The past few weeks or so, there’s been a lot of interest in a supposed battery status report bug in Windows 7. After installing Windows 7, some users reported seeing “consider replacing your battery”-warnings in systems that appeared to be operating just fine on Windows XP or Vista. After extensive research, Steven Sinofsky has now explained on the Engineering 7 blog that the fault is not with Windows 7 – it really, really is your battery.
Posts all over the web – blogs, forums, articles – popped up, claiming that Windows 7 incorrectly marked batteries as in need of replacement, or, worse yet, that Windows 7 caused these batteries to fail. Microsoft has been investigating the issue, and they have come to the conclusion that Windows 7 is not at fault – those batteries really need to be replaced.
“To the very best of the collective ecosystem knowledge, Windows 7 is correctly warning batteries that are in fact failing and Windows 7 is neither incorrectly reporting on battery status nor in any way whatsoever causing batteries to reach this state,” Sinofsky writes on the Engineering 7 weblog, “In every case we have been able to identify the battery being reported on was in fact in need of recommended replacement.”
Microsoft has contacted customers who reported this problem, they went over customer service communications, discussed this issue with PC makers, and analysed telemetry data from Windows 7. “To date all such steps indicate that we do have customers seeing reports of battery health issues and in all cases we have investigated Windows 7 has simply accurately detected a failing battery,” Sinofsky writes.
Windows 7 makes use of built-in features of batteries that allow the battery health status to be read. “This is reported in absolute terms as Watt-hours (W-hr) power capacity,” Sinofsky explains, “Windows 7 then does a simple calculation to determine a percentage of degradation from the original design capacity. In Windows 7 we set a threshold of 60% degradation and in reading this Windows 7 reports the status to you.”
The key point here is this: this functionality was not part of Windows XP or Windows Vista. As such, people who think Windows 7 is causing the batteries to fail have it backwards; the battery was already in need of replacement, but XP nor Vista had the ability to report that to you.
In the blog post, Sinofsky gives detailed insights into the data used to come to the conclusion that Windows 7 is not at fault, and from that data, the conclusion is clear. Sorry folks, it’s time to go battery shopping.
Batteries degrade fast– The funny part is how people have known this for years. I’ve heard the complaints myself: “My battery used to run for 2 hours, and now it’s down to 20minutes.”
Oddly enough, the MS wording is “recommended replacement.”
As you can see from the comments, for some people, the very same battery that suddenly runs down to 20 minutes with Windows 7 still runs 60 minutes with XP or Vista on the same computer.
i tested it using the live image of fedora 12 on one of my hp laptops and windows 7 and fedora 12 said the same thing about the battery. thats enough proof for me…
So tiresome to see your laptop’s battery life slowly degrade over the years. And all of these “breakthroughs in battery technology” that keep popping up in the news never seem to amount to anything. Laptops are still using Li-ion batteries, right?
PS: “the battery was already in need of replacement, but XP nor Vista had the ability to report that to you.”
Shouldn’t that be “neither XP nor Vista”? http://en.wiktionary.org/wiki/nor#Conjunction
Hi,
Change costs money, which might cut into laptop manufacturer’s profit (especially as there’s no easy way for consumers to compare the life expectancy of laptop batteries, so improving this life expectancy probably won’t result in better sales). Doing nothing means the laptop manufacturers make more cash; either from replacement batteries or people upgrading the entire laptop earlier than they otherwise would.
Eventually, with enough research and technological breakthroughs, I’d expect batteries that die 2 weeks after the warranty expires (but I wouldn’t expect longer life)…
-Brendan
So tiresome to see your laptop’s battery life slowly degrade over the years. And all of these “breakthroughs in battery technology” that keep popping up in the news never seem to amount to anything. Laptops are still using Li-ion batteries, right?
Well, there has been lots of significant breakthroughs yes, like the Li-air technology which would both provide longer battery life AND longer discharge time. But you have to remember that even though they’ve found a way to do such things it takes several years to find a commercially viable way of producing the same effect. In the case of Li-air they have huge hurdles in front of them due to having to find a way to mass-produce the components needed and how to do it cheap.
I’d say that just hang in there; with all the advancements in battery life during the last year it should take 5-10 years before the new technology is finally mass-produced and brought to general populace. But when they finally arrive we’ll all be happier.
My battery needs to last long enough to get me from one outlet to another. My laptop is plugged in as often as possible.
Yes. I’ve PMd Thom with a pointer to that effect before, but he seems quite content to ignore it. I figured since his English is damn near perfect, he’d be happy to hear about and correct one of his few remaining problems
MamiyaOtaru posted…
What!?! And have people mistake him for a dirty American? What are you even saying? ;P
–bornagainpenguin
That’s actually really bad for the battery because the cells don’t complete the charge/recharge cycles. Then when you do suddenly need to start carrying the laptop around, the cells won’t “dig deep” and keep going. The circuitry does the wrong thing.
I think this is a side effect of Microsoft’s longstanding push for each OEM to write their own “drivers” for simple stupid things. There are motherboards out there that actually report different hardware settings to Windows than “generic Bios” and this is just another one. We’ve seen hard drive controller have “hidden codes”, “soft” sound cards, “soft” modems, and the list goes on. Microsoft finally felt the need to “fix” the bad hardware their older OSes allowed OEMS to hide for years, just like when they finally added a good wireless manager to Vista after the one in XP was a dog and OEMs pre-SP had to roll their own.
My point is that these things SHOULD be open hardware APIs, but their “just a little broken” so you need the “Windows X-version” drivers… that way each OEM can feel special, Microsoft can poke vendors like AMD-Intel and Nvidia-ATI against each other over petty details, instead of how good a computer allows the user to do tasks.
edit: You have to get the joke. Microsoft keeps it’s monopoly by being the only player that can sort out all of these little pieces. They pit chip manufacturers, computer makers, software writers, and users against each other so they’re so busy “stomping bugs” they can’t go anywhere else.
Edited 2010-02-12 05:34 UTC
From my experience, there is some perplexing magic about batteries. Sometimes they work full capacity and then all of a sudden start losing 20% a week and die. Some on the other hand outlast the laptop they came with.
Batteries are not solid state parts. Abuse of the battery during charge or discharge (including unknowingly using dirty power lines, and over-discharging it too often) will hurt its capacity and service life. Charging too often will hurt its capacity and service life. Leaving it stored with a full charge will hurt its capacity and service life. Lithium-based rechargeable cells also lose capacity from age, regardless of how they are used (yes, I’m giving Apple the evil eye, here).
To top all of that off, there are variations between each cell and each battery pack that cannot be discerned until it is well worn.
Commodity Lithium-based battery technology is pretty much bleeding edge science with penny pinching thrown in for good measure.
Reading the post, and it’s comments, there seem to be two quite separate issues people are complaining about. One is that W7 reports their battery as failing – well, that seems correct behavour, if this article is to be believed.
The other, though, is people reporting greatly reduced battery life after installing W7 – a fully-charged laptop might run for a couple of hours under XP, but less than half that under W7. That seems a bit more concerning…
Where is your citation?
After browsing multiple web sites the worst case I could find was around 20% less battery time under Win7, most showed neglible difference and one even found an increase.
Or it just means that according to the battery’s health reported back to the OS, it is “dead”, but Windows XP just ignored it while Windows 7 actually “listens” and shuts down properly.
Warning: rambling about batteries about to occur:
Battery health monitoring sensors can be pretty crappy sometimes – I’ve experienced a lot of inconsistent battery life meters – sometimes being able to disable an OS’s built-in auto-shutdown feature and gain a lot of extra time with the battery.
Careful playing this game though, as this can actually cause premature failure of individual cells in the battery. When one cell in a mult-cell battery pack is completely discharged, you can often continue using the pack as it’s still producing enough voltage to power your device. However, once a cell has discharged completely, continuing to run it in series with other cells will reverse-charge the cell which will eventually irreparably ruin it, making it a permanently-dead cell.
Proper battery health monitoring measures voltage levels and drop-rate along with temperature of the entire pack to detect irregularities and shut down the discharge or charge cycle completely.
Common premature failures of battery packs are caused by mismatched cells – cells that have different peak charge capacities. This causes a pack to only charge partially when one or more of the cells “peak”, leaving the remaining cells partially filled. Likewise, the cells with the least capacity will discharge first, and will start to reverse-charge causing more damage to them. Eventually, you end up with a 6-cell pack that only has 5 working cells… it will fail health monitoring tests.
There, sorry… just a long diatribe from someone who spent a lot of time learning about rechargeable batteries while messing with R/C cars
Ah the A-main battery dump with 10 seconds left….
TURN MARSHALL!!!!!!!
LOL, I can almost imagine a laptop screaming that just as it dies
that was true for nicd and pb cells
modern lithium cells already die when deep-discharged (less than ~3v)
as great as their capacity is, as sensible they are…
I can’t say I’ve seen a 50% decrease, but I’ve seen some issues where by Windows 7 will not get as much life out of a battery as XP or Linux. I’ve seen about a 15% reduction on some machines, and I’m 99.99% sure that it wasn’t due to an unhealthy battery. I suspect, personally, it was the result of badly-behaved acpi bios coupled with no acpi drivers for win 7 on those machines, while XP and Linux both had support for all the ACPI features once configured. As is typical with Windows, the majority of problems aren’t caused by Windows itself but by incompatible and/or poorly-written drivers. Other than Malware, drivers are the number one problem I see when dealing with Windows and I suspect it is mostly that to blame for reduced battery life under 7 on a lot of machines.
I’m fairly certain that, unless the manufacturer of your BIOS is an idiot, ACPI-based power management shouldn’t really require any special drivers. I mean, that’s sort of the whole point of standardizing that isn’t it?
I’ve read that some BIOS will serve up different ACPI tables based on the OS they detect is running. A lot of retarded manufacturers have hardcoded their ACPI tables to spit out something different if they don’t detect Windows XP… perhaps that is what you’re referring to?
I’ve rarely installed the crapware “battery/power management” software that comes with a laptop – more often than not it provides little benefit over the stock features, other than providing some fancy UI and some extra software-based “profile” features for those who like to fiddle.
Edit: OK, I suppose some of those crapware programs probably replace the “missing” functionality from Windows XP – but from what I read, Windows 7 supposedly fills that gap again.
Edited 2010-02-09 03:43 UTC
ACPI is standardized in theory, but hard-coded tables are only one of the issues. Some ACPI bioses behave badly, either not responding to certain functions or returning bad information. Typically these machines come with Windows drivers that compensate for it. I’m not talking about the crapware power management utilities but the driver component itself. Also, just because a system has ACPI bios doesn’t mean you’re machine will adjust itself (scale back the CPU and/or FSB when not needed, etc). This, too, typically requires a driver or utility as the os itself doesn’t often handle it. In the case of Windows this is taken care of by installing drivers, in the case of Linux and other *NIX oses you need to configure the CPU frequency scaling and FSB scaling yourself if there’s no utility to do it for your machine. ACPI is a standard at least on paper, but it merely provides the os a way to communicate with the ACPI bios and through there control the system’s power management. It doesn’t do much on its own. This is in contrast to APM which was used before ACPI became commonplace, which handled a lot in the bios itself and much less through the os. Having dealt with both of them, I’d say I prefer ACPI (even buggy ACPI) over APM.
Fair enough… this was one major lacking feature in XP (likely present in W7) – I do recall installing “Intel Speedstep” on several of my laptops in order to reduce CPU performance.
That may be, but there are tons of HP and Compaq notebooks out there that might qualify for having idiotic BIOSes, and require special drivers, often only available for Windows XP (and, often, even APM won’t work, in Linux).
It is pretty ironic, yet not surprising, that one of the top problems with Windows 7 is lack of drivers, since that is also the top problem in “alternative” OSes. I wonder when these hardware manufacturers are going to get it through their thick skulls that producing hardware and drivers which only works with Windows XP is stupid. They should at least document how there crappy hardware works so other people can write proper drivers.
My Acer Aspire 1 D150 gets same battery life in everything. Around 5 hours of battery life in WinXP, WIn7, and Ubuntu Netbook Remix.
Since we are on the battery topic, I am kind of confused about something.
Is it OK to have your laptop while the battery is inside permanently plugged in to the power? I mean at work, we have the laptops permanently plugged in while the battery is in the laptop. Don’t we over charge and destroy the cells? Someone told me it’s worse to have it charged every two hours than having it plugged in permanently. Is this true? I think once it reaches 100% it no longer charges but I am not sure.
Edited 2010-02-09 08:51 UTC
That’s one thing I too have been wondering about. Logic says that the laptop would be smart enough to just stop charging once the batteries are at 100% and would let them sit idle until the laptop is unplugged…but then again, many vendors are known to just go the easiest route whenever possible and I’ve actually had a laptop which would start charging the batteries every 2 minutes when they dropped to 99%.
I’ve heard mixed messages regarding that; I was worried because I do the same with my laptop – I tend to have it plugged in for long periods of time. On one forum I was told that it is good to use the battery as much as you can to ‘exercise’ the battery. Another forum said that it doesn’t matter, its all voodoo to claim it needs to be exercised. For me I am conscious about looking after my hardware so even as someone who is pretty knowledgeable about computers – I am confused as to what I am supposed to do.
Hmm I only just started leaving my personal laptop permanently plugged about a 3/4 days ago. Perhaps there is an expert here on OSAlert that knows the answer to this question?
Update: There are mixed responses everywhere. since there are so many, I picked the one I like
http://tech.yahoo.com/blog/null/67132
Edited 2010-02-09 10:13 UTC
Batteries are designed for being in computers on AC. So they are okay.
They do however lose capacity by being a full charge and by being hot (laptops on AC gets hotter than when on battery).
So if possibly you might be able to extend their lifetime by discharging them partially and removing them and storing them somewhere cold and dark. On the other hand, then they are not readily available when you do need battery in your laptop. Better just by a new battery every two years.
That seems to be the case with battery tech in general. E.g. people have told me that you should ALWAYS fully-discharge your laptop battery before recharging – and others have told me the exact opposite (that you should NEVER fully-discharge a laptop battery).
The best (or most plausible-sounding) explanation I’ve heard is from a friend who studied electrical engineering: fully-discharging means the battery will hold a charge longer, at the expense of the overall lifespan of the battery. While *never* fully-discharging means the battery will have a longer lifespan, at the expense of how long it will hold a charge.
I find that this one is better
http://www.friedbeef.com/top-15-ways-to-extend-your-laptop-battery-…
First link has <a hef=”… instead of <a href=”… which means it can’t be clicked on
Yes, <a hef=”…” will take you to playboy.com.