There are certain times when you want to extend the battery life of your iPhone so the battery doesn't die when you need access to your phone. For those times when it is critical to have a working iPhone, you may need to configure your phone to conserve its battery life. Whether you need to leave your phone on for a long period of time because you're expecting a call or you forgot your iphone charger on a trip and can't re-charge your phone, the following tips from Apple will help save battery life and extend the hours you can keep your iPhone on.
"Heat will degrade your battery’s performance the most." So be sure to keep your iPhone out of the sun or in a hot car. Try to keep your iPhone at as close to room temperature as possible (72° F or 22° C) is best.
Tip 1 : Minimize use of location services:
Applications that actively use location services such as Maps may reduce battery life. To disable location services, go to Settings > General > Location Services or use location services only when needed.
Tip 2 : Fetch new data less frequently:
Applications such as Mail can be set to fetch data wirelessly at specific intervals. The more frequently email or other data is fetched, the quicker your battery may drain. To fetch new data manually, from the Home screen choose Settings > Fetch New Data and tap Manually. To increase the fetch interval, go to Settings > Fetch New Data and tap Hourly. Note that this is a global setting and applies to all applications that do not support push services.
Tip 3 : Turn off push mail:
If you have a push mail account such as Yahoo!, MobileMe or Microsoft Exchange, turn off push mail when you don’t need it. Go to Settings > Fetch New Data and set Push to Off. Messages sent to your push email accounts will now be received on your phone based on the global Fetch setting rather than as they arrive.
Tip 4 : Auto-check fewer email accounts:
You can save power by checking fewer email accounts. This can be accomplished by turning off an email account or by deleting it. To turn off an account, go to Settings > Mail, Contacts, Calendars, choose an email account, and set Account to Off. To remove an account, go to Settings > Mail, Contacts, Calendars, choose an email account, and tap Delete Account.
Tip 5 : Minimize use of third-party applications:
Excessive use of applications such as games that prevent the screen from dimming or shutting off or applications that use location services can reduce battery life.
Tip 6 : Turn off Wi-Fi:
If you rarely use Wi-Fi, you can turn it off to save power. Go to Settings > Wi-Fi and set Wi-Fi to Off. Note that if you frequently use your iPhone to browse the web, battery life may be improved by using Wi-Fi instead of cellular data networks.
Tip 7 : Turn off Bluetooth:
If you rarely use a Bluetooth headset or car kit, you can turn off Bluetooth to save power. Go to Settings > General > Bluetooth and set Bluetooth to Off.
Tip 8 : Use Airplane Mode in low- or no-coverage areas:
Because your iPhone always tries to maintain a connection with the cellular network, it may use more power in low- or no-coverage areas. Turning on Airplane Mode can increase battery life in these situations; however, you will be unable to make or receive calls. To turn on Airplane Mode, go to Settings and set Airplane Mode to On.
Tip 9 : Adjust brightness:
Dimming the screen is another way to extend battery life. Go to Settings > Brightness and drag the slider to the left to lower the default screen brightness. In addition, turning on Auto-Brightness allows the screen to adjust its brightness based on current lighting conditions. Go to Settings > Brightness and set Auto-Brightness to On.
Tip 10 : Turn off EQ:
Applying an equalizer setting to song playback on your iPhone can decrease battery life. To turn EQ off, go to Settings > iPod > EQ and tap Off. Note that if you’ve added EQ to songs directly in iTunes, you’ll need to set EQ on iPhone to Flat in order to have the same effect as Off because iPhone keeps your iTunes settings intact. Go to Settings > iPod > EQ and tap Flat.
Tip 11 : Turn off 3G:
Using 3G cellular networks loads data faster, but may also decrease battery life, especially in areas with limited 3G coverage. To disable 3G, from the Home screen choose Settings > General > Network and set Enable 3G to Off. You will still be able to make and receive calls and access cellular data networks via EDGE or GPRS where available.
Those are some very useful tips that Apple suggests to help conserve the battery life of an iPhone. I would also suggest that you keep your iPhone updated with the latest Software Version for the iPhone (currently 2.2.1) using iTunes, because new software updates for the phone may encompase software tweaks that could help extend the battery life of your iPhone.
Also, note that if you are charging your iPhone and notice that the phone gets very hot, be sure to remove it from it's case (if you're using an iPhone case) so the phone can breathe. Excess heat while charging your iPhone can affect the capacity of the iphone battery.