what battery to use?

[Gee]

I've ran TrueRc 2s 6400mah 15c lipos in my RCs and haven't had any issues with them. There are other rcm member that know more about this then me. I would guess 15c would be the very minimum to run so grab some 20 or higher if you can. 35000rpm use to be the number to shoot for on the motor. It will get you in the ballpark so if you take 35000rpm/2000kv it comes up with 17.5 volts. Same way if you wanted to know what motor to use and you are going to be using a 4s lipo you would take 35000/14.8= 2364kv for the motor.