Serpent 960 going E powered. Need advice.

[Semi Pro]

well i can tell you from my serpent that a 1518 isn't going to fit with mechanical brakes, I'm pretty sure you are going to be limited to motors around 60mm long

personally i would run a pair of 6cell35c 2500mah packs, one per side with the 2250 of 2650kv motor

longer shaft will solve afew problems but i think your going to create side loading if the shaft pulleys get to far away from the bearings