iPhone - FutureTG.com

a lightning bolt to let you know that it’s charging. If it’s locked, pressing the
Home button shows you a battery gauge big enough to see from space.
Battery Life Tips
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.
This works because of an ambient-light sensor that’s hiding behind the glass
above the earpiece. Apple says that it tried having the light sensor active all the
time, but it was weird to have the screen constantly dimming and brightening
as you used it. So the sensor now samples the ambient light and adjusts the
brightness only once—when you unlock the phone after waking it.
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 (page 302).
• 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 (page 11), 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
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