My wife had the battery in her iPhone 5 replaced, under the extended battery replacement warranty (https://www.apple.com/support/iphone5-battery/), back in September. Now, seven months later, her battery is acting up again - battery strength dropping in large increments, without an apparent reason. There has been no change in her usage pattern, in terms of apps used, location where phone is used, etc. We've tried the usual suggestions, such as letting the battery go dead, then doing a full recharge, to re-calibrate the charge meter. Nothing seems to help. Looking at the Apple site, it appears that the warranty on the new battery is only 90 days. Is that correct? Does anyone have any other suggestions, or experience with this issue?