i'm currently having the same problem about battery life and after reading this whole thread i'm going to DIY my tab s battery tonight LOL
thanks to slackerz_86 and the_source for the tips, i'll update later.
I just finished giving surgery to my Tab S using only a guitar pick and here's the result:
1. I could not disconnect the terminal that connects the battery to the motherboard. How did you guys do it?
2. I peeled off the green plastic (warranty protection?) that covered the terminal. It would not go back in as it curled and lost its adhesive.
3. During the process I occasionally turned my tab s on. One thing that I noticed was that the plate next to the battery was VERY HOT when it was on even though I was not doing anything. I think this was the processor. It was processing something so intensely that made it turn hot. I might have to check the software instead.
4. The IR blaster area is actually glued to the back cover. I don't have a double adhesive tape or glue to stick them back together. Now on my tab s there's a noticable gap between the mainboard and the back cover. To me, this drops the appeal of Tab S greatly
5. Be careful with the IR blaster glass (the black one). It is just slotted into the side and can drop easily when you turn the tab sideways.
That's it for tonight. My problem still persists so I will try again next time with more preparations.