The SeaKing V3 130A HV ESC is rated for 5-12S LiPo and ESC does not have a built in BEC Circuit. The receiver will need to have its own power source to provide a throttle signal to the ESC, power the servo, control the servo and ESC.
A BEC (Battery Elimination Circuit) is a voltage regulator that will take the battery voltage and cut it down to a specified voltage. Even though this ESC does not have this circuit it does have a "power (red)" wire on the throttle plug. This power wire on this ESC needs to see a voltage from 5-8.4V in order to have the ESC initialize and/or calibrate. This is specific to the SeaKing V3 130A HV ESC.
If you run an ESC that lists that it does not have a BEC Circuit, and the throttle plug has a red wire you will want to confirm that there is no power to that cable before plugging it in to your receiver and powering the receiver from an external source.