I have had my iphone 4s since April and after the initial required charge I have always chargd it daily every morning for about 90 mins or until it shows 100% charged. But, since middle of last week it is losing charge very quicky coming down from 100% to zero and switching itself off after about 6 hours ?? To give it the best possible chance I have switched off Bluetooth and made sure all apps are off.
I booked an appointment at the Apple Genius bar and after telling me that I need to charge the phone for 6 hours daily regardless of the battery level indicator showing 100% they replaced the battery with a new one and sent me packing. Last night I charged it as advised for at least 6 hours and guess what from 100% to switching itself off due loss of charge took about 6 hours !!!
I will return to the "Genius" Bar on Thursday to try again.