I found this info on battery life in reference to wlan transmission power options. https://maemo.org/bugzilla/show_bug.cgi?id=256 "The option of choosing the 10 mW transmission power is there only because certain countries require this in their law. The low power transmission has a negligible effect on the battery lifetime because the data is sent in short bursts that last for less than 1% of total time. On the other hand, the lower transmission power will make it harder to keep connected. Therefore it is best to use the (default) 100 mW power, unless legislated otherwise in the law of your country."