"Just take these precautions - Features that use Bluetooth technology, or allowing such features to run in the background while using other features, increase the demand on battery power. Turn Bluetooth technology off when you do not need it.   Features that use Wireless LAN (WLAN), or allowing such features to run in the background while using other features, increase the demand on battery power. WLAN on your Nokia device switches off 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 set Packet data connection to When available in 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 scroll 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 UMTS network. To use only the GSM network, select Network mode > GSM.  The backlight of the display increases the demand on battery power. In the display settings, you can change the time-out after which the backlight is switched off, and adjust the light sensor that observes lighting conditions and adjusts the display brightness.  Leaving applications running in the background increases the demand on battery power. Close application you do not use." - Dan Smith