this is the part that scares me the most reinstalling this battery into the airpods removing this was hard enough and it doesn't get any easier I was having a little bit of difficulty installing the battery but it turns out there's actually a difference between the left one and the right one so we matched up which one the left one is and it's this battery so we're going to go ahead and install this one the right one just has the positive terminal more to the right and the left one has it more to the left we'll position the battery again that is so much easier I was really struggling before now we're going to apply some flux to both ends everything's so tiny this is very difficult only going to apply a little bit of flux I don't want too much cuz it's going to make a mess we'll be using some soldering paste just to make my life a little bit easier this stuff has a lower melting point than normal solder and I'm going to do the bottom first because that's the harder one that's a crazy looking solder joint but to be honest I don't care as long as it works I'll fix it up a little bit there we go we have the battery connected that's crazy