so how long should the batteries last, since they only operate the servo (i assume) i thought they would last for at least a few hours, correct me if i a wrong. but in't the fuel the only thing that I should have to bring spare with me, or I should at least only need 1 spare set of batteries??? coz the fuel seems really cheap, but the batteries are dead expensive. I have a model rocket, but I barely use that because the motors are too expensive