when i was using android 7.0 battery backup shows around 24 hrs(not even 2 days as sony promised) on full charge but after update it went to 13 hrs on full charge..and drains way too quickly....i used pc companion to reinstall the software...in the first boot it showed close to 2 days ..but after first charge it dropped to 13 hrs again..is my battery damaged ??or some other prioblem.BTW i am using the charger provided in the box by sony(Fast charger)...please reply
