Microsoft Looking Into Windows 7 Battery Failures 206
Jared writes "Microsoft says it is investigating reports of notebooks with poor battery life with Windows 7, as first reported by users on Microsoft TechNet. These users claim their batteries were working just fine under Windows XP and/or Windows Vista, and others are saying that battery problems occur on their new Windows 7 PCs. Under Win7, certain machines spit out the following warning message: 'Consider replacing your battery. There is a problem with your battery, so your computer might shut down suddenly.' The warning is normally issued after using the computer's BIOS to determine whether a battery needs replacement, but in this case it appears the operating system and not the battery is the problem. These customers say their PC's battery life is noticeably lower, with some going as far as to say that it has become completely unusable after a few weeks. To make matters worse, others are reporting that downgrading to an earlier version of Windows doesn't fix the problem."
Re:My battery died (Score:2, Informative)
Re:Not experience this (Score:4, Informative)
Software controls how batteries are used/discharged.
http://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface [wikipedia.org]
Re:My battery died (Score:3, Informative)
Within a month the battery went from 90% to 3% and did an emergency hibernate.
Wow! That's quite the battery capacity you have there...
In all seriousness though, I've been using Win 7 since the week of release. My laptop battery is approximately a year old. I've had no problems with it whatsoever.
Happens in other OSes, too. (Score:1, Informative)
Hard to pin this down. (Score:5, Informative)
This is one of those things that's really hard to pin down.
LiON batteries -- what's used in most laptops and netbooks now -- have different kind of failures and limits from the older NiCD and so on. Aside from the catastrophic failures that made the news, what happens with LiON is that there are a limited number of charge cycles per cell no matter what you do. The cells generally go around 300 charge cycles before their capacity drops to about half. The controller in the batteries (which prevents them from just bursting in flames all the time) senses this and reports it back to the os.
The result is that when you upgrade the machine, you've already had it a long while and you're not far from that day when suddenly you notice your capacity has dropped to about half and you'd better replace the battery. Your cruising along at 60% then a minute later you're getting the warning that you're out of battery -- one or more cells is no good anymore.
To test this, you'd have to buy a new battery first and then compare life cycles.
btw: Lots of theories about how to make them last longer -- most of the actual experts say to try to keep it at around 40% if you're going to store it and not use it, otherwise just use the machine. The controller won't allow it to overcharge an they have no "memory" per se.
Re:Bullshit (Score:5, Informative)
Lithium Ion batteries do lose their maximum charge over time, that's a fact of physics. How much charge they lose depends on temperature and how much they're charged up.
http://www.batteryuniversity.com/parttwo-34.htm [batteryuniversity.com]
Re:explains my old Dell Inspiron 6000 (Score:3, Informative)
flash is also a big culprit. i've noticed that surfing facebook i get barely 90 minutes of battery life when i should have 3 hours. tried it by surfing non-flash sites and my battery life improved
depends.. (Score:3, Informative)
If you wanted to play the odds on best possible result -- he should use it tll it hits about 45% and then plug the laptop in and remove the battery, putting it on the shelf until he needs it.
The problems with that are
1. There's no battery in the machine, and it's really easy to pull the cord out the back of a laptop -- and its not really much of a laptop without a battery, is it?
2. The battery won't store charge indefinitely, so he's got to plug it in once in a while and make sure to keep that charge up around 40-50%
3. When he does need the battery, it hasn't got much charge in it so he's got to plan an hour or two ahead of time.
To me, I'd go with the "just use the damn thing" approach, and after a year or two just buy another hundred dollar battery.
For what it's worth, these guys were extremely helpful to me when I looked into this stuff and I've found them good to deal with (http://www.atbatt.com/). They also donate large numbers of 9v batteries to fire departments to give to people with smoke detectors, so I consider that worth some karma points.
Re:There is some kind of battery black magic (Score:2, Informative)
Once the battery is full, either unplug the computer from the wall and use only the battery, or take the battery out and use only the AC power.
Re:There is some kind of battery black magic (Score:3, Informative)
what you're saying has minimal significance on new laptops. Most new ones are a-okay with having the battery in and plugged in. They don't just blow an extra recharge cycle when it's plugged unless the battery is below the automated (or user set) threshold to recharge the battery. Example: Thinkpads do that. I've had mine cycle maybe 15 times over the course of a year, since it's plugged in most of the time anyway.
Batteries do discharge over time, so if you always keep it out when plugged in and forget, it's equally likely you won't remember to charge it for when it's needed.
Re:My battery died (Score:3, Informative)
Re:My battery died (Score:3, Informative)
Your two year-old laptop battery dies, and the first place you go is to blame the operating system?
You say that like a two-year-old battery is some kind of relic. I've never had a laptop battery become unusable in less than three years.
This happened to me when OS X was new (Score:4, Informative)
When OS X 10.0 beta first came out, it was so much nicer to use than 9 (just being able to wake from sleep in less than 10 seconds was enough alone) that I permanently switched over to it on my G3 Powerbook (Pismo model). However, that being the "previous" model at the time (I bought one of the last ones), they didn't have the power management working right, and it used up the battery noticeably more when in sleep. But that wasn't the big problem.
In the last month before the initial one-year warranty was expiring, I was running it off of battery. When the battery got down to 75%, it suddenly went to 1%. I thought it was a glitch or something. After that, the battery only started crashing sooner. At that time, due to the model being out of sale for a year, Apple (apparently) stopping production of replacement batteries (a really stupid idea right there), and (presumably) other people having their batteries die at the same time, getting a new battery was like pulling teeth... from an elephant.
This illustrates one of the failure modes with LiIon batteries. When they wear out, they will charge to 100%, but crash during the discharge cycle. Part of the problem was that Apple had their laptops topping off the batteries whenever not at 100% (later on, Apple made a change so as not to top it off when already at 95% of better), and part of the problem was that the incomplete power-down during sleep caused the battery to go through cycles faster.
Also, LiIon batteries have a shelf life of a couple of years even if not used. It's possible that some of these people might have had an older laptop, but the summary specifically mentions new W7 laptops, and Windows computers are usually traded up more often than Macs. But I'm sort of surprised that the BIOS wouldn't be handling the power management exactly the same whether XP or 7 was used.
Re:My battery died (Score:2, Informative)
Re:Not experience this (Score:3, Informative)
Re:There is some kind of battery black magic (Score:1, Informative)
I work for a company that sells laptop batteries and this is exactly what happens. All Li-ion batteries degrade from the moment that they are made, however the process is greatly accelerated by Heat & Charge Level. Using a laptop as a desktop computer keeps the battery at 100% charge and cooks it all day long. This stress can kill batteries in under a year.
The chips in the batteries store information on each charge/discharge cycle. As a battery wears the maximum capacity will decrease. If the battery is cycled on a regular basis, the chip will collect current data and re-calculate the percentages. If a battery is not cycled, the battery will assume that the maximum capacity based upon the last data that was collected. This will give a false percentage reading and will make the charge level drop out quickly.
Users incorrectly believe that by keeping the battery fully charged and never using it will preserve the battery. When they finally go on a trip 9 months later and try to use the battery it will fail on them and they do not know why. The #1 thing out of every customer's mouth is "but I never used the battery".
My take on the MS issue is that it is a combination of a few models with buggy ACPI data and also some just bad batteries. ACPI should report the battery's design capacity as well as the current capacity level. The ratio of the current capacity to the design capacity is called the State Of Health (SOH) and it represents the amount of wear on the battery. For example if your 6600mAh battery only charges to 3300mAh then your battery is 50% worn out.
In most OSs they only care about the relative state of charge (RSOC) to show you the charge percent. In some new OS (I am assuming W7), the OS tries to compute the SOH to let you know if your battery is bad. The problem is that many laptops do not correctly report the ACPI battery data. If the OS or the BIOS mis-report or mis-interpret the ACPI data then this feature can incorrectly report that your battery is bad. If you run Linux you can see this data in /proc/ACPI/BAT0/info. Most laptops that I have checked will mis-report some of this information.
Some of the reports are likely due to these false positives. These should be fixed by a tweak to the BIOS to allow W7 to properly interpret the ACPI data. The rest are most likely just bad batteries.
Same Here (Score:3, Informative)
Opposite experience (Score:2, Informative)
Re:My battery died (Score:4, Informative)
Linux is perfect. You just don't know how to configure it.