I am on my 3rd iPhone 4s. I initially thought my issue was a battery issue but now I am beginning to wonder... The phone will charge to 100% but it won't drain properly (it stays at 100% for a day or so even though it is being used and then the percentage will slowly start to fall) once the percentage does start going down it shuts itself off at anywhere from 50% - 70% so I never really know when to charge it or how long I can use it before it randomly shuts down. Once it does power itself off when I plug it into the charger, the battery shows red like it is totally drained and then after a few seconds it pops back up to the percentage number it was at when it shut down so I am not sure where I am at on the battery. This has happened to all three of the phones that I have gotten. It HAS to be something on my end for every phone to do the same thing but I am not sure what I am doing.... Any suggestions?