I've been bitching and moaning about battery life for as long as there have been luggables, and I feel like I've lugged most of them, starting with a 28-pound Compaq 286 Portable (aka the sewing machine) back when I was still a pup, relatively speaking.

In July I wrote about a class-action suit filed against Intel for its -- shall we say "optimistic"? -- claims of notebook battery life ("Assault with batteries"). I also detailed my own sorry struggle trying to squeeze more juice out of my portable gear over the years. Since then I've heard from a few readers who've echoed my sentiments.

[ Also on InfoWorld: "Assault with batteries" | Stay up to date on Robert X. Cringely's musings and observations with InfoWorld's Notes from the Underground newsletter. ]

M. C., a professor at a well-known university in the Midwest, says battery life has actually gotten worse over the past 20 years:

The one laptop that I had that actually lived up to its battery life promises was my Zenith 80286 that gave me 6 hours of working time. I used it to research my thesis and spent an 8 hour day in an archives every day, and would take my notes on the laptop. It always gave me a full day's work. I would plug it in at night and do it all over again the next day. How I wish that 1987 technology was still with us!

Professional support tech D. S. B. sees a conspiracy afoot, citing the ridiculously high price of replacement batteries (often 25 percent of the cost of a new notebook) coupled with their propensity to simply up and die overnight without warning. To wit:

...about 5 months ago I powered up my Dell Inspiron 6400 laptop and was startled by a warning message that the battery was now dead and needed to be replaced, along with requisite contact information for how I could purchase one from Dell. Prior to that day, the battery continued to charge and hold a charge as normal. Granted, again, not as long as new, but certainly acceptable and at least an hour. Now, all of a sudden, Whap! The battery would no longer take or accept a charge. ... There is simply no reason why a previously working battery would all of a sudden drop off the useful list and Dell would be so "helpful" in pushing me toward dropping an exorbitant amount on a replacement. Call it captive revenue.

On the other hand, Cringe fan S. E. says he's always gotten close to the advertised amount of juice from his PowerBooks and MacBook Pro (unless he's watching a movie, in which case it drops to about 60 percent). So maybe it's a Windows thing?

Back in July, I also promised to give the Acer Timeline 3810T a whirl. The 3810T is a sweet little ultrathin with a sharp 13-inch screen and a roomy keyboard, yet it weighs just 3.5 pounds. It also claims to provide at least 8 hours of battery life, thanks to its Intel ultra-low-voltage chips.

At the time, I said if I got 8 -- or even 6 -- hours of battery life, I'd eat my fedora, washed down by a frosty malted beverage. Well, my hat is still intact. Here's the story.

I'd originally intended to test the Timeline on my trip to Korea in August. I opened the notebook at the start of my 14-hour flight and immediately found myself staring at a 3.5-pound paperweight. After working fine for several weeks prior, that battery up and died when I needed it most, just like it did for D. S. B. above.

But the Timeline worked just fine while plugged in, and there happened to be an AC outlet at my seat, so I didn't have to spend my whole trip watching straight-to-video movies while the flight attendants brought me yet another round of soju, which is kind of a cross between sake and rubbing alcohol. (For the record: Those Korean Airline stews [video] are the best in the biz. Seriously.)

I got a new battery and tried again, this time on a recent 8-hour flight from Copenhagen. I used it in power-saving mode, which dimmed the screen but otherwise didn't seem to have much effect on the notebook's performance, and used it as I normally would: with the Wi-Fi on, running a browser, e-mail, and a word processor. (There's no DVD drive, and I didn't watch any downloaded or streaming video.) I put it to sleep and woke it up as needed.

The good news is that I squeezed more life out of the Timeline's battery than that of any portable machine I've ever used. The bad news is that it didn't come close to giving me 8 hours -- more like a shade under 5.

Some reviewers, like Laptop Magazine's Dana Wolman, found the machine to deliver 8 hours on standard tests. Also, the in-flight movie sucked, and US Airway's flight crews aren't in the same league as KAL's. But I digress.

The power management software on that model, on the other hand, is totally insane. At one point, it assured me I had 177 hours and 42 minutes of battery life remaining. I'm not kidding.

When I told Acer about it, I got this response: "We've seen high estimates before... but none that high! Wouldn't it be great if it were true? Gosh, we can only dream. ;) The lower the battery life, the more accurate [the meter] is. Also, as the system runs more on battery, the more accurate it becomes."

Switching between "power saver," "balanced," and "high performance" had virtually no impact on how much time it guessed I had left at any moment. In fact, it kept telling me that by choosing power saver, I wasn't using the most efficient setting for the battery. Hello?

This probably has more to do with Vista being brain dead than a problem with Acer's technology. And I probably could have eked out a few more minutes here or there by diving deep into Vista's power management settings and tweaking them. But why should you have to do that?

This got me to thinking, though. At this point in the evolution of technology, I should be able to get 177 hours and 42 minutes out of a computing device. If batteries had followed or surpassed Moore's Law, the way chips and memory and storage and displays have, we'd be there already. I think some of the problem has to do with how computers are engineered, as well as the deeply inefficient way Windows uses memory and storage. But there seems to be no fixing that.

Also, I want a jet pack. I was promised one as a child, and I'm still waiting. But I'll settle for a laptop I can carry with me across the pond and beyond, without having to hunt for a three-pronged outlet every few hours.

What do you long for from tech but cannot seem to get? E-mail me: cringe@infoworld.com.

This story, "The 8-hour Laptop: Don't Hold Your Breath" was originally published by InfoWorld .