Just bought a one month old phone xperia mini pro. Person claims it is as new. Looks as new, everything works - but the battery is hard to understand - should it last for a day when i use the phone for a total of 2hours in that period? About 20 sms, not more than 30 mins talking on loud speaker, about 25 minutes of youtube video via wifi and leaving it for some hours with wifi on as well; playing around and arranging shortcuts - about 30 minutes, music player - 30 minutes. Brightness - 50%, screen turn off - 10 seconds. Maybe something else but probably not that much consuming. Any ideas? Is this a normal strength of the battery or is it bad? (i thought the battery would be enough for a 90 min video at least - but 25 minutes of video ate 7%-10% of it)