Guy there is one application which u can use to check the capacity and "life" of ur battery, works as good as the ibackboot application for mac (if the name of the application is wrong, then apologize me, because i don t really remember it's name anymore) and u can see how many cycles ur battery did until now and etc!
The battery of my Iphone 5 after a half year seems to still be in a good shape, it s just that it is not anymore that linear.. For example i can have 1370 of battery capacity, but if i lose then 1% of battery it can jump from 1370 to 1348 for example. Reall behving strange
Or for example if i have 69%, the following 10% of battery which i use will last me for one hour, but the next 10% only for 30 minutes. Did sby experienced the same? Maybe i am having a little battery issue I don t know...