Merry Christmas! And thanks for the details; never would have tracked those down. I'm completely new to working with electronics, so apologies for the follow-up questions; I expect they're obvious to those who have any kind of experience:
1) For the balance cable I imagine you need a 7-way plug...
Could you post a bit of detail about the plug-in ports (sorry one of the things I don't know is what they're actually called!) that you used for the power and balance cables and how you wired them up? I haven't seen anybody else with such a clean look on their charging setup.
Lots of...