PC makers are lying to you about battery life

...well not exactly, but they're certainly not giving you an accurate picture of how long it will take for your laptop battery to run down next time you're using it.

...well not exactly, but they're certainly not giving you an accurate picture of how long it will take for your laptop battery to run down next time you're using it.

A post on the Bits blog yesterday asks a great question: "Why can't we get an accurate battery life test for laptops?" In the post, writer Ashlee Vance notes that the very people that are -- how should I say this, stretching the truth? -- about how long your notebook battery will last under normal use are actually making moves to offer consumers a more accurate rating.

The problem, it seems, is that many manufacturers use the MobileMark 2007 test, which includes "having the screen at just 20 percent brightness, Wi-Fi turned off and no music, video, games or Web pages running."

Typical real-world usage, right?

(Here's an indication of how off-the-mark that is in 2009: I'm currently using my laptop at 85% brightness with Wi-Fi on. I'm streaming music from Last.fm in one of three tabs of Safari, have another five tabs of Firefox open and have Microsoft Entourage open to receive mail. All while chatting over IM with ZDNet's West Coast editor Sam Diaz.)

The plan, according to AMD (whose genial marketing VP Pat Moorhead was interviewed in the post), is to try to develop a dual battery life measure to post on machines: one that reflects MobileMark test results and one that shows battery life under video and gaming duress.

Think of it like mileage for your car: highway and city. (In this scenario, however, the highways are mostly barren.)

The problem, of course, is that it will take years to get all manufacturers on board. And the sniping that Intel and AMD are privvy to (evident in the Times post) won't help them get any further along, either.

So let's have ourselves a bit of a poll, shall we?

Post your observed battery life in the comments and a summary of what you've typically got running on your system, home or work.

Perhaps if enough people contribute, we'll get a better sense of how people -- ZDNet readers, at least -- really use their computers.