11.1v 20c will be fine, search up predator ETU problem for best 11.1v from component shop. Just don't change motor to beefy one and 11.1v 20c will be fine
15c is pussy, 20c is quite docile tbh, 25c I ran in my FFR but it said whoaaaa when I shoved in a beefy motor the lame wires n module can't take it captain she's gonna blow. And she did, ripped the poxy ETU out in the end