In a probably unrelated issue, my iPhone 5 used to show a higher battery percentage charged than actually existed. I chalked it up to iOS not being able to read the battery charge correctly.
I talked to an ATT representative about the issue one time, and he claimed that the batteries become unstable after 2-years. How convenient, huh?
I bought a new iPhone 6 two weeks ago and haven't gotten around to setting it up completely. It still burns through 10-15% of battery everyday despite 2-4 daily phone calls under 5 minutes each, having most features disabled, and minimum apps installed.
I am still going to fuck with iPhones though because they are the most secured. I use my phone mainly for checking emails and casual Internet browsing.