keep in mind he's running seven servos.....even with the bigger battery, that's quite a drain.......it also depends on the style of plane..... a trainer type plane stays straight and level much of the time and that puts minimul drain on the servos because your not moving the control surfaces much.........a sport plane or a 3d'er would be switching directions all the time and put more strain on the servos and most likely use larger, faster, more powerful servos.......best way to test it would be to just fly it and keep checking the voltage........for the sake of safety, i alway's check my batteries before i leave the house, at the field and after every flight.......even if you charge and check your batteries the night before and the day of, there's always the possibility you might bump the switch, accidently, when loading your vehicle or in transport they might rub together, so it's a good idea to check your batteries "preflight"......you don't want any surprises, like the pictures below.......JMHO, after 25+ years of flying.......thanx for listening, hope this helps????........(KOOLKRABBER47).........