Battery Life Tips of your iPhone

The iPhone 3G’s battery life is either terrific or terrible, depending on your
point of view. When accessing the 3G network, it gets longer battery life than
any other phone—and yet that’s only 5 hours of talk time, compared with 8
on the original iPhone.
But never mind all that; the point is that if you’re not careful, the iPhone 3G’s
battery might not even make it through a single day without needing a
recharge. So knowing how to scale back its power appetite could come in
extremely handy.
The biggest wolfers of electricity on your iPhone are its screen and its wireless
features. Therefore, you can get longer life from each charge by:
• Dimming the screen. In bright light, the screen brightens (but uses
more battery power). In dim light, it darkens.
You can use this information to your advantage. By covering up the sensor
as you unlock the phone, you force it into a low-power, dim-screen
setting (because the phone believes that it’s in a dark room). Or by holding
it up to a light as you wake it, you get full brightness. In both cases,
you’ve saved all the taps and navigation it would have taken you to find
the manual brightness slider in Settings.
• Turning off 3G. If you don’t see a 3 icon on your iPhone 3G’s status bar,
then you’re not in a 3G hot spot , and you’re not getting any
benefit from the phone’s battery-hungry 3G radio. By turning it off, you’ll
double the length of your iPhone 3G’s battery power, from 5 hours of talk
time to 10.
To do so, from the Home screen, tap SettingsÆGeneralÆNetworkÆ
Enable 3G Off. Yes, this is sort of a hassle, but if you’re anticipating a long
day and you can’t risk the battery dying halfway through, it might be
worth doing. After all, most 3G phones don’t even let you turn off their
3G circuitry.
• Turning off Wi-Fi. From the Home screen, tap SettingsÆWi-FiÆOn/Off.
If you’re not in a wireless hot spot anyway, you may as well stop the thing
from using its radio. Or, at the very least, tell the iPhone to stop searching
for Wi-Fi networks it can connect to..
• Turning off the phone, too. In Airplane mode, you shut off both Wi-Fi
and the cellular radios, saving the most power of all.
• Turning off Bluetooth. If you’re not using a Bluetooth headset, then for
heaven’s sake shut down that Bluetooth radio. In Settings, tap General,
and turn off Bluetooth.
• Turning off GPS. If you won’t be needing the iPhone to track your location,
save it the power required to operate the GPS chip and the other
location circuits. In Settings, tap General, and turn off Location Services.
• Turning off “push” data. If your email, calendar, and address book are
kept constantly synced with your Macs or PCs, then you’ve probably gotten
yourself involved with Yahoo Mail, Microsoft Exchange
or MobileMe . It’s pretty amazing to know that your iPhone is
constantly kept current with the mothership—but all that continual sniffing
of the airwaves, looking for updates, costs you battery power. If you
can do without the immediacy, visit SettingsÆFetch New Data; consider
turning off Push and letting your iPhone check for new information, say,
every 15, 30, or 60 minutes.