Here's a basic wiring diagram for BPRC:
Here's one I drew for when I use the Deltang receiver and the BIK-U3 kit that consists of the on/off switch, charging jack, and fuses:
Deltang Rx65b receiver. Now I get them from Micro Radio Control in the UK and get the ones that are pre-wired. I believe the latest version is the Rx65c, I haven't bought one in a year or 2 (ruler in photo is in cm/mm):
RCS Australia BIK-U3 assy: