I use a truerc 10c 4s2p 8000mAh lipo. I needed to use the supplied spacers to space out the TVP so I could get proper gear mesh and gear low enough. I use a neu 1515/1y/f and the lowest gearing I could fit without the motor hitting the battery was 52 spur, 18 pinion. This gives me about 38mph with the 3speed.
I was out bashing for a solid 35min. and only put back 4850mAh in to the battery. Also, the truerc 4s2p 8000mAh lipo is good for 3.425v/cell @ 124amp burst, they hold 3.525v/cell @ 100amp burst too. Not bad for $140....
Bye