3s is not adequate for a 9xl. A 7xl will run on 3s. 8xl on 4s seems to be the motor of choice for most e-revo owners.

I'll be converting to lipo myself in the next couple months. I plan on getting the Hyperion EOS0610i and a couple True RC 4s packs and maybe a 5s or two for speed runs and vulgar displays of power.