I have recently brought an iPhone 4s of eBay, I spoke to the seller and he says the phone is in full working order and is selling it due to upgrade, when I got the iPhone it was in full working order and I put it on charge straight away, when it got to 100% I took it out and was just normally using it but I went to take a picture and it turned off saying I had no battery, I went to charge it and when it turned on it said straight away 30% battery, as time went on the battery drain turned to a higher percentage. Its at 100% and now I take it out for 5 minutes and the batteries already 'drained' even though there's 96% left, I looked online and many users are suffering from this problem and saying it is the new IOS update? No one has a solution and its really bugging me so if you could please help I would be so grateful!