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500 Charge Cycles in 11 months
- Thread starter Cooee!
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Just for the record:
Lead Acid batteries are an exception, and degrade relatively quickly if unused.
The real issue here is that I'm pretty sure a certain number of charge cycles and higher will invalidate the warranty for the battery and you'll be left having to shell out to replace it should you ever have a problem with it.
Otherwise it shouldn't be an issue...
Otherwise it shouldn't be an issue...
I've honestly had a lot of trouble following this. Every laptop I had prior to my MacBook I had to make sure I unplugged it right when it got to 100%, so now it's just a bad habit.
I leave it plugged in when I'm on the computer the most (during the night). When my Air is idle I also leave it plugged in so it can do things in the background while I'm gone.
When on the go, or just hanging around the house without a charger, I generally try to keep my battery between 20 to 75%. That's worked the best overall. I'm at about 170 charge cycles and I got my MBA in May, which I'm not sure is that great, but hey, I use the heck out of this thing.
A new battery will indicate if there's a problem as far as I know. If it's above a reasonable number of charge cycles, apple won't replace it; it's not a hefty price, though. If the battery says it needs to be replaced (this is in system info) and you're below 400 or 300 cycles, they will replace it. It's very situational.
Anyone have any other tips for optimizing battery life? I want to preserve this battery for at least another year.
I leave it plugged in when I'm on the computer the most (during the night). When my Air is idle I also leave it plugged in so it can do things in the background while I'm gone.
When on the go, or just hanging around the house without a charger, I generally try to keep my battery between 20 to 75%. That's worked the best overall. I'm at about 170 charge cycles and I got my MBA in May, which I'm not sure is that great, but hey, I use the heck out of this thing.
A new battery will indicate if there's a problem as far as I know. If it's above a reasonable number of charge cycles, apple won't replace it; it's not a hefty price, though. If the battery says it needs to be replaced (this is in system info) and you're below 400 or 300 cycles, they will replace it. It's very situational.
Anyone have any other tips for optimizing battery life? I want to preserve this battery for at least another year.
Yes, it does. ANY discharging of the battery causes damage. The deeper the discharge, the more damage. Hence why it's best to keep it topped up.
I suppose if you equate normal wear with damage then that is true. Damage to me means degradation to a system beyond normal wear through expected usage.
You damage a battery by exposing it to extreme heat or cold, puncturing it, applying extreme pressure, etc. Putting an iPhone on the charger in a hot car will damage the battery, allowing the battery to freeze will damage it. Keeping the batteries Apple uses 100% charged all the time will damage them. Using them normally whether to 80% charge or 1% charge routinely will make just about 0% difference in the charge cycles and calendar lifespan.
I just went through a MacBook battery issue with a friend's laptop this past weekend because the trackpad wasn't working. We took it to the Apple store, and the staff person asked if it was left plugged in for long periods of time... which was in fact the case. He indicated the battery swelled as a result. I'll admit my first reaction was that it sounded like a lame excuse for a defective battery (though the battery was several years old). Rather than stick my head in the sand, I did some research... and turns out to be true.
I know a lot of the following has already been stated here, but one more time... check out Apple's support site on battery usage for yourself. Those are the guidelines that Apple recommends. And no, they don't have any hidden agenda to sell more batteries that way.
The battery is designed to be charged and discharged on a regular basis. It's okay to leave it plugged in most of the time, but it should be charged and discharged at least once per month to keep the electrons flowing. Same with "shallow charges" - perfectly fine, but should be discharged more fully on occasion.
If you're going to store it for a long period of time, you should discharge to about 50% before powering it off. Leaving the battery fully charged for months at a time can damage the battery. Leaving the battery fully discharged for months at a time can damage the battery.
Of course, as we all know, the battery has a limited number of charging "cycles". One charge cycle is a cumulation of usage, e.g. if you use 50% of the charge one day, then charge it, then use 20%, and charge, and then use 30% and charge, that totals 100% which equals 1 charge cycle (not 3 charge cycles). Obviously the less you use the battery, the less charge cycles, the longer it will last.
The one point that's a bit difficult to get definitive answer on is "full discharge." From everything I've been able to read up on Lithium-Ion batteries from reliable sources, it ranges from not mattering at all to avoid frequent full discharges. The common point though is that you're not going to damage your battery with full discharges on occasion, and it's even recommended on occasion. You just don't want to leave it fully discharged for a long period of time. Further, the lithium-ion batteries have circuitry that regulates the discharge, preventing full discharges from in actuality reaching absolute "100%" (i.e. 0% charge) - they keep a small amount of power in reserve and will shut the device down prior to 100% discharge to prevent damage.
I know a lot of the following has already been stated here, but one more time... check out Apple's support site on battery usage for yourself. Those are the guidelines that Apple recommends. And no, they don't have any hidden agenda to sell more batteries that way.
The battery is designed to be charged and discharged on a regular basis. It's okay to leave it plugged in most of the time, but it should be charged and discharged at least once per month to keep the electrons flowing. Same with "shallow charges" - perfectly fine, but should be discharged more fully on occasion.
If you're going to store it for a long period of time, you should discharge to about 50% before powering it off. Leaving the battery fully charged for months at a time can damage the battery. Leaving the battery fully discharged for months at a time can damage the battery.
Of course, as we all know, the battery has a limited number of charging "cycles". One charge cycle is a cumulation of usage, e.g. if you use 50% of the charge one day, then charge it, then use 20%, and charge, and then use 30% and charge, that totals 100% which equals 1 charge cycle (not 3 charge cycles). Obviously the less you use the battery, the less charge cycles, the longer it will last.
The one point that's a bit difficult to get definitive answer on is "full discharge." From everything I've been able to read up on Lithium-Ion batteries from reliable sources, it ranges from not mattering at all to avoid frequent full discharges. The common point though is that you're not going to damage your battery with full discharges on occasion, and it's even recommended on occasion. You just don't want to leave it fully discharged for a long period of time. Further, the lithium-ion batteries have circuitry that regulates the discharge, preventing full discharges from in actuality reaching absolute "100%" (i.e. 0% charge) - they keep a small amount of power in reserve and will shut the device down prior to 100% discharge to prevent damage.
The confusion is based in what people mean when they talk about "fully discharged".
The battery indicator on your Mac does not indicate the actual battery charge level, just the useful level to run the system. When people are talking about a fully discharged battery having a shorter life span or being useless or unchargeable they mean from an electro-chemical standpoint where the electrolytes have gone past functional limits at either extreme.
On Apple's battery indicators 0% charge remaining means the battery still has about 5%-10% charge chemically; similarly when Apple's indicator shows 100% the battery may only be 90% chemically charged, this gives them at least part of the headroom to claim 1,000 charge cycles at 80% capacity. Apple uses these limits to make reasonably certain the battery will never reach either extreme of charge.
It's not worth arguing with him at this point. Use=Damage in his view, and there's no changing it.
If he wants to live in fear of using his laptop's battery so be it.
I haven't bothered to read the whole thread, but I've read enough to recommend that you educate yourself about Apple notebook batteries so you don't spread misinformation like this. It does not damage a battery to use it. That's what they're designed for. Never discharging a battery will kill it quicker than using it regularly. You really should read the Apple Notebook Battery FAQ that simsaladimbamba posted, so you can replace your baseless theories with facts.
The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries in older Apple notebooks.
They don't mean draining it to zero, but rather using a charge cycle, which means you could drain to 50% and recharge twice, or drain to 25% and recharge 4 times, etc., and they recommend that for batteries that aren't used regularly.
Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.
The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it. 
Just so that people don't get the wrong impression: It "damages" the battery in the same way as driving your car "damages" the tyres. Discharging to 40% instead of 80% is three times more damage, just like driving 30 miles cause three times more damage to the tyres than driving 10 miles.
A new MacBook battery lasts about 1,000 charges. For many people that's the same or longer than the MacBook lasts. For a few who use their MacBook on the road all day, it's easily replaced (but if it's four years old, you might consider buying a new MacBook and handing the old one over to someone using it as a desktop computer instead of paying out).
I suspect they do this because some people are funny and won't leave the home with their MacBook until it is 100% charged. And the last few percent of charge (the ones after the display already shows 100%) take a very long time.
The the more detailed explanation of what is happening is of course appreciated, but ironically, your post still doesn't address the question, nor GGJ's excellent FAQ post...
Assuming the battery is designed to not allow a "full discharge" in actuality (i.e. to the point where the battery is chemically damaged), from a user's standpoint, does draining the battery down to 0% any more harmful to the battery than draining it 20% or 50%? (and I mean on a chemistry level that would affect the long-term health of the battery)?
I don't want the question to devolve into a matter of semantics, so I'll pose the question another way: If a user drains the battery to 0% (as indicated on the battery level indicator on the screen) every day, is that any more harmful to the battery (i.e. the battery's ability to keep a charge, etc.) than draining it to 50% every day (aside from using up the charge cycles faster of course)?
(p.s. - hey guys - my advice is to stop feeding the troll.
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I would not recommend discharging your battery down to 0%. I usually plug in when it gets no lower than about 5%, and only do that when AC isn't available. As for damage, no, it won't damage your battery, but fully draining it can shorten its useful life.
Yes, I mentioned this in a later post with Wolfpup, thanks.
"I don't think they recommend discharging the battery all the way down, they just say it needs to be used about once a month. They do however state that the laptop should not stay plugged in all the time. This is directly from their lithium battery support document:
Apple does not recommend leaving your portable plugged in all the time."
It does not matter. If you were to take two identical systems in a controlled environment and consistently run one battery down to 50% then charge to 100%, run down to 50%, etc until the battery was "dead" and do the same with the other unit except discharge to 1% you would find that both batteries had the same number of charge cycles of life (within statistical and manufacturing errors).
The MUCH larger factors that wold affect # cycles of life are:
-leaving the battery charged all the time. Just 3 months of 100% charge will noticeably shorten the battery cycle life.
-keeping the battery outside Apple's suggested temperature range
-leaving the battery discharged (run to 0% then don't charge it for a month)
So, just to clarify further, you're saying that something happens to the battery on a battery chemistry level that is different between draining the battery to 0-5% and draining it to 20%?
And if you're not actually sure, that's fine to say so, but again, I think it's confusing to basically say it's "not recommended, but it's not damaging the battery, but it is shortening its life"... that seems contradictory - if it's prematurely shortening its life by using it that way, it must be being "damaged" on a battery chemistry way that's different from shallower discharging?
Again, I really appreciate this discussion!
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Thanks, but some of these "answers" are just rephrasing what I've already stated myself. I specifically indicated in my question that I wasn't referring to charge cycles, which I myself explained how they work in my previous post to that one.
Lithium-ion or lithium-polymer batteries don't respond well to being fully drained. The word "damage" is not appropriate to this discussion. Batteries are consumable items and will die over time, whether they are used much or little, plugged in or not. Fully draining the battery doesn't damage it, per se, but it does shorten the useful life faster than if you don't fully drain it. There is no difference in draining to 80%, 20% or 2%, as long as you don't fully drain it. Apple's recommendation that you not run on AC power all the time isn't a matter of avoiding damage, but a matter of prolonging the useful life.
So you're saying no difference in draining to 80%, 20% or 2%, but it will prematurely shorten the life of the battery if you let it drain to 0%?
Okay, good to know!
I think that depends on how you define "all the time"? If you literally leave it plugged in 24/7/365, it may eventually swell the battery which pretty much sounds like "damage" to me.
Again, part of the confusion on this subject is the constant use of nonspecific terms to describe a subject that seems like it should have very specific answers. It's chemistry and electronics and generally there is right and wrong and exact numbers and everything is measurable... yet Apple's support site on the topic has this to offer: If you unplug your laptop infrequently, discharge it once a month. The "once a month" part is specific. The "infrequently" - no idea what that means - once a day or week, for five minutes or five hours? "Discharge it" - no idea what that means - 20%, 80%, 100%?
My guess to the reason for this (aside from writers not having any better info than we do), is that it's not terribly important one way or the other... as long as you stick to some basic guidelines, and avoid "misusing" the battery (e.g. what the OP was doing), it doesn't really matter if "infrequently" means once a day or once a week. Just use your laptop as you see fit and don't worry about it.
Many batteries swell near the end of their life, regardless of how they've been used. It's not related to leaving it plugged in.
Actually, that's not the case. Battery technology isn't exact, no matter who the manufacturer is. Battery lifespan is affected by a great number of factors and isn't accurately predictable from one user or device to another.
The "once a month" refers to putting at least one cycle a month on a battery that isn't used regularly. It does not apply to batteries in regular use. Too many people take that out of context and fail to read the entire quote from Apple. That's exactly why there is so much misinformation floating around the web.
That is true to a certain extent. There are some guidelines that generally promote longer battery life, and some practices that generally shorten it. Rather than try to nail down specifics that aren't available, it's better to follow the "best practices" that Apple recommends and not worry about the rest. That's why I keep repeating the same statement on battery use:
I'm going to bow out of this discussion after this post; I don't want this to seem contentious or argumentative, because I really appreciate the discussion and what I've learned here, but a couple things I feel the need to respond to...
(* your usage of "one cycle a month" is a good example of being specific and more informative than Apple's usage of "discharge once a month" where "discharge" is left undefined)
That was my initial reaction - correlation without causation. But then there's Apple Store employees saying differently (and yes, I'm well aware they often don't know anymore than anyone posting on this forum), and many anecdotal reports of this under similar circumstances, and it does make intuitive sense that if the electrons stop flowing efficiently, that might result in a "build-up" that would cause swelling. Or that could be complete bunk. But I can't find any credible sources that state one way or the other (and that's no slight to you, but without sources it's just another person on the internet...).
You missed my overall point by a gazillion miles, and I need to refute any implication that my statement leads to misinformation. I know the context, but the context is superfluous - knowing that it refers to "one cycle a month on a battery that isn't used regularly" does not clear up the understanding of nonspecific words like "regularly"...* which was my point. If you want to say that it's impossible to define or give a range to what "regularly" means, that might be the case. However, the unfortunate reality is that kind nonspecific language is what leads to misinformation - it's an internet forum's nature to try and fill in the blanks.
(* your usage of "one cycle a month" is a good example of being specific and more informative than Apple's usage of "discharge once a month" where "discharge" is left undefined)
There have been many reports of batteries swelling, both by users who left their Macs plugged in most of the time, and those who ran on battery quite often. The swelling can appear in both cases, so it's not related to how the battery was used. Occasionally, batteries can swell because they're defective, but they can also do so near the end of their life without manufacturing defects. And you're right, many Apple Store employees frequently know less than many of this forum's members.
I wasn't saying that any particular thing you said was misinformation. My point was that failure to read information in its proper context leads to misinformation, and that there is a lot of misinformation floating around regarding Apple notebook batteries.
The context of the quote gives the specifics you seek:
So the ideal use indicates a daily use on battery power when AC isn't available (such as during a commute on a train in the example), combined with running plugged in (such as at the office). If, on the other hand, your primary computer is a desktop computer, and you only use your notebook for infrequent travel (less frequently than once per month), then you should use your Mac notebook on battery power at least for one cycle's worth every month, rather than letting it sit unused for 2 or more months at a time.
There is no specific measurement required, such as "use your Mac notebook on battery power for 3.2 hours every 4.5 days". Common sense applies that if you're using your notebook on a regular basis, such as daily or a few times a week, make sure some of that time (again, no specific is needed) you're running on battery power, enough that you accumulate at least a cycle or more per month, with more cycles being better.
the battery in my 2010 MBP began to swell after 3 years of being mostly connected in clamshell mode to my 27" ACD. I hardly ever used the battery. It had only 30 cycles on it after 3 years. I had it replaced and gave the MBP to my daughter.
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