Insufficient Voltage to Receiver (Less than 5V which is minimum requirement for the Receiver)

Hello Everyone, I am working on a Fixed wing vehicle and i have incorporated Pixhawk there. The issue that is being faced is that the receiver is unable to get the required minimum voltage threshold i.e. 5V though i have 2S battery installed there.
Secondly, i gave the separate power to the receiver and it got powered but now Pixhawk is not being setup in QGround Control.
Can you please help me in this regard?

What receiver are you referring to? My pixhawk is powerd by a power module which supplies the 5V to pix, then I use a 3.3v satellite receiver which is plugged directly into the dsm port on the pix.
What is your 2s battery connected to?