Pretty sure with 3g on and mp3's playing and constantly turning pages + using webbrowser you'll get like 3-4 hours even with optimal 3g coverage.
You can do the maths of how much power the display draws from the battery to refresh itself (1 page turn alone) and I'm pretty sure that alone is > than 10k page turns. On the DX model it's probably greater than 5k... e-ink displays are not THAT energy efficient. The board does use energy, and the 3g module does consume an enormous amount when it is active.
Oh, and my laptop using standard cell battery is said to last 4-5 hours with stock Windows 7.
Normally with Wifi On Browsing the Net I get 3-4.
Disabling FLASH player and turning of WINDOWS AERO interface I get 4-5 easily, which is up to spec.
Gaming is a completely other matter.
Without wifi/bluetooth, and no utilization of the gfx chipset I can easily get 5 hours, all with 100% backlighting, so appearantly DELL does not lie about their battery life.
Amazon version would be: "Long battery life, up to 3 weeks of standby, or two days" ... in the vacuum of space, with the back light off, hard drive spun down, 3d chip set disabled, sound muted, wifi+bluetooth off, processor underclocked to 5%, using notepad for 10 minutes every 3 hours for 2 days...
Last edited by curstpriest; 11-09-2010 at 12:47 PM.