('UBEC' is a propriatery brand name, no information in the name. I prefer
LBEC, linear, and switching
SBEC, switching, gives more info.)
How many servos will you be using, what battery voltage?
Don't use more than two-three(?) servos in combination with linear LBEC on 4s or more.
The higher the power-pack voltage, the fewer servos a
non-switching = linear BEC can handle.
Switching 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.
In depth: