Battery Life My battery running out after 2 hours. I have 4S iPhone what can I do?

You can replace it with an aftermarket battery. That takes opening the case and a bunch of fiddling around inside .. If you are good with tools and have a lot of patience then go for it .. look at ifixit.com or iphone4parts.com for the stuff needed .. Otherwise .. Get an external battery case like a mophie or find a local iphone repair place and pay them to do it for you..

Links:
iFixit The free repair manual iFixit iPhone4Parts Custom Aftermarket Parts for iPhone and iPad

you have a bad charger or the battery is used out....try to connect the phone to your computer and do a reset if you can.or an update for battery

My iPhone 5s 64GB battery life is not much better than my 4s 64GB battery life, but considering that the 5s is much much faster than my 4s I guess that's pretty impressive.

mine used to go dead quick try getting a new battrey if you can but that might not fix it.

Once you purchase the iphone,dont use it yet.Instead of using it right away,kindly charge your IPhone with the wall charger for 3 hrs.Please dont use the Iphone while charging.Kindly check always if the battery is full.Once its fully charged then that's the time that you can use the iPhone. Once fully charged, let the iPhone's battery fully drain.Please keep the iPhone off for 2 hours.Fully charge your iPhone and allow the battery to rest in the fully charged state for two hours. (You may use your iPhone during this time as long as the iPhone is plugged in).Repeat the third and fourth step a maximum of three times if you feel your battery indicator is inaccurate.

Here are some tips for your everyday charging for your IPhone:
#1 - Charge your iPhone throughout the day when available. Charge EVERY night, regardless of charge level. This will keep your battery active, which is healthy for the iPhone's battery.
#2 - Use a wall charger or car charger w/ rated output 5V 1A. Computer chargers might not charge when the computer is in standby mode.
#3 - You cannot overcharge your iPhone. You don't need to disconnect the iPhone from the charger after it's done charging. Once fully charged, the iPhone will run strictly off of AC power and will not damage the battery.
#4 - Every two months, make sure you fully charge and fully drain the battery, in one cycle. This calibrates your battery indicator. If you fail to do this, your indicator will become inaccurate. Calibrating your battery does not improve battery life.
#5 - If you ever need to store your iPhone for any reason, make sure your battery is stored @ roughly 50% and in a cool environment.
#6 - Always charge your iPhone out of its case (assuming you can easily remove the case). Charging your iPhone inside your case will make the iPhone hotter, which is bad for the battery.
#7 - Charge your iPhone in a cool location. Charging your iPhone in a cool environment has a tremendous impact on your battery's lifespan. The colder the location you use to charge, the more charging cycles you can complete without your battery deteriorating. Avoid charging in direct sunlight.
#8 - Use properly rated chargers. Using chargers that are not properly rated will have a huge impact on your battery's lifespan. Make sure your car charger has the same rating as the official Apple charger.
The official Apple wall charger is rated as follows:
Input: 100 240V ~ 50/60 Hz 1.0A
Output: 5V 1A
Thanks!

that's because your using GPS signal that is constantly resetting itself and it uses battery life to do so, GPS uses more energy than anything else the iphone will do. If your still within hardware warranty call Apple and they might help you with it

This is a really good article that will take you step by step through the settings that will best optimize your battery life. And if this doesn't help you should make an appointment at your local Apple store, they are always very helpful (at least in my experience).
http://www.apple.com/batteries/iphone.html About iPhone BatteriesLearn how to maximize the lifespan and battery life of your iPhone.