In crossfire version 2.4 you can now unlock 1 watt or 2 watts of power directly through the module Bay. I currently have a xt30 running off the 2s 18650 I use to power my frsky qx7-s that connects to the crossfire module for external power. It warns you when yo u select 2w that it may damage your TX. What I'm curious about is if anyone knows if the 5v Power of the qx7 can give enough to power the crossfire at full power? I don't think I need the full power but I use dynamic power just in case. Normally it never goes over 500mw out several miles.
Thanks

I know some people are running the big Crossfire this way.  I prefer to use the supplemental battery.  The main reason for this is, the Crossfire will use the supplemental battery at all output levels, 25mW-2W (as long as the supplemental battery voltage is above the TX battery voltage).  That leaves the TX battery for just TX operations.  And that equals longer flight times overall.

To answer your question directly, I'm not completely sure, but I'm betting that 5 volts is not enough to produce 2Ws output.  I would ask Raphael Pirker (Trappy) on his FaceBook page.  He's pretty good about getting back to people.  Check back in here if you find out one way or another so we all can learn.

Why don't you want to run the supplemental battery on yours?