Slashdot Mirror
Lies, Damn Lies, and Battery-Life Statistics
theodp writes "What if automakers measured gas mileage by rolling their cars downhill with their engines idling? They might, Newsweek's Daniel Lyons suggests, if they took inspiration from the MobileMark 2007 notebook battery-life benchmark test, the creation of a consortium called BAPCo, whose members are — surprise — computer makers and other tech companies. Laptops score big numbers, Lyons explains, because they're tested with screens dimmed to 20%-30% of full brightness, Wi-Fi turned off, and the main processor chip running at 7.5% of capacity. Professional reviewers see company-generated battery-life claims as a joke. 'The rule of thumb is that in real-world use you get about 50 percent of rated battery life,' says a Gizmodo associate editor. Leading the call for reform is the not-necessarily-altruistic AMD, who gripes that MM07 was created in Intel's labs and rigged so Intel chips would outscore AMD chips, which draw more power when idle."
Captain Obvious?
They would need a really big hill.
Take a look at Anandtech's MBP review. The tagline 'Battery life to die for' sort of gives away the tale though.
Apple claim 5-8 hours. Anand got 4.92 (heavy downloading + XVid + Web browsing) to 8.13 hours (Wireless web browsing) with the screen at half-brightness ("completely useable") and no funny optimisations.
Maybe, just maybe, there's something to this "our batteries are better" thing they've got going; if someone comes out with a spare-battery-attached-to-a-magsafe-connector for those die-hards who absolutely *need* it, angels may sing in the treetops. Personally I've never needed to change the battery in my portable (whatever portable I've had) so it's no big deal to me. Yadda yadda, one datapoint not a trend...
Simon.
Physicists get Hadrons!
Most people expect 2.5 hours of "good use" out of a laptop battery when new. This number hasn't really changed since 1998 or so. I can't remember the last time I used battery life when evaluating a laptop - if you NEED more than 2.5 hours of battery life, you just buy a second battery. People assume half the life stated as rule of thumb the same way I assume real world gas mileage as (EPA gas mileage * 0.8) for cars I drive.
The correct title for this article is "Does anyone still pay attention to marketing hype about batteries, or, how I learned to stop caring and ignore the marketing hype".
moox. for a new generation.
but I get five hours of battery life on a Macbook (last year's model), so I think Apple doesn't lie about its stats (because they don't have to?). Despite all the claims that Macs are overpriced, I think these are among the cheapest non-netbooks you can get with great battery life. IMO, laptops which last only 2.5 hours on a battery should not be sold.
People "expect" that just because they don't really realize it can be better. Put it another way: they don't expect that at all, they just accept it.
One that hath name thou can not otter
I wasn't very careful looking at the battery life, and, to my dismay, I took it home to find out it could only hold a charge for 1.5 hours. This is even on pretty conservative settings with the screen dimmed as low as possible. Now that it's starting to age, I'm down to about 1 hour of battery, which doesn't even last through my 75 minute classes.
Most people expect 2.5 hours of "good use" out of a laptop battery when new. This number hasn't really changed since 1998 or so. I can't remember the last time I used battery life when evaluating a laptop - if you NEED more than 2.5 hours of battery life, you just buy a second battery.
Oh, how I wish that were the case.
I have a cheap lenovo from last year and if I am on 50% brightness with wifi on and just browsing web with some videos I can go 3 hours. The battery is rated for 3. *shrug*
https://www.speakservers.com/
2.5 hours? Really? What's the point? My two and a half year old Thinkpad T60 gets 5 hours on a bad day. My friend with a similarly spec'd Thinkpad (a bit older) claims to have gotten 9 hours with wifi off and more like 7 hours in reasonable usage (his is tweaked a bit better). Both of us have just the extended battery (there is also space for a second, smaller battery instead of an optical drive).
Instead of complaining that the test is rigged, maybe creating processors that draw less power when idle would be a good idea?
I like big butts and I cannot lie.
I will never buy a laptop with a non-removable battery even if it gets 8 hours playing MMOs at full resolution. I *have* a Macbook Pro, and if it had an "iBattery" my laptop would have been destroyed when the battery failed and swelled... instead of having the battery pop safely out of its compartment.
Better battery, great, but I'll take a laptop that's a millimeter thicker if that's what it takes to put a door on the battery compartment.
If someone comes out with a spare-battery-attached-to-a-magsafe-connector for those die-hards who absolutely *need* it, angels may sing in the treetops
This is exactly why I don't understand the fuss over non-removable batteries. You get better battery life, and if you need extra power you've always been able to buy external battery packs. They have cable that attach to the Magsafe connector. You can get them in a range of sizes, including sizes that are not much larger than a spare battery would have been anyway...
Similarly there are tons of external packs for smaller devices like the iPhone/iPod (or anything usb charged).
I also have not often found the need for an second battery in a laptop if I can get at least three to four hours out of it. Basically the only time is an international flight, and for that the external batteries are perfect. Heck, until it broke the Solio solar powered recharger I had could even recharge itself in-flight as long as I was at a window!!
"There is more worth loving than we have strength to love." - Brian Jay Stanley
We saw the same issue with clock cycles. People misinterpreted, and the marketing drones were more than happy to let them do so, clocking as measure of work. A faster processor did not mean that more work would get done, but the consumer did not know that, so they would pay more for fantasy benefits.
In terms of fuel consumption, and battery life, the reality is more of the horsepower that the gigahertz. As long as one is running comparable tests, then one can assume that a car rated at 20 mpg will run longer than a car rated at 10 mpg, just like a computer that is rated for 4 hours will run longer than a computer rated at 2 hours. The problem, like the horse, is related the terms horse, hour, and mpg to actual physical quantities. We know that the physical performance is actual 20% or so less in real life.
As mentioned elsewhere, what messes life up is companies like Apple that advertise 3 hours of battery life, and, under normal use, actually get it.
"She's a scientist and a lesbian. She's not going to let it slide." Orphan Black
20 hours of rugged computing on the go. (Ok...rugged text entry.....) I want a netbook that captures the spirit of the Model 100.
http://en.wikipedia.org/wiki/TRS-80_Model_100_line
People are still using them (much less, unfortunately) today. I'd say there is a market for a long lasting computing device that is rugged.
zosxavius photography
In my own experience, I've found there are 3 different battery life numbers you run into with any laptops. These numbers are always significantly different.
1. The life the manufacturer tells you that you'll get /. readers) swear you'll actually get
2. The life every reviewer (and some
3. The life you actually do get
Regardless of 1 or 2, I've found that 2.5 hrs is a good ballpark for 3 when the laptop is new. (ok, for Apple, the newest one I've used is a bit over 2 years old, but was in that ballpark when new. My newer HP w/o the add-on battery is a little better than that, but same ballpark)
This challenge can be equally turned around.
For the sake of devil's advocacy:
Hey Intel, I have a challenge for you. Instead of rigging your battery life testing mechanisms, why not run your tests like real-world usage would do?
Also, frankly, I don't want a laptop that is unusable out of suspend mode, I want to be able to use my laptop while it's near idling. Yes, I use WIFI, and I also use my laptop to see things I want to see. So at this point, just for this reason, I'm glad my laptop has an Intel chip in it, and I'm glad I get those 2.5 hours of battery life (I'd be interested in after-market quality batteries fyi) I can't see how hard it would be to prove your measurements inaccurate.
There are no perfect answers, only the right questions. More questions at http://foresightandhindsight.blogspot.com/
Battery tech has improved, but the computer manufacturers use that extra ability to run more stuff. It's just like how computers don't seem to work any faster than they did ten years ago--advances in memory and processor power get eaten up by bloated software and additional "features". And 4-5 hours seems to be what most people consider acceptable; few are willing to trade off power, screen size/brightness, features, etc. for longer built-in battery life.
The meek may inherit the earth, but the strong shall take the stars.
Apple, like many companies, is often rather fearful of power adapter and battery issues. If you have a power adapter that's sparking, or a battery that's bulging, or something that might pose a safety risk, they'll often choose to replace it for you (in warranty or not) rather than let you continue using it, risk getting hurt, and starting a lawsuit (or a recall).
Obviously, this varies a lot. A fraying power adapter cord is also likely to be caused abuse, and they'll figure that you're smart enough that if it's sparking, you probably shouldn't use it while sitting in a pool of gasoline (or at all, for that matter). And even a bulging battery might be called a consumable, and they'll just tell you to buy a new one. It depends on a lot of things - if you have/had AppleCare, the mood of whoever you're talking to, how much money you regularly throw at Apple for new products, how widespread the problem is, how many times you ask, etc.
You don't seriously expect that the internal battery is any more "apple manufactured" than the removable battery was, do you?
Apple, like pretty much all the domestic PC brands, has little to no manufacturing capacity in-house. Possibly some prototyping, and likely some customization/assembly; but all the serious manufacturing is handled by a bunch of OEMs and their suppliers. The cells will be sourced from some third party in any case.
How appropriate, then, that the one thing they *do* oversee in-house is the manufacturing processes for the *cases*. They've invested quite a bit in manufacturing process development and patenting, resulting in things like the "Unibody" laptops and those highly-resilient aluminum coating materials.
So many of their customers, after all, "judge a notebook by its cover"...
Entomologically speaking, the spider is not a bug, it's a feature.
Just a guess, but since they typically dont run an antivirus app in the background, both cpu and disk can idle more.
Not trying to be a macista, but I can only note that I still get around 4h wifi surfing at medium brightness out of my two year old macbook, so apple definitely do give reasonably honest battery estimates.
WRONG.
No matter whether closed-loop or open-loop, modern FI always injects the amount of gas most closely matching the volume of air taken in.
Closed-loop (using the oxygen sensor in the exhaust) is totally adaptive, if there's unused O2, add more fuel. Open-loop (no O2 sensor, or 02 sensor not hot enough or not working or...) thet FI computer consults a table based on all the usual factors: Mass-air flow, engine temp, throttle position.
In either case, the opinion that your FI turns off the flow of fuel when you let off the gas is wrong. While the FI can indeed cut the fuel, it does so only under extremely rare conditions. I've actually never been able to make it happen on my car.
Oh, and the reasons? When you shut the fuel off, you run the risk of a lean mixture, which is both damaging to the engine (burning holes thu pistons) and super hi rush of NOx. That's why your throttle plate doesn't snap fully to the idle position, that slight loiter is to allow the system to "balance out" before returning to idle.
Damn, wasted my mod points to write this.