These are some tips on how to improve the battery life of your iPhone, iPad, and iPod touch running iOS. Some of these tips apply to just iOS 7 but many can be applied to older versions of iOS as well.

Let us know how much your battery life improves in the comments!


Disable Background Application Refresh
iOS 7 brings the ability for apps to refresh their content when on Wi-Fi or cellular and even use location services. To preserve battery life, we recommend disabling Background App Refresh completely. Note that doing this will kill location services for your applications, so you wont be able to use Navigation in the background therefore you may want to fine-tune this setting based on your preferences. In addition, you may want to close applications you aren't using via the Multitasking Switcher (Double press the Home button and swipe an app preview up and out of the list).
Settings > General > Background App Refresh


Turn Off AirDrop when youre not using it
You should turn off AirDrop when you do not need it. This prevents you from using Bluetooth and Wi-Fi when not in use when the device is in discoverable mode. Simply swipe up on control center to turn it off.
Control Center


Turn Off Automatic Downloads and Updates
iOS 7 brings the ability to automatically update apps, however that works in the background and can take a toll on your battery life. Tap the settings icon, scroll down to iTunes & App Store and turn off all automatic downloads. If you still want automatic app updates, try enabling them while turning off cellular data.
Settings > iTunes & App Store


Brightness
Brightness is the most obvious battery-draining cause on the iPhone. Obviously, try to limit and reduce your brightness at all times. Going a step further, you can disable automatic brightness to improve battery life since the phone will no longer check the ambient light and determine the best brightness.
Settings > Wallpapers & Brightness


Control your Push Notifications
Apples iOS is designed to in a way preserve battery life when using push notification. That is, the number of push notifications you receive have a minimal effect on battery life. However, when receiving notifications that cause your screen to light up and phone to vibrate, your battery life will be affected. We recommending setting some notifications to not show any alerts. You can set alerts to 'None' on a per app basis.
Settings > Notification Center


Disable Email Push
Push emails immediately send an email or 'push' from a server to your phone, rather than requiring you to manually refresh the mail app. You can set the mail application to fetch instead of push, or even better, set to manual for best battery life. You can fine tune this setting for each email account, but for best battery life performance, set all accounts to Fetch Manually.
Settings > Mail, Contacts, Calendars > Fetch New Data > Push


Frequent Locations
iOS 7 brings a new Frequent Locations feature. While this new addition can be great for your Today tab in Notification Center by giving you an estimated time of arrival to your most visited locations , it can affect battery life. To turn this off, visit
Settings > Privacy > Location Services > System Services, then toggle the Frequent Locations to the off position.


Location Services
iOS has many system location services that check your location to improve compass calibration, cell network search, and more. We recommend turning off most of these system services to improve battery. However, if you use the compass often, or travel often, some settings should be left on such as Compass Calibration or Setting Time Zone. We leave Cell Network Search on as well.

Apps must request approval from you as well. If you really need location services for an app, obviously leave them on. However, you might not want some applications to fetch your locations, so feel free to toggle them off here as well. For instance, if you dont care for Twitter tweeting your location, turn it off!


Disable Wi-Fi & Bluetooth when not in range, Turn on Wi-Fi when in range
Be sure to always turn off Wi-Fi when youre out of range of a known network. This prevents the iOS device from constantly checking for known networks in range. Whenever you can use Wi-Fi, use it! Wi-Fi is much more efficient than cellular data so you can save battery this way. Be sure to set Ask to Join Networks off to stay connected to that network. Similarly, be sure to turn off Bluetooth at all times that you can.
Settings > Wi-Fi
Settings > Bluetooth


Disable Cellular Data
If you dont care for using cellular data for some apps and services, turn them off. iOS has many different toggles for cellular data use and some are hidden, so be sure to check all of them listed below!

Settings > Cellular
Settings > Safari > Reading List
Settings > iTunes & App Store


Reduce Motion
iOS 7 brings a nice parallax effect on icons and alerts, but this constantly tracks your motion to provide the effect. Reduce motion to prevent this and improve battery life.
Settings > General > Accessibility > Reduce Motion


Dont use Dynamic Moving Wallpapers
iOS 7 comes with dynamic wallpapers that move around based on the movement of your device. These moving backgrounds consume much more battery power than regular wallpapers so we recommend that you stay away from them and use Still wallpapers.
Settings > Wallpapers & Brightness > Choose Wallpaper


Disable Siri Raise to Speak
Disable Siri's raise to speak function to prevent the iPhone from constantly checking the proximity sensor to see if the device has been raised to your ear.
Settings > General > Siri


Turn Off Spotlight Search to prevent file indexing
Spotlight indexes your entire devices filesystem to provide instant search results of your most used contacts, apps and more. Indexing can cause a strain on the battery life, so try to turn OFF any items on the list that you dont use to prevent the OS from indexing that type of data.
Settings > General > Spotlight Search


Vibrations
Having your phone constantly vibrate can affect battery life as well, but having a vibrate feature is extremely useful. Try to disable vibrate for some contacts/notifications/text messages.
Settings > Sounds

Cellular Data
If youre in a 4G Area only, we recommend turning off LTE connectivity. Leaving LTE on actually drains the battery by constantly checking for an LTE signal (and if your carrier does not have LTE in your area, this is a waste). Similarly, if youre in a 2G area only, disable 4G/LTE connectivity as well.

However, if you are in an LTE area, we recommend leaving LTE on since Apple actually cites better browsing (in hours) on LTE versus 4G connectivity.

Settings > Cellular > Enable LTE


Auto-Lock
Set Auto-Lock to 1 Minute to reduce the amount of time it takes for the iPhone's display to shut off. Better yet, always lock the device immediately after use to prevent the ~1 minute your display would be on.
Settings > General > Auto-Lock


Use Airplane Mode when in an area without cellular service
If youre in a known dead zone that has no cellular service, turn on Airplane mode until your reach an area with cellular service. This prevents the phone from constantly checking for a signal, and can be a main cause of battery drain.


Turn off iTunes Wi-Fi Sync in iTunes
If you dont use Wi-Fi Sync, and often leave your iTunes open on the same network as your iPhone, turn off Wi-Fi sync.

Turn off Home Sharing
Streaming a movie or song from a computer to your iOS device can cause a huge battery drain. We recommend not using home sharing at all unless it is a feature you really like.
Settings > Music
Settings > Video


Set up as new iPhone
If you previously had a jailbreak, and no longer have one, try setting up an iPhone as new instead of restoring form backup. This way you dont restore unnecessary files.

Equalizer
Some users claim that turning off iPod equalizer will improve battery life, but in our tests (and others across the web) this does not seem to be the case. But if you really want to, turn off equalizer.
Settings > Music > EQ


Limit Ad Tracking
There are some reports that limiting ad tracking might improve your battery life. You may want to experiment with this setting to determine if it makes a difference on your device.
Settings > Privacy > Advertising > Limit Ad Tracking