Since the second pack worked well there is nothing wrong with the ESC.

So on which charger did you charge the second pack?

Use the same charger on the first pack.

Also the included battery may be out of balance.

You may need to cycle it a few times as well before it starts puttting out the rated power.

Some of the included packs have been laying around for a while.

I normally cycle the LiPos on a computer controlled charger a few time and check them for capacity before flying.

That is why a CC charger is a good investment. You'll know right away if there is a problem with a battery.

LiPo's are fairly sensitive, and must have a certain charge before shipment. They must then be recharged before they run too low.

-

Re: Vibrating

Do you have it perfectly centered?

Balancing a small fan can be unnerving as it is difficult to find the heavy or light side.

I sometimes put a marking pen lightly against the turning hub.

The side that gets the most mark is the "heavier" side, so I add weight to the other side.

But getting it centered is critical.

If you got the fan up, did you check the retainer as well?

Try spinning the motor with the retainer on it w/o the fan.

Run it up briefly.

It should be fairly smooth if the retainer is not unbalanced. Also check for lateral play on the motor.