I've been doing a little research into the 4700mah packs and they weigh a TON, one of the guys I trust at the field said I would get a lot more out of the motor with a 4700 pack. The motor is pulling 45amps at WOT but the plane flys fine at a little more than 1/2 throttle. The HET 2W motor is not rated for a 4s pack I'm told.