Borreltje, type in "top" without the quotations into the terminal (x-terminal). I'm testing this myself, so far 4 hours from odd charger. Battery is down to 3/4th indicator. No CPU eating processes I can see are running (though top won't list drivers that are in use or not). WiFi shouldn't be powered on since I rebooted the N900 before testing and it's been using 2.5/3G from since then.