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."
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.
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.
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).
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.
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
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)
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.
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.