Battery life becomes an issue every time Apple releases a new version of iOS or a new iPhone. If your iPhone, iPod touch, or iPad on iOS 6 suddenly losing charge far too fast, or if your new iPhone 5 is draining before your eyes.
So you can try this things:
First: Are you using your device alot?
First thing make sure that you aren't using your iPhone, iPod touch, or iPad more than you used to. Because when you have new features like Flyover or turn-by-turn navigation to play with, or when you have a brand new iPhone you just can't put down, your battery might be draining because you're using it a lot more. With iOS 6 there are more notifications, location features, and other battery consuming features than ever before, and the iPhone 5 has a bigger screen and an LTE radio to really put the drain on.
So put your device down for a minute make sure you're not the battery drain cause, because that's the easier thing to fix before you do anything drastic.
Second: Check if there is a problem with the OS or the device?
If your battery life is consistently short and you're basically just watching the indicator drain down before your eyes, here are some things to try, in order of how easy they are to do.
Try to restart/reset your device, it could be a rogue process or something else doing what it shouldn't be doing, and a restart can often fix that.There (Here's how to reboot)(http://www.imore.com/2010/12/17/beginner-tip-power-reset-ios-device-hit-problem/))
Power cycle monthly, and certainly if you're having problems, you should completely drain your device's battery, drain it until it shuts down on its own and then charge it back up to full.
Reset the your device again. The only thing that causes battery life problems with iOS devices occurs that are restored from backup and not set up as new devices. Whether it's cruft or corruption, a clean install as a new device, incredible pain in the butt though it may be,this is the best fix for any battery life issues.You will have to set up absolutely everything again, also you will lose all your saved data like game levels, but in most cases your battery life will be better than ever.
(Here's how)
Apple Store. Go to Apple Store because sometimes iPhone or iPad develops a real problem that only Apple can solve by either swapping it for another device or otherwise figuring out a fix.
Third: Are you plugging your device in?
If you're using your iPhone, iPod touch, or iPad a lot, plug it in to recharge whenever you can. At home, at work, in the car, there are plenty of opportunities to top up your battery.
Fourth: Did you turned off things you aren't using?
Anything running on your device uses up the battery. So if you've tried everything else and it turns out you're just using your device more than the battery will allow for the length of time you need to use it, you'll need to make some hard choices. You'll need to stop using some of the features you don't really need in order to keep using the ones you do. The more you turn off, the longer your batter will last.
-Turn off Siri's Raise to Speak. Go to Settings, General, Siri. Readers keep telling us this has helped them with battery life due to accelerometer issues.
-Turn off Location Services. Go to Settings, Privacy, Location Services, and turn off any app you really don't need tracking or using your location.
-Turn off Push Notifications. Likewise, go to Settings, Notifications, and turn off any app you don't care to be alerted about.
-Turn of Notification Center widgets. Stocks, and particularly weather in Notification Center seem to be causing our readers some battery grief. Since weather can be location-based now, the potential is there for more battery abuse.
-Kill power hungry apps. Double-click the Home Button to activate the multitasking dock, hold your finger on an app to enter "jiggly" mode, and kill any apps that might be running in the background, especially VoIP (like Skype), streaming audio (like Pandora), or navigation (like TomTom). (
Here's how)
Here are some old standbys as well:
Set Auto-Lock to 1 minute
Turn off any extra sounds, like keyboard clicks
Turn off the iPod EQ
Use headphones instead of the speaker if you have to listen to audio or music
Turn down the screen brightness
Turn off Bluetooth when not using it
Turn off Wi-Fi when not using it
Turn off LTE when not using it
Turn off cellular app and media downloads.
Set all email, calendar, and contacts accounts to "Fetch" (turn off Push)
Bonus tip: If you're really desperate, put your iPhone or iPad in Airplane Mode and save the radios for when you need them. If you're really desperate, you can also turn your device completely off until you need it (it will still use a tiny amount of power but far, far less than anything else).