The TC lead is supposed to be for a thermistor, where they maintain temperature and control for charging. My battery did not come with a wire but does have a pad. I went and soldered the yellow wire on it. Will see how it works. If not, then I have to pick up other types from ebay that has a 3rd wire soldered already so you know there's a thermistor already attached.

Very awesome guide. I swapped the battery and it's charging. Will see how well it works! One thing to note, batteries I got from online did not have the TC wire. I had to open up the tape wrap to solder the middle wire. There doesn't seem to be any issue so far. As for the padding you pull up to reveal the screws to open the headphone, it worked really well for me having a hook shape tool to grab the edge. The pad pulled up with the adhesive without any tears and I did not have to reapply any glue.