This is from the specs page of the link the OP provided. Note the fourth line: BEC Mode: Linear and the fifth line: BEC Output: 5V/2A.

This means that the BEC output is 5 volts at 2 amps. This is to power and operate the RX and servos.


Model #: Volcano-12 (07E01)
Cont. Current: 12A
Burst Current (>10s): 15A
BEC Mode: Linear
BEC Output: 5V/2A
Li-ion/Li-poly: 2-4
Ni-MH/Ni-Cd: 5-12
Prgrammable: Yes
Weight: 13g
Size: 34*24*10