speed is ok ga and good enough in TKO. But i am still seeking and wannt try 6s lipo battery...In KWS i saw the IP 5000mah 11.1v lipo, not cheap leh.....
It may be better to buy 2x 2S lipo than 1x 4S lipo. Because once I bought the cheap EC 4S lipo... after only few minute of the first run, the battery cut and it turns out 1 cell in the 4S is dead already.
however, if you have space in your car, its better to run A123. either 4S, 5S or 6S A123!