1) I suggest you do a reformat, and see how it goes, could there
be a problem with your settings?
2)How long have you had it? if for more than 2 years, maybe the
battery life might have depleted. It is impossible for background
application to be running, unless jailbroken, as i believe iphone
does not support multitasking. To increase battery life, what you
can do is to dim the screen, and disconnect from any wifi
connections.
To the problem still remains, i would suggest you charge it to
the max, go to a neighbourhood handphone store and sell it quickly.
alternatively, you might want to have it repaired, but imo, its not
worth it.
