Press the Power key > Activate power saving. To deactivate power saving mode, press the Power key > Deactivate power saving.
When activated, the power saving mode turns off some functions automatically. Radio configuration in power saving mode include the cellular radio (it is set to 2G/GSM only mode), the Bluetooth radio (it is turned off) and the Wi-Fi/WLAN radio (scanning for new networks in turned off but existing networks keep functioning). The power saving mode also reduces display power consumption by minimizing screen brightness and by turning off touch screen feedback and theme effects. In addition the vibra alerts are turned off in a power saving mode.