“Microsoft says it is investigating reports of notebooks with poor battery life with Windows 7, as first reported by users on Microsoft TechNet. These users claim their batteries were working just fine under Windows XP and/or Windows Vista, and others are saying it occurs on their new Windows 7 PCs.”
Microsoft Looking Into Windows 7 Battery Life Failures
2010-02-02 Windows 6 Comments
The same thing happened to me last June when I installed the RC on a laptop. For about 6 months, my battery life (as XP reported it) would suddenly drop from 60% to 4 or 5% – then I’d still get another 45 minutes before the battery actually drained.
Windows 7, however, would automatically put the laptop into sleep mode when the battery reached 5% (I fiddled with the power management settings a little, but couldn’t find any way to change that). It was especially annoying the first that happened: while I was trying to watch a movie during a long bus trip.
Had the problem with Win7 final on an Asus EEE 1000HE. Yes yes, I know, Windows 7 is not officially supported on that netbook, yada yada yada. That’s still no reason for the battery life to be as awful as it was. The provided install of XP would yield about 7.5 to 8 hours of battery, my tweaked Ubuntu install could get up to 9. With 7, I would be lucky to get 6 out of it and the CPU was always running hotter than it should even once the ACPI drivers and Eeectl were working properly.
After replacing XP on my Dell XPS 1210 with Windows 7, my battery uptime raised from 4hours to 6hours under load.
So this current story is B.S.