My iphone 4s' battery is dropping quickly?

I've had my phone for over a year (I believe), and today all of a sudden my battery is dropping quickly. It will drop 20% all of a sudden without me doing anything. Nothing is open and all that junk so I know it's not that- any help?

Get a app like battery doctor it will tell you what's draining you battery

You can buy a new battery from apple for like $100

Buy a new battery or carry a portable one if needed. My wi-fi, 3G and location services are all turned on, but my battery does not drop too quickly.

  • Why does my iPhone battery die so quickly? I had my iPhone for about a year and a half, and recently I've noticed that the battery is draining incredibly fast. I've always had it on 3g internet/Wi-Fi and the battery never died this fast so I don't know what the exact problem is. I charged it to 100% yesterday and I only used it for maybe about 10 minutes and left it untouched for the rest of the night. Today when I woke up the phone was dead. I haven't changed the settings or anything fyi.
  • Why does my iPhone 4s' battery die so quickly? I'll have it fully charged when I wake up at 8, then it's basically almost dead around 1 in the afternoon. It use to not die this quickly. But now it's like crazy how fast it dies! I'm on Twitter a lot and I text a lot. But I use to always do that too, and it never died as quickly as it does now. Any tips to help save battery?
  • Why does my iPhone 4S battery die so quickly? - 2 I have an iPhone 4S with the latest update. I turned off location and system services and everything that could possibly be draining the battery, but it still dies fast. According to the usage tab, I have only had my phone charged for 6 hours and it's already at 30% (with a lot of use though). Why does my phone die so quickly?
  • Why does my iPhone 4S battery die so quickly? - 1 Everyday I turn off all the running apps and shut down my phone which is at 100% and then when I get home from school it's at 60% without me doing anything. My friend Hannah's did the same thing and her friend did something to it and now it loses only like 4% in 6 hours while playing on it all day but i don't know what she did. Do you know what she might of done or how you can fix this?