January 28, 2005

Curious George: Laptop batteries. I just replaced the Li-Ion battery in my laptop, but my tech-savvy wife says I can only expect a year of life at best. Is this pretty much on target? I remember that the factory battery (HP) did flake out after 18 months. Any experiences, ideas, or authoritative links on how to avert the annual battery toss?
  • My brother who works for Dell always says that you should keep your laptop plugged in unless it's absolutely necessary to run on battery power. He also said the least wearing method on the battery was to let the entire battery drain once you unplugged the laptop. Although personally, that doesn't make much sense to me.
  • My brother who works for Dell always says that you should keep your laptop plugged in unless it's absolutely necessary to run on battery power. If you use your laptop basically as a desktop (as I have done the last year) and never have it unplugged it will kill your battery pretty soon. You should drain it at least once a month fully and then recharge it again as soon as possible. Always full is not good and always empty is not good either. The battery needs some exercise. Just like I.
  • When keeping it plugged in remove the battery. I've heard this from a number of sources. Also second draining and recharging at least once a month. If running on battery, run down completely before charging back up. Also, battery life is unpredictable, I've seen them last 5 months and I've seen them last quite a few years. But these little steps will help.
  • Hmm... that's probably what ran down my first battery.... using it in a laptop used as a desktop.
  • The explanation I've heard is that batteries are rated for a certain number of full charged to empty cycles. If you keep one plugged in, it will charge up, stop charging, go down to 99% charged, then charge up again. So you waste battery life with small but repetitive chargings near the top of the cycle. You want to charge the battery to full, then remove the power source. Or if you aren't planning to use the battery in the near future, just take it out and leave it uncharged. And not leaving batteries plugged in after they are fully charged goes double for ipod batteries.
  • Putting a Li-ion battery through a full charge once a month is correct*. As for storage of a battery, it is not recommended to store at full charge, and for modern laptop batteries, never store with no charge in them. Modern batteries contain sensor chips, and if they are allowed to go completely dead, with no charge running to the sensor at all,it can be damn near impossible to get them to hold a charge again. The official recommendation for long-term storage is to discharge to 40-60% capacity first, then store it. Regardless, the total charge a Li-ion battery will take declines with age. There is no way around this, it is inherent in the way they work. Battery life begins declining from the moment they are charged for the first time (which is a good reason not to buy one from a store with slow inventory turnover--the battery is losing total charge capacity every day it sits on the shelf). Average lifespan for a battery nowadays is one to two years. *Note that this does not have to occur all at once, using 25% of the charge four different times will do the trick. Normal usage generally puts a laptop through at least one full cycle each month, unless you use your computer exclusively as a desktop machine.
  • The Li-ion in this HP machine is 4+ years old and running just fine.
  • My battery isn't charging/running properly - I get only about 20 min (without wireless card), and should be getting 2-3 hours. I realise I likely will have to buy a new one (it's only about 9 months old), but is there anything I can try to revive it?
  • jb I had a Dell, and the battery started acting like yours is, before the first year was out. I called Dell and it was a known issue. They sent a new one free of charge.
  • when i got my new iBook, which I love more than life itself and would kill for if it ever asked me ALL GLORY TO APPLE!!!, the instructions said to charge the battery all the way up and then use it until the computer was so drained it automatically went to sleep....judging by this and all the other literature on the subject, it seems to be a matter of stretching the two limits as much and as often as possible...the battery is essentially a big electron bag that hooks them onto all the lithium ions...think of it like a lung...if you only take tiny breaths (like the 100%-99% charging cycle) then you're not using the entire lung and it will eventually atrophy...although in this case its probably the chemicals getting used to having extra electrons in their area of the battery and using them to form permanent chemical (ie covalent) bonds to other molecules in the battery rather than the loose temporary (ie ionic) bonds that make these chemicals useful as a battery...the idea is to keep the whole thing in motion...which i highly reccomend...get a wifi card, go to the park, discard the notion that a computer is something that lives in one space that you have to sit down in front of, live a little.
  • IMHO, all the advice so far in this thread is generally correct, with the exception of the first comment, which I must humbly but strongly disagree with, and I was involved with a company where testing tens of thousands of batteries was a major part of our business. The shortest, most effective piece of battery advice for laptops owners - If you aren't using your laptop, unplug it. For most people's usage pattern, this generally avoids the constant charging problem, and ensures the battery gets some workout. If you leave your laptop constantly plugged in, the battery will be useless in under a year. Most companies no longer warranty laptop batteries for longer than 30-60 days because they cannot control usage. Trying to drain the battery completely roughly once a month is also very good advice. Pulling the battery out of the laptop completely is a tricky suggestion, and not generally a good idea. On top of battery storage issues, most laptops expect the battery to be part of the electrical circuit, even if it isn't capable of holding a charge. Some unusual and flakey behaviour can develop if the battery isn't there. The battery also acts as a minor buffer in the event of a power surge. None of these rules will save you if the laptop and/or battery is simply badly designed, as some are. I've known major manufacturer models where the batteries were notoriously short-lived, no matter what actions you took. C'est la vie.
  • Cool info, Nal. What do you think if I put my old battery in the laptop (plugged in all the time) and do the "monthly workout" on my new battery? When I need to be on-the-go I'd use my new battery. The old battery won't hold the computer even one second, but maybe it being there would be good enough.
  • That sounds generally fine, though I still don't like the 'plugged in all the time' idea, even if it is a worthless battery. I just think it's a bad habit to get into, forgetting to unplug the laptop. The battery storage issue is a bit tricky, as douggles already mentioned above. In my experience, it is rare for batteries to be negatively effected by long term storage, but it does happen with a few models. That business about sensor chips is true, there just aren't any hard and fast rules because it depends upon design and implementation. It is probably best to store a battery with some charge, but not a 100% charge. If you're very rarely on the go, I'd leave the new battery alone until you need it. Maybe pop it in the notebook for a cycle once every 6 months. One word of warning, when using an old, totally unchargeable battery in a notebook - try to make sure you never leave the notebook on before you unplug it - always turn it off before unplugging. Notebooks have a small secondary backup battery internally, that handles things like the clock function and power management, but it's a very small, limited battery. In some (poor) notebook designs, if the powered on notebook loses AC power with a 0% charge main battery inserted, the notebook will try to draw power to keep running off the small secondary battery. This can easily fuxxor the secondary battery if it continues for more than a few seconds, and means a $100-200 trip to the shop.
  • The first battery for my VAIO died about a month after its warranty expired. It was right after I had pulled it out and put it back in. I think it got a short, or something. After nine months, I finally got around to getting a new one. While I haven't specifically done the things recommended here, I don't usually leave it plugged in and there have been a few times where I put it in suspend-to-ram mode and forgotten about it. It's been working fine for about two years, now.
  • No matter what, if your battery is giving you trouble after less than a year, call and raise hell. You will most likely get a new one.
  • Check out the Battery University It's got the goods
  • As an aside, who knew that my hometown was the centre of the battery knowledge universe??? Vancouver Canada, Home of Battery University! Go B.U.!
  • Somewhat off topic, but still in the general vicinity: I travel with my laptop daily, and I tend to leave it on. Is this a bad idea? (I've googled some, but mostly find stuff on either telecommuting or plug adaptors and security.)
  • I travel with my laptop daily, and I tend to leave it on I assume you mean that you let it go into a low power mode, rather than turn it off. It's not inherently bad to travel this way, but it has some decided risks. 1) The notebook must be in 'hibernation mode', not just 'sleeping'. Sleep is generally used to refer to only partially powered down, and the hard drive is not necessarily parked properly for travelling, risking hard drive damage due to jostling. Hibernation is 99% powered down and safe to travel - the notebook just wakes up faster than if you had to wait to reboot. Check your manual and power management settings to determine when or how to put your notebook into hibernation as opposed to sleep. There's also often a button on the laptop that can be used to put it quickly into hibernation mode. 2) If you forget to power up and save your data before your battery runs out, you may likely lose whatever wasn't saved. This is the biggest reason I don't recommend this as a constant strategy. Talked to any number of people who forgot the notebook was still 'on' and also forgot they never saved that brilliant essay or memo they were writing. 3) Your operating system will become flakey. Many people I've known who became habituated to the hibernation strategy forgot that they were never giving Windows a chance to reboot and clean itself up. They'd be running the same Windows session for months, complaining to themselves about how flakey it was getting. Eventually Windows crashes in the middle of something important, and when they ask why, and you see that the Windows directoy is a mess and ask when they last rebooted, they look at you blankly and say "What?".
  • That Battery University page had some interesting technical information that was definitely useful, become I had to take serious issue with one statement. The question is often asked if one should disconnect the laptop from the main when not in use. With lithium-ion it does not matter. Once the battery is fully charged, no further charge is applied. This is absolutely not correct, as far as laptops go, as I and others mentioned above. Leaving your notebook plugged into AC for extended periods (weeks, months) is a sure recipe for a reduced or dead battery. Probably the blame lies with the laptop. Likely Lion batteries don't need to be charged anymore after reaching capacity, but it's bad laptop design that keeps trying to charge it. Still means you'll have a dead battery.
  • One thing that's interesting, that no one has mentioned here, is that rechargable batteries (Lithium Ion in particular) have a memory, and that's the reason they lose the ability to charge. A battery, if not discharged all the way, will "remember" that there's some charge in there, and not recharge that part. The memory of what isn't used will obviously be only a fraction of the amount not recharged, but over time this unrecharged part will accumulate, shortening the overall duration of use possible (or decreasing the total amount of charge that the battery can hold). That's why it's good to drain it as far as it can go before recharging. Think of it accumulating an internal crust that has to be broken up by discharging, and then remember to run until your computer puts itself to sleep.
  • My little cheapo HP Pavilion came with a battery optimization tool. Once every two months or so it pops up and asks me if I want to check the battery. After a short test, it fully discharges and then recharges the battery for me. I don't know if there's a Dell or freebie version out there that does the same thing, but after reading this thread I'm glad that I started using the utility. So far (nearly a year and a half now) the battery is doing fine. I do generally keep it plugged in, hibernate it when I go home for the day, power it completely down and reboot around once a week or so to clear the memory threads. Once or twice a week I take it to an alternate office and generally run off the battery (unless the power is already low from running it on battery over the weekend). I never gave much thought to the battery life, though. One tip I got from a friend - If you get a laptop somewhere like Best Buy, think about the extended warranty they offer. A salesperson told one of my colleagues that the only real reason to get the warranty was the battery - Best Buy gives her a new one once a year if she complains about the lifespan of the old one. She now has two batteries for her Sony; the original it came with, and the replacement Best Buy ordered for her just a few months ago. Not sure about how well this will work everywhere, but she was pretty happy with the outcome. (I also find it weird that I'm talking positively about buying anything at Best Buy, and an extended warranty to boot... did I wake up in Bizarro World?)
  • I'm rather amazed that Best Buy warranties the battery for any reasonable amount of money. Warranties in the IT industry, especially extended ones, standardly exclude the battery. Perhaps not enough people take advantage of that clause, so they can still make money on most of the warranties sold.
  • That's why it's good to drain it as far as it can go before recharging. But in practice this is limited by the laptop settings. For example on my laptop under Settings > Power Management > Alarms it is preconfigured to warn me when the battery drops to 10%, then auto-hibernate when it gets to 3%. Does this mean I should disable auto-hibernation and just let it run until the OS winks out?
  • Does this mean I should disable auto-hibernation and just let it run until the OS winks out? No. Lion batteries don't suffer from the type of memory effect people are used to with prior battery tech, so draining right to the last drop isn't as important. Further, your Lion battery may not charge properly after being absolutely drained - it might end up dead. Depends on the design, it's not predictable. Just drain most of it; whatever the settings make it easy to do. A few laptops might come with specific utilities, ala Live Frogs above, that deep discharge the battery and then re-charge it, but this is a special technique, carefully controlled by the software. Requires that the laptop design support it, and the manufacturer bothered to write the utility.
  • Dell's warranty will cover the battery for a full year (depending on the warranty probably, YMMV). My university has a contract with them and I put in work orders all the time (although it usually seems the batteries like to die about a month after the deadline to replace). The standard warranty here is Next Business Day service. Just a quick FYI.
  • Your old battery should be recycled. Electronics batteries are full of toxic chemicals. You can take it to stores listed on this site.