A BEC is a Battery Eliminator Circuit
Its a component built into many ESC's that provides power on the positive lead of the throttle servo meaning small planes don't need a receiver battery along with a flight battery, it sends a regulated voltage to the receiver.
The HV-80 doesn't include an integrated BEC so your choices are to purchase a separate BEC and run the radio/servos from the motor battery, or, given the size we are talking, just run the receiver from a conventional receiver battery.