Chapter 3 Basics 39
Important: The iPhone battery may drain instead of charge, if iPhone is connected to a computer
that’s turned o or is in sleep or standby mode.
The battery icon in the upper-right corner shows the battery level or charging status. To display
the percentage of battery charge remaining, go to Settings > General > Usage. When syncing or
using iPhone, it may take longer to charge the battery.
Important: If iPhone is very low on power, it may display an image of a nearly depleted battery,
indicating that iPhone needs to charge for up to ten minutes before you can use it. If iPhone
is extremely low on power, the display may be blank for up to two minutes before one of the
low-battery images appears.
Rechargeable batteries have a limited number of charge cycles and may eventually need to
be replaced. The iPhone battery isn’t user replaceable; it can be replaced only by an authorized
service provider. See www.apple.com/batteries/replacements.html.
Travel with iPhone
If you travel outside your carrier’s network area, you can avoid roaming charges by turning o
voice and data roaming services in Settings > Cellular. See Cellular settings on page 149.
Some airlines let you keep your iPhone turned on if you switch to Airplane Mode. You can’t make
calls or use Bluetooth, but you can listen to music, play games, watch videos, or use other apps
that don’t require network or phone connections. If the airline allows it, you can turn Wi-Fi or
Bluetooth back on to enable those services, even while in Airplane Mode.
Turn on Airplane Mode. Swipe up from the bottom edge of the screen to open Control Center,
then tap . You can also turn Airplane Mode on or o in Settings. When airplane mode is on,
appears in the status bar at the top of the screen.
Wi-Fi and Bluetooth can also be turned on or o in Control Center.
