Goedendag ;-) *Better not use a linear L-BEC above 3-4s*. The higher the power-pack voltage, the fewer servos a *non-switching (= *linear L-BEC) can handle. *Switching* S-BEC's hardly have this restriction. The higher the battery voltage, the hotter a linear BEC will get, for a given current/load/servos. Or, in other words ... The higher the battery voltage, the lower the current a *linear* BEC can supply.
More info in this excellent video https://youtu.be/hgXP4__GjSo (*'UBEC'* is a propriatery brand name, misused/abused by Chinese manufacturers (surprise ),no information in the name. I prefer *LBEC*, linear, and switching *SBEC*, switching, gives more info.) Prettig weekend ;) en wees voorzichtig, Ron Nijmegen, Nederland