Ironically, I'm having the same problem, but nobody from apple support has mentioned the iOS being a concern. After three calls with diagnostic checks, a hard reset, and screen shots to show that battery life was draining by 50% in an hour, I was advised to have the battery replaced. With the phone out of warranty, I was given a 9 day window to do this, and had the option of sending my phone in and not having it for approx. 7 days, or driving to our closest G bar; 1.5 hours away. I opted for the drive, which frankly was a waste of time. They wanted to complete the exact same hard reset, and stated that because the battery was showing at 80ish% working through the diagnostic, that I could have it replaced, but with paying for it. Caught me off guard... absolutely... because it wasn't mentioned on the call with support. Furthermore I don't know why I had to have it done within 9 days, if I was going to be asked to pay for it. After much discussion with the store member, and reviewing options with the small chip at the top of the glass, I ended up leaving with my phone in it's same condition, but at 30% less battery life in the 30 mins I was there. By the time I made it to the truck, I had received the standard message one receives when the battery life drains to 20%. I'm having to walk around with a charging cord at all times, because it just won't stay charged. I'm just perplexed by the entire experience.