Battery was going out on my touch 3g and I have replaced 2 on Ipod video 30 g.
Bought new battery @ Amazon, but failed to include touch in the description (touch 3g). Bought right battery from Ifixit. Unfortunately I watched the videos on Utube to replace battery which did not explain that there are tabs to be released on the screen ( Ifixit diagrammed it well ) Bought new screen on Amazon. Looked at ifixit diagrams to remove lcd gently ( mine must have extra glue ) Bought new lcd and second screen at Ifixit. I am currently listening to my new Ipod touch 5. I'm not sure how soldering the battery on the 3g touch will go, but at least the pressure is off.
My advice is get the battery professionally replaced. I would have saved some money. If you do it yourself look at the material on Ifixit and when taking out the lcd make sure there is absolutely zero flex in the screen. After you pry up the end they say to start at, there is still glue on the sides. I need to start a show similar to renovation realities but for electronics repair.