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Mac Forum / General / Portable Macs / January 2005Sudden Battery Failure - PowerBook/iBook
Since April-May of '04, many Apple portable users have experienced "sudden battery failure". My battery was 18 months old and went from 3+ (4+?) hours service to 30 minutes. My iBook suddenly falls asleep without the usual low-power warning. I associate the sudden failure to a system software update, one that probably included Battery Update 1.1. (Most power management controllers (chips) on such batteries are "writeable".) A graphical representation of my battery discharge/charge cycle can be seen at <http://members.core.com/~terrye/Xbattery.jpg> The number of complaints seem to be rising. Apple (PowerBook and iBook) -> Support -> Discussions are full of people experiencing the same problem, but Apple doesn't respond well, or acknowledge a problem. See an example of the discussion at <http://discussions.info.apple.com/webx?14@981.N4VAaH6PLKt.1@.689b7c01> Additional legions have expressed their alarm at MacFixit and MacInTouch. Age of the battery doesn't seem to be a factor, as an equal number of failed batteries seem to be under one year old and fall under Apple's warranty..., and are quikly replaced by Apple. (AppleCare, AFAIK, doesn't cover batteries.) Gruntle is being dissed.... > Since April-May of '04, many Apple portable users have experienced > "sudden battery failure". My battery was 18 months old and went from 3+ [quoted text clipped - 7 lines] > A graphical representation of my battery discharge/charge cycle can be > seen at <http://members.core.com/~terrye/Xbattery.jpg> Given the age of the battery, it looks to me like it's just worn out. These things happen. Live with it or get a new one.  SignatureTom "Tom" Harrington Macaroni, Automated System Maintenance for Mac OS X. Version 2.0: Delocalize, Repair Permissions, lots more. See http://www.atomicbird.com/ > My battery was 18 months old and went from 3+ > (4+?) hours service to 30 minutes. My iBook suddenly falls asleep > without the usual low-power warning. > A graphical representation of my battery discharge/charge cycle can be > seen at <http://members.core.com/~terrye/Xbattery.jpg> Can you tell us about your battery calibration history? How many hours (in total) have you run on battery in those 18 months that you've had it? (what's your best estimate?) (Looks like your battery could benefit from trickle calibration.) What capacity does your battery think it has? (in terminal, unplugged, run /usr/sbin/ioreg -p IODeviceTree -n battery -w 0 | grep yI Probably the best thing after 18 month is a new battery. And calibrating your old battery and using it as a reserve. I strongly recommend *trickle* discharge calibration, and in general, avoiding sudden (heavy) loads while on battery. -- Peter > Can you tell us about your battery calibration history? > How many hours (in total) have you run on battery in those > 18 months that you've had it? Same thing happened to my Pismo battery. After looking closely at and measuring each the battery cells that make up the battery pack (I'm skilled in the electronic arts), I determined that one of the cells had died, which reduces the ability of the pack to handle any load. It's dead. I, too, thought that a change to OS X (or some version of it) had been responsible for the battery's demise. Now I mark it up to coincidence. Batteries (ie, NiCd,NiMH, and LiIon) don't like high temperatures and long-time charging. But for laptop batteries that's all they get: stuffed inside a battery compartment, mostly plugged into the AC adapter. All batteries of this kind have a limited life, measured not in months, but charge cycles. Plugging in the charger = one charge cycle. If you go to work or school and plug in again, that's 2 cycles per day, at least. Times 365 days ~ 700 cycles. Over 18 months, this usage approaches the general (*very* general) maximum of 1000 cycles. So, unfortunately, laptop batteries, because of their designed usage, suffer short life, in general. How to extend your battery's life? When it's charged, take it out and leave it on the shelf until you *need* to be in battery mode, then insert it in your laptop. Not very practical, is it? Good luck, SignaturePlease, no "Go Google this" replies. I wouldn't ask a question here if I hadn't done that already. DaveC me@privacy.net This is an invalid return address Please reply in the news group > > Can you tell us about your battery calibration history? > > How many hours (in total) have you run on battery in those [quoted text clipped - 14 lines] > All batteries of this kind have a limited life, measured not in months, but > charge cycles. Plugging in the charger = one charge cycle. Is this the case? I had thought that the charge controller turned off charging current when the battery was full, and would only turn it back on after the battery dropped below X%. Further I was under the impression that Li-chemistry batteries measured partial charges as partial cycles, for the purpose of counting cycle life. I might very well be wrong about either or both of these beliefs, but neither strikes me as unlikely. Anyone know for sure or will I have to go over to sci.chem.electrochem.battery? SignatureLater. johajohn@indianahoosiers.edu Let 'indiana' be a 'noln', and 'hoosiers' be a 'solkk'. Leave only the 'noln' and .edu after the @ to reply . > Is this the case? I had thought that the charge controller turned off > charging current when the battery was full, and would only turn it back > on after the battery dropped below X%. Let's say this is so. Then the charge controller will turn the charger on again, then off, then on... each one a charge cycle. On top of that, you unplug and reconnect the AC adapter as you need to, adding more charge cycles to the count. > Further I was under the > impression that Li-chemistry batteries measured partial charges as > partial cycles, for the purpose of counting cycle life. Batteries don't "count" anything. It's the charge voltage applied to the cell that shortens its life by a tad, each time. Just like bending plastic, or metal, you can do it many times, but eventually it breaks. > I might very well be wrong about either or both of these beliefs, but > neither strikes me as unlikely. > > Anyone know for sure or will I have to go over to > sci.chem.electrochem.battery? That's where I got my questions answered. SignaturePlease, no "Go Google this" replies. I wouldn't ask a question here if I hadn't done that already. DaveC me@privacy.net This is an invalid return address Please reply in the news group > > Is this the case? I had thought that the charge controller turned off > > charging current when the battery was full, and would only turn it back [quoted text clipped - 12 lines] > that shortens its life by a tad, each time. Just like bending plastic, or > metal, you can do it many times, but eventually it breaks. If this analogy is good, then partial cycles 'count' as partial cycles (WRT 'using up' battery life). If I bend a paper clip, it matters both how many times I bend the metal and how _far_ I bend it. It's immaterial though. This list has been through countless battery life threads, and I used to hang out on sci.chem.electrochem.battery myself. I could look up the stuff and find out whether/how far wrong I am, but I don't have the time. I bow to your advice. SignatureLater. johajohn@indianahoosiers.edu Let 'indiana' be a 'noln', and 'hoosiers' be a 'solkk'. Leave only the 'noln' and .edu after the @ to reply . > It's immaterial though. This list has been through countless battery > life threads, and I used to hang out on sci.chem.electrochem.battery > myself. I could look up the stuff and find out whether/how far wrong I > am ... or I am : -) , but I don't have the time. I bow to your advice. I don't claim expertise, but I asked enough questions to satisfy my own need to find some rules to live by. This is what I came up with. YMMV. Take care, SignaturePlease, no "Go Google this" replies. I wouldn't ask a question here if I hadn't done that already. DaveC me@privacy.net This is an invalid return address Please reply in the news group > What capacity does your battery think it has? > (in terminal, unplugged, run > > /usr/sbin/ioreg -p IODeviceTree -n battery -w 0 | grep yI Measuring at roughly five minuter intervals, while writiing, browsing with 1/2 brightness, with four or five applications running and Airport active, I get the following values: 100% - "Capacity"=3172,"Amperage"=1087,"Current"=3126,"Voltage"=11847 98% - "Capacity"=3172,"Amperage"=1053,"Current"=3113,"Voltage"=11787 95% - "Capacity"=3172,"Amperage"=982,"Current"=3047,"Voltage"=11410 91% - "Capacity"=3172,"Amperage"=1053,"Current"=2895,"Voltage"=11073 86% - "Capacity"=3172,"Amperage"=1029,"Current"=2745,"Voltage"=10993 80% - "Capacity"=3172,"Amperage"=1085,"Current"=2564,"Voltage"=10795 77% - "Capacity"=3172,"Amperage"=1131,"Current"=2463,"Voltage"=10696 72% - "Capacity"=3172,"Amperage"=1107,"Current"=2290,"Voltage"=10577 68% - "Capacity"=3172,"Amperage"=18446744073709550491,"Current"=2,"Voltage"=11 410 ...and these are the readings immediately after it wakes from suddenly falling asleep...ooops!... on AC power. With a 1% charge, I get the following readings (and a normal low-battery warning): "Capacity"=3172,"Amperage"=1200,"Current"=43,"Voltage"=12065 This is interesting, I've been running on "0%" charge for almost five minutes and after the "normal" low-battery warning. (In the last few weeks, since I've been "working" on this battery, I've seen an almost cartoonish "low battery warning", but it literally flashes across the screen as the iBook falls to sleep. Make that ten minutes' usage on 0% in the Menu Bar Battery Status...and that's all! (Now, before the computer would fall asleep, Internet Connect came forward and tried to disconnect. Today, I've been trying to get the dial-up PPP configured without resounding success. (I get dropped fairly regularly.) But, Internet Connect has a significant problem "disconnecting".) My general usage pattern is to either use it at a desk, on charge, or run it on the battery when I take it in front of the TV. So, I would run it off the battery two-three hours a day, often running it until the battery was out of charge. I don't watch DVDs, so most usage is browsing, writing or "figuring". On the infrequent occasion I take it someplace, I usually use the battery until it runs down, then connect the power adapter. I looked around the web and found batteryuniversity.com to be a reasonable source of general information about Li-Ion batteries. They maintain that partial charge-cycles are accumulated to comprise a single charge-cycle. Many sources assert that Li-Ion batteries are good for 1000 charge-cycles. Considering 300 charge-cycles per year, under normal usage, a laptop Li-Ion battery should last 2-3 years. (Maybe I got a stale or used battery from Apple. The first battery never held a charge and they gave me a new battery about a year ago. This battery has been in this sad state almost six months.) I wonder if the Cadex SM2+ would help me understand this battery's "state of health" and "state of charge"? <http://www.cadex.com/prod_chargers_sm.asp> Would you consider the following routine to be a "trickle" dischage calibration? From MacInTouch: > From: Swift > Subject: Powerbook G4 Battery Resuscitation [quoted text clipped - 13 lines] > a "power hungry" 12 volt appliance because the internal > power manager will not let it be drained too quickly.) -te- (don't use the email address -- i'm on the verge of closing the account) "Trickle Calibration" is my invention. Google it (on this newsgroup). I have a program to assist the process, but i'm on the verge of rewriting in in Python ... (if you really want I'll send you the current (imperfect) zsh script -- peter at dancing dot org ) Do this: 1. Fully charge 2. set it to never sleep (on battery and on AC) 3. for best results, restart, to make sure no apps are running 4. turn off airport, etc. unplug everything, set brightness to 1/16 pull the plug and leave it alone (turn brightness right off). wait for it to COMA-SLEEP plug in and let it charge, to full. (you can use it while it's charging.) Note: shortly after you plug it in, the CAPACITY will be adjusted. N.B: you may notice that it drops from, say, 70% full to 0. Then, when charging, it will go from 0-30 and then jump to 100%. After another trickle calibration it the "missing" range may shrink. You will probably end up with an actual capacity of 1700 rather that 3100. (New was 4000). N.B.: When on battery, keep the load as low as possible, and avoid sudden load surges. Keep airport off when not in use, and try to get by with 1/16 display brightness. Try not to use optical drive. Please report your results. -- Peter >> What capacity does your battery think it has? >> (in terminal, unplugged, run [quoted text clipped - 93 lines] > > -te- > "Trickle Calibration" is my invention. [...] > [quoted text clipped - 13 lines] > > Note: shortly after you plug it in, the CAPACITY will be adjusted. Why do you (and so many others) think that runnig the computer at an unrealistic minimal load will calibrate the battery (or power manager) better than using it for normal work? I think that the latter will actually be preferable in order to allow for sensible estimation of capacity and runtime. The important point is just to run it all the way down from 100% to 0% and further, i.e. until it automatically goes into sleep mode, and then recharge it immediately. </Niels> >> "Trickle Calibration" is my invention. [...] > Why do you (and so many others) think that runnig the computer at an > unrealistic minimal load will calibrate the battery (or power manager) [quoted text clipped - 3 lines] > down from 100% to 0% and further, i.e. until it automatically goes into > sleep mode, and then recharge it immediately. To be sure, not only do I recommend trickle calibration, but I also recommend that one reduces the load, and especially (sudden) load increases, while on battery. *If* one wishes to maximize the runtime-on-battery, of course. If one's "normal" involves high power consumption and load surges, then one will accept a much shorter runtime-on-battery, and one will simply buy a new battery (perhaps after 1 year, rather than 3 or 4). A load surge (turning on optical drive and airport, while turning display brightness to maximum) may induce (premature) coma-sleep, when otherwise one might have been able to continue on battery for another hour or two. This becomes even more important as the battery ages, since the internal resistance doubles about every 85 discharge cycles, so, after daily battery drain use for a year, the battery's internal resistance may have increased tenfold. Higher resistance causes greater voltage drop, and when the minimal voltage is reached, it's coma-sleep time. So, trickle calibration will give the best estimate of the capacity since it won't terminate prematurely, and minimal, surge-free usage while on battery will keep you going the longest since you won't be forced into coma-sleep prematurely. Same usage pattern. It's just a different "normal" :-) Of course, eventually the battery's internal resistance will not be able to stand much exertion any more. BTW, premature recalibration due to heavy load will result in underestimated capacity, which then gives one a reduced "fill-up", and so on. So, you will see a pattern of discharge from 100-70%, then drop to 0%, followed by a charge of 0-30%, then jump to 100% With trickle-calibration, that missing middle (30-70%) may shrink away. The new improved (TI) software will keep track better and the missing middle won't happen any more. Of course there will still be the aging, with its ever increasing internal resistance. My program tries to give a better estimate of how much battery charge is actually left. It avoids the sudden "surprise". (And gives you a log). But the next generation firmware will make such things less necessary: http://focus.ti.com/docs/prod/folders/print/bq20z80.html -- Peter > Batteries (ie, NiCd,NiMH, and LiIon) don't like high temperatures and > long-time charging. But for laptop batteries that's all they get: stuffed > inside a battery compartment, mostly plugged into the AC adapter. But when plugged into the adapter they charge up to full and then are put on a float charge usually. This compensates for self discharge without significantly heating the battery (beyond ambient). > All batteries of this kind have a limited life, measured not in months, but > charge cycles. Plugging in the charger = one charge cycle. If you go to work > or school and plug in again, that's 2 cycles per day, at least. Times 365 > days ~ 700 cycles. Over 18 months, this usage approaches the general (*very* > general) maximum of 1000 cycles. No, fully discharging the battery and recharging it is one charge cycle, not draining a few mWHrs and then charging it. Discharging it to 50%, charging it to 100% and then repeating this accounts for one charge cycle more or less, typically less. > So, unfortunately, laptop batteries, because of their designed usage, suffer > short life, in general. Getting two or three years out of a rechargeable battery is doing pretty good. Considering the high power load of a laptop they do quite well. The most important factor for extending the operating life of a battery is a good battery charger that will charge it to 100% without overcharging and to shut things down (sleep) when the battery gets discharged low enough. SignatureClark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" >> Batteries (ie, NiCd,NiMH, and LiIon) don't like high temperatures and >> long-time charging. But for laptop batteries that's all they get: stuffed >> inside a battery compartment, mostly plugged into the AC adapter. > But when plugged into the adapter they charge up to full and then are > put on a float charge usually. This compensates for self discharge > without significantly heating the battery (beyond ambient). NiCd batteries tolerate some float charge, NiMH tolerate less. LiIon batteries do not tolerate float charges at all. That is why charging circuits for LiIon batteries usually wait until several percent of the capacity is used before starting a "topping" charge. But in any case, float charges are used for lead acid and other batteries that tolerate overcharge better than any of these three technologies. >> All batteries of this kind have a limited life, measured not in months, but >> charge cycles. Plugging in the charger = one charge cycle. If you go to work >> or school and plug in again, that's 2 cycles per day, at least. Times 365 >> days ~ 700 cycles. Over 18 months, this usage approaches the general (*very* >> general) maximum of 1000 cycles. > No, fully discharging the battery and recharging it is one charge cycle, > not draining a few mWHrs and then charging it. Discharging it to 50%, > charging it to 100% and then repeating this accounts for one charge > cycle more or less, typically less. >> So, unfortunately, laptop batteries, because of their designed usage, suffer >> short life, in general. > Getting two or three years out of a rechargeable battery is doing pretty > good. Considering the high power load of a laptop they do quite well. > The most important factor for extending the operating life of a battery > is a good battery charger that will charge it to 100% without > overcharging and to shut things down (sleep) when the battery gets > discharged low enough. > "I'm a designated driver on the Information Super Highway" |
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