1Connect the small end of the USB cable to the charger/microUSB connector. The silver circle on the cable faces the front of the smartphone.
2Connect the other end of the USB cable to the AC charger.
3Plug the AC charger into a working socket.
TIP You can also charge your smartphone battery by connecting your smartphone to your computer using the USB cable. Charging this way takes much longer than using the AC charger. Do not, however, connect a Touchstone (sold separately) to your computer.
Maximising battery life
Battery life depends on how you use your smartphone. You can maximise the life of your battery by following a few easy guidelines:
•Charge your smartphone whenever you can. Charge it overnight.
•Set your screen to turn off automatically after a shorter period of inactivity (see Set the interval for turning the screen off automatically).
•Keep your battery away from direct sunlight and other sources of heat. Temperatures over 45 degrees Celsius can permanently reduce the capacity and life span of any
•As with any mobile phone, if you are in an area with no wireless coverage, your smartphone continues to search for a signal, which consumes power. Turn off the phone if you are outside a coverage area
(see Turn wireless services off (aeroplane mode)). If you live or work in an area of poor coverage, you might consider purchasing a signal booster (sold separately) from your wireless service provider. These typically connect to your broadband Internet connection, if available.
•If you set up an email account in the Email application, set the interval to automatically download email to every two hours or less frequently (see Enter advanced account settings).
•Lower the screen brightness (see Change screen brightness).
•Use a
•Keep in mind that frequent use of instant messaging (IM) can reduce battery life. Sign out of your IM account when you are not using it (see Sign out of an IM account).
•Shut down the smartphone completely when you won't be using it for an extended period of time (see Shut down your smartphone).
TIP If you think that the battery needs to be replaced, see I need to replace the battery for instructions.
Turn your smartphone on/off
The screen on your HP Pre3 can be turned on and off separately from its wireless services (which are the Phone 
app, 
app, Bluetooth® 
app and VPN 
app). This means you can wake up the screen to use just the organiser features of your device (Calendar, Contacts, Tasks, Memos and so on) without turning on the phone and other wireless features. Also, when the screen is turned off, the phone can be on and ready for you to receive phone calls or messages.
Why the screen goes dark
If you hold the smartphone up to your ear while on a call, the screen goes dark. This is normal behaviour. It prevents your accidentally tapping an
18 Chapter 2 : Basics