You may have noticed right off with your iPhone that you can not pull the battery out and put in another fully charged one. Apple chose to seal the battery inside like they have done on all of the iPod line.
There are a few fine tuning tips you can do to get more hours of usage between charges. Which ones you use will depend on how you uses your iPhone; Internet usage via Cell connection, lower quality cell signal areas, bluetooth headset, WiFi networks, music listening, brightly lit areas, and email checking. All of the tips on setting changes are easy to flip back and forth so you can tune as you needs change day to day.
Starting off with the adjustment tips, from the ‘Settings’ icon;
Airplane Mode: if you don’t need to use your iPhone as a phone for a while, flipping this switch to ‘on’ (like you would if you were flying) turns off all Cell and Wifi antennas which are both big power users.
WiFi: Do you use WiFi Internet access? If no, then turn it off so power isn’t used for the iPhone to continuously search for a WiFi Internet connection.
Fetch New Data. If you don’t use MobileMe to sync your data with your desktop data, turn this feature off. If you do like having this sync feature, change the sync timing to a longer time between the ‘Fetch’. Setting to sync ONLY the items your syncing through MobileMe cuts down on the connection time to use less power too – otherwise the iPhone’s system is spending time hunting for things that aren’t there.
Brightness. If this is set to Auto-Brightness – the screen will brighten when your in brightly lit areas (like outside). Turning this on/off will have different battery life results depending where you use the phone. Turn it off and set the screen brightness on the lower end will use less power but may not be usable outside – you will want to play with this setting if you choose.
General – has setting tuning items:
Network – Do you use the Internet via your Cell connection? If you do not, turning off the 3G connection will extend your battery life. As well, if your in a area that has low 3G coverage you might see less call drops as the phone fights to stay connected to a 3G network over the Edge network. Choosing to disable the 3G network, you will still have Cell Internet access, just slower. Another power impact from 3G is as you move through 3G supported areas, your iPhone will constantly hunt for the best signal rather than resting on a Edge speed connection.
Bluetooth – if you do not use a Bluetooth headset, turn this off. Otherwise the Bluetooth antenna uses power looking for a device to communicate with.
Location Services – a cool feature of many applications is to use your current location to fine tune the information your requesting. If you do not care about applications knowing where you are, turn this feature off. Otherwise, every time you use one of those apps, you will use a lot of power while the iPhone talks to the systems to find it’s self in the world.
Turning the screen off as soon as you no longer need it on. Since touching the screen of your iPhone or Touch with anything other than a finger wont do anything, most people just slip their iPhone / Touch in their pocket with the screen still on. Turning the screen off with a tap of the button on the top of the unit is very fast and will save a lot of power by the end of the day.
Speaking of turning the screen off… it is good to do when listening to music. Your songs will continue to play with the screen off. If you need to jump to the next song or pause the current one, no need to ‘unlock’ and go to the iTunes area. Just click the Home button twice and your music controls will appear right away.