I just ordered the FW16 battery with the hope of creating an extension cable for it. In order to do this I need to have the male and female blade connectors. I found the parts from the git repository, but I do not see a place to order them without contacting the manufacturer directly and ordering who knows how many of them. 
Anyone have ideas? I’d love to hear them. Thank you!
Just curious, but what would the purpose of an extension cable for the battery be? I’m wondering because if you use an extension cable for the battery that extends outside the machine, it would likely interfere with the midplate and prevent you from closing the device. That would further prevent you from using it because you can’t attach the keyboard, trackpad, and spacers. Where do you plan on routing such a cable?
Framework does list some schematics on it’s github page, so you might be able to find what you want there. I haven’t checked it in depth so I’m not certain if they do post the battery connector information there. Hopefully this helps your search.
Didn’t see that you said you have already checked the github 
. You would probably have to call the manufacturer unless the port that Framework uses is really standard and can be easily found. You might be able to find a way to purchase it if you go online and search for the model number, but if Framework’s connector is custom then you’re probably out of luck.
This is just for a project. I don’t even own a 16.