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The battery health for my Macbook Air is at 78 percent health after only 282 cycles. Isnt it supposed to remain above 80 percent if under 1000 cycles? I have noticed a drop in the time that it holds charge and my Macbook Air is warning me that I need to service my battery, this isnt normal is it?
MacBook Air, OS X Mountain Lion (10.8.3)
if you have had if you 1 year or less, or have applecare the battery is covered under the warranty.
Thanks for the reply. No I have had it for about 15 months now I think. If the battery hasnt lasted as long as it should have shouldnt Apple have to replace it though?
not after the warranty expires.
1. did you often drain the battery very low?
2. did you often /always have your macbook on charge,......or did you often / always BOTH have your macbook on charge AND in sleep mode?
1 or 2 are harsh on the battery chemistry and therefore its longevity
I have been travelling for the past 9 months and using it daily, tis means I use it in all kinds of scenarios.
Sometimes I use it on a bus/train and almost fully discharge it then recharge once I reach my hostel.
Sometimes I use it while plugged into the wall, but not always.
When I recharge it it is always in slep mode. I was under the impression that the macbook air was designed to be left in Sleep mode as the longevity of its sleep mode is one of its selling points...
... The scenarios you are describing above are really the only way one would expect to use a laptop arent they?
SkareMedia wrote:
When I recharge it it is always in slep mode.
Ah, I see
I was under the impression that the macbook air was designed to be left in Sleep mode
Sleep mode yes, always in sleep AND on power, no
Recharging it in sleep mode is fine, some people however use their notebooks like desktops and BOTH always have it on power and in sleep mode.
to wit:
"Apple does not recommend leaving your portable plugged in all the time."
However it doesnt sound as if you have yours plugged in 'all the time' (or is that not the case?)
If the massive amount of data that exists on lithium batteries were to be condensed into a simplex, helpful, and memorable bit of information it would be:
1. While realistically a bit impractical during normal everyday use, a lithium battery's longevity and its chemistry's health is most happy swinging back and forth between 20% and 85% charge roughly.
2. Do not purposefully drain your battery very low (10% and less), and do not keep them charged often or always high (100%).
3. Lithium batteries do not like the following:
A: Deep discharges, as meaning roughly 10% or less on a frequent basis.
B: Rapid discharges as referring to energy intensive gaming on battery on a frequent basis (in which case while gaming, if possible, do same on power rather than battery). This is a minor consideration.
C: Constant inflation, as meaning always or most often on charge, and certainly not both in sleep mode and on charge always or often.
From Apple on batteries:
Ah thanks for the info. Yeah I do not think I would qualify as abusing my battery in any of the ways you have listed.
As I am traveling the only time I leave my laptop on charge and in sleep mode is when I reharge it overnight. In the morning it will usually be packed in my bag or locker for the day. I might use it that evening to do photo editing, sometimes on charge but usually not.
A. I would say I only discharge my battery to 10 percent or less maybe once every 2 weeks, which shouldnt be considered frequent I imagine.
B. I do not do any gaming, mostly research, browsing, typing and photo editing. Very rarely these days I do 3D animation and video Editing but that may only be once a month or so.
C. As I am traveling the only time I leave it on charge for long periods while in sleep mode would be overnight and then disconnect the charger in the morning. Again this would be normal laptop activity.
All that being said would you consider a battery health of 78 percent at this point abnormal?
Thanks, Chris.
SkareMedia wrote:
All that being said would you consider a battery health of 78 percent at this point abnormal?
Thanks, Chris.
that 78% is just a rough calculation, and except for long term, cycle counts contrary to much panic from others about same doesnt really amount to anything.
Any battery will have to be replaced even if its perfect and treated perfectly, and is a consumable.
you said: "As I am traveling the only time I leave it on charge for long periods while in sleep mode would be overnight and then disconnect the charger in the morning"
sounds like you do that a "lot". Not the case? If so that would account for something in battery chemistry.
While cycle count is commonly seen to be the “miles” on your Lithium Ion pack cell in your Macbook, which they are, this distinction is not a fine line at all, and it is a big misconception to “count charge cycles”
*A person who has, for example, 300 charge cycles on their battery and is recharging at say 50-60% remaining of a 100% charge has better battery usage and care than another person who has 300 charge cycles at say 15% remaining on a 100% charge.
DoD (depth of discharge) is far more important on the wear and tear on your Macbook battery than any mere charge cycle count. *There is no set “mile” or wear from a charge cycle in general OR in specific. As such, contrary to popular conception, counting cycles is not conclusive whatsoever, rather the amount of deep DoD on an averaged scale of its use and charging conditions.
(as a very rough analogy would be 20,000 hard miles put on a car vs. 80,000 good miles being something similar)
In a lithium battery, deep discharges alter the chemistry of the anode ➕ to take up lithium ions and slowly damages the batteries capacity for the cathode ➖ to transport lithium ions to the anode when charging, thereby reducing max charge levels in mAh. In short, radical swings of power to lithium cells disrupts the chemical ecosystem of the battery to hold charges correctly which likewise impedes the perfect transfer of lithium ions both in charging and discharging. In charging your lithium battery, lithium ions are “pushed uphill” (hard) to the anode, and discharged “downhill” (easy) to the cathode when on battery power. Deep discharges, damages this “upward” electrolyte chemistry for the battery to maintain a healthy charge and discharge balance relative to its age and cycles.
From BASF: How Lithium Batteries work
https://www.youtube.com/watch?v=2PjyJhe7Q1g
A really EASY way to understand a lithium battery is like a bottle full of water and a handful of sand inside with a mesh in the middle of the bottle for the sand to pass thru, ...
as you tip the 'bottle' (battery) from the bottom cathode ➖ to the top anode ➕ , and the sand (lithium ions) passes thru the mesh, all is fine, however if you leave it bottom down too often or too long (low charge), the sand will stick and form crusty clumps and then not move to the other side (to a charged state). Lithiums hate to be settled bottom down, rather laying horizontal as an analogy, half and half, swinging back and forth to keep the sand moving.
A lesser situation against the battery is where a battery is always / near 100%, and on charge AND sleep mode ...its top (anode) down and get tipped a bit, off and on, on and off, that forms barrier at the top which also affects lithium ion movement (in this analogy sand).
In this analogy, all the sand bottom down is very harsh on Lithium battery chemistry, and always at the top, not ideal, and not recommended "always / often".
Ideally, as stated, a Lithium battery is best used like tabletop wave machine, sloshing lithium ions back and forth, where theres always about 20% or so minimum between top and bottom at all times.
This is, obviously, not realistic in real world use, but knowing a perfect ideal, paints a better parameter for use.
Thanks for the info. I guess I will just have to take it to an apple store when I get a chance and see what they say. As of today though my battery health has dropped to 74 percent, so it definately seems like something is amiss to me, but I will wait and see what the geniuses say.
what OS are you running...?, there are in some instances with 10.9 and 10.9.1 occurances where the SMC is reporting wrong 'time remaining' and batt. health.
The real test, forget about 'health' which is just algorithms , is charge to 100% and run ONLY web (no video) and text, and report back at how long in time it takes to get down to 50%.
😊
I know this was a few months ago, but i finally had a chance to go to a genius bar. They tested the battery and confirmed the health had dropped to 72 percent after just a little more than 300 cycles and confirmed that it isnt normal. They couldnt say what might have caused it to happed so quickly and could only say it must have been a faulty battery... After they said that I almost expected them to replace it free of charge, however they didnt 😟 I had to fork out almost $200 for a replacement battery.
SkareMedia wrote:
health had dropped to 72 percent after just a little more than 300 cycles and confirmed that it isnt normal.
You dont understand. If so inclined, I can destroy a battery on a mere 150-200+ or so cycles.
what you think battery cycles are, and what they actually are, are 2 different things.
Cycle count is NOT what kills a battery in 1, 2, 3 years of good use, its the wrong abuse of the battery in those 1-3+ years.
Proper understanding of a battery charge cycle
Two examples for clarification:
As a first example, where one fully charged battery is discharged down to 10%, then fully recharged, then using 10% of that full charge, this counts as 1 cycle since the total of both discharges is 100% of a full charge of use.
In the second example, where one fully charged battery is discharged down to 40%, then fully recharged, then using 40% of that full charge, this also counts as 1 cycle since the total of both discharges is 100% of a full charge of use.
While both examples are that of a single charge cycle, the first example is more aggressive against the lithium battery chemistry than is the second example. In short, collective overall gentle shallow or mid-range draining of your lithium battery is a better use condition than is the first example of deep-draining of the battery. While both are quantitatively identical as a single charging cycle, they are wholly different qualitatively on the battery chemistry, which is directly related to its ultimate longevity and health.
In short, it is the near and mid-term life of the battery as relates to its proper care (or lack thereof) that is to be looked after.
Priorities in order of decreasing importance for battery care are:
1. Avoiding deep discharges of the battery.
2. Avoiding having your battery constantly on charge or on charge and in sleep mode.
3. When playing graphics intense games, use your notebook plugged in when possible.
4. Reduction of battery cycles by plugging into power when on the go, or when accessible.
A person who has, for example, 300 charge cycles on their battery and is recharging at say 40% remaining of a 100% charge has a better battery condition state than, say, another person who has 300 charge cycles on their battery and is recharging at say 10-15% remaining on a 100% charge. DoD (depth of discharge) is vitally important on the wear and tear on your Macbook’s battery, much more so than is the counting of charge cycles. There is no set “mile” or wear from a charge cycle in specific. Frequent high depth of discharge rates (draining the battery very low) on a Lithium battery will greatly hasten the lowering of maximum battery capacity.
Understand that a charge cycle is a general parameter of use, but is not directly related to the short-term or mid-term abuse of the battery, which can rapidly hasten a shorter lifespan, regardless of what the actual cycle count on the battery indicates.
Proper considerations for near-term care of the battery is of utmost importance. Abuse of the battery is entirely avoidable, long-term eventual old age deterioration of the battery is entirely unavoidable.
Thanks,
I read through your previous posts about what a cycle count actually means, but it still seems to me that my battery use was pretty normal and it should not have failed this badly, this early.
I dont discharge it often.
It's not constantly on charge.
I dont play games, but sometimes do somewhat intense 3D work, but usually it will be on charge while I do this.
The "genius" took my macbook air and ran some tests on the battery using some method I have never seen which kept failing and confirming that the health of the battery was way below normal. Wehn I explained how I use my laptop he seemed adamant that the battery must have been faulty and it had not been caused by the way I was using it.
I didnt have time to complete the web/text test down to 50 percent, but I would say the battery would have lasted around 2 hours max if I had have done the test.
Thanks, Chris.
SkareMedia wrote:
I dont discharge it often.
It's not constantly on charge.
I dont play games, but sometimes do somewhat intense 3D work, but usually it will be on charge while I do this.
The "genius" took my macbook air and ran some tests on the battery using some method I have never seen which kept failing and confirming that the health of the battery was way below normal.
Define OFTEN from above.
After answering that question,
the only remaining possible is a defective Lithium pack.
Macbook Air (13 inch Mid 2012) Battery health under 80 percent
