Lowering Screen BrightnessMost people don't realize it, but their iPhone's brightness level is set too high. While a very bright setting looks good, it is a large drain on the battery. By lowering your brightness, not only can you save the battery life, but you can also make the screen easier on your eyes, especially when viewing the iPhone in the dark. At first the lower brightness may look worse, but with a little time, your eyes adjust to it and you will forget that you ever changed it.
Turning off Wi-FiContinually searching for Wi-Fi causes a significant drain on your battery. If you do not need Wi-Fi but are still using your phone, it is best to turn it off. You can find the setting to turn off Wi-Fi from the home page by going to Settings, then Wi-Fi. There you can turn Wi-Fi off.
Turning off BluetoothIf you are not using a bluetoooth headset it is best to turn bluetooth off.
Reducing Auto-Lock TimeA higher auto-lock timer makes your phone use the battery even if you're done using it. Consider lowering the auto-lock time to 1 or 2 minutes. This will put your phone in sleep mode and will conserve your battery power for when you actually need to use it.
Close apps beforing locking the iPhoneWhen you keep applications open before putting it in sleep mode, depending on the app, it could be draining your battery life. Always make sure to shut down all applications before you lock your phone to conserve the battery.
Vibrate drains battery powerThe vibrate option uses a lot of battery power so consider turning it off if you can live with just a ring. Unless you are somewhere where phones are not allowed, you probably do not need the vibrate option anyway.
Upgrade the firmwareYou should frequently check for the latest firmware updates for your iPhone from Apple. Firmware updates boost both performance and include feature updates. Better battery life can sometimes be one of the updates.
Turning off notificationsTurning off push notifications conserves battery power a lot, so turn them off if you can live without them.
Turning off push e-mailPush e-mail also has a considerable drain on the battery.
Disabling vibration while playing gamesWhen vibration is used in an iPhone game, it drains the battery power a lot, it is recommended to turn vibration off while playing games.
Location ServicesTurn off apps that use location services by going to Settings, General, Location Services and select the apps you don't want using this feature.
This video will also provide you with some more iPhone battery saving secrets:
If you have your own tips on how to conserve the battery life of the iPhone, please post them in the comments section below. Thank you.