I own three iPhones currently, 4, 5 and 6. My iPhone 6 is my current telephony device, but I like to keep my old ones around as spare iOS devices for games, apps, FB, e-mail and web. My iPhone 4 still runs iOS 6.1.3 and battery life is excellent. It is the 5 that is the problem. Much like the 4, I'm now using it as spare iPod. It works just fine except for battery life. It ran beautifully under iOS 7, but when I upgraded to 8 that's when the battery life went in the toilet. I can literally watch the battery bleed 10-20% over a few minutes usage. I don't recall seeing any specific threads about iOS 8 and battery issues specific to the iPhone 5. Is the battery life/iOS upgrade likely just coincidental and do I probably just need a new battery? Note that I've done pretty much all the things I can find for turning down battery hogging functions to no avail. I also assume that there is no way to reinstall iOS 7 at this point.