Many features in your device increase the demand on battery power and reduce the battery lifetime. To save battery power, note the following:
Features that use Bluetooth connectivity, or allowing such features to run in the background while using other features, increase the demand on battery power. Deactivate Bluetooth connectivity when you do not need it.
Features that use Wi-Fi, or allowing such features to run in the background while using other features, increase the demand on battery power. Wi-Fi connectivity is deactivated when you are not trying to connect, not connected to an access point, or not scanning for available networks. To further reduce battery consumption, you can specify that your device does not scan, or scans less often, for available networks in the background.
If you have selected Packet data connection > When available in the connection settings, and there is no packet data coverage (GPRS), the device periodically tries to establish a packet data connection. To prolong the operating time of your device, select Packet data connection > When needed.
The Maps application downloads new map information when you move to new areas on the map, which increases the demand on battery power. You can prevent the automatic download of new maps.
If the signal strength of the cellular network varies much in your area, your device must scan for the available network repeatedly. This increases the demand on battery power.
If the network mode is set to dual mode in the network settings, the device searches for the 3G network. To set the device to use only the GSM network, select Menu > Settings and Connectivity > Network > Network mode > GSM.
The backlight of the display increases the demand on battery power. In the display settings, you can adjust the display brightness and change the time-out period after which the backlight is switched off. Select Menu > Settings and Phone > Display > Brightness or Light time-out.
Leaving applications running in the background increases the demand on battery power. To access the applications you are not using, press and hold the menu key, and select an application.