Hi, I am still under my iPhone's warranty as I have previously extended it with AppleCare. I have tried many ways of saving the battery but it just seems to not be doing much. If I would like to have the battery replaced under AppleCare, how do I know if they will allow that? I know they mention about the 50% of expected performance - but how do they actually test it? And how do I know if I will be eligible before sending that in? Thanks!!