..As for the mods, I'm not comfortable discussing it because I did it in a way that works for me. I'm not 100% sure it will work for everyone..
Re: the mod, presumably the remote charging cable has a diode / something similar inside the connector's housing to prevent power flowing the 'wrong' way through the connector? Might PM you for more info ...
Thanks again
David
As for the mod, I'm comfortable enough to tell the truth about this "trick" which may "not 100% work for everyone")
OEM DJI RC charging cable consists of 12 pins, just desolder 4 outside pins (1,2 and 11,12) and you will be just fine perfectly charging your TB50 just by provide +26.1volt to the center 4 pins and - (negative) to pins 3,4 and 9,10.
yes it is that simple)