I updated from 11.04 to 11.10 earlier this week, and though I'd heard reports of increased power usage on oneric, this is crazy.
I have a relatively new Lenovo x220 (core i7) with a 9-cell battery. With screen dimmed a bit and intermittent wifi use under Windows 7 I can easily get 8+ hours (and could push it to 12+ using Lenovo's power-usage tweaks). On Ubuntu 11.04 I still got a decently respectable 6+ hours. On Oneric, I'm getting around 4 hours with wifi turned off - that's a third of the battery life I can get on Windows. This is unacceptable.
What the heck is going on? I've heard this is somewhat kernel related, but even so, this seems insane to me. I've been on Ubuntu for six years and hate the prospect of having to turn back to Windows. I opted for this laptop specifically for the battery life, and the insane power consumption is making 11.10 practically useless for me. I'm tempted to revert all the way to 10.10 to see if I can at least get 7 hours with gnome2 and an older kernel.
Can we expect a fix anytime soon? Have the developers publicly commented on this? Is it even being acknowledged? Given how much of a mobile emphasis Ubuntu has had in recent years (netbook edition etc), it seems like they're shooting themselves in the foot releasing a distro that throws portability out the window.
(Relatedly, did something change in powertop? In previous Ubuntu releases, the stock powertop available in the repos would give me a useful realtime power consumption report along with an estimate of how much juice was left - the powertop on 11.10 seems to offer a bunch of confusing separate tabs with very little useful information.)