ok i should give my 2 cents on this battery thing

it is recommended for LIion batteries to be fully discharged at least once a month - depending on usage- to maintain its health ..... but inevitably it will die or at least gives u a lot less time.... to i recommend buying a new 1 after 12 months of using the phone ..... which will not be that expensive if u buy it once a year. .... but make sure its official Sony or any other top brands ,,, i know a lot of cheap brands that offer shitty batteries thats gonna mess up ur phone

cheers, pauleece