I had a bad / old battery in my iPad.
I went pretty good until i was going to re assemble it, i managed to break the display, ending up with a garbled and broken display instead of a bad battery. My iPad is beyond repair now i think, unless i replace the display but then i have spent more money on parts than on a refurbished one =)
I got to take apart and then reassemble an iPad that was a pretty cool experience, i know know that you should not dabble with these kinds of devices. It's broken now don't think i will get another one either. Fun experience though =) The iPad was given to me so it's not a big loss to me.