what are consequences of short battery cycles

MichelPM wrote:

Once a month, you need to let the device drain ALL THE WAY DOWN TO 0% then charge all the way back up to 100%.

Absolutely not necessary at all with any Apple lithium battery powered device. Doing so serves no purpose at all.

In fact with any modern lithium polymer cell, deep discharges do nothing more than somewhat accelerate the rate of loss in capacity with age. They don't aid in maintaining the battery or prolonging capacity and useable lifespan.

See http://www.apple.com/batteries/why-lithium-ion/

The only reason for doing full discharge/charge cycles with older devices was to calibrate the battery meter indicator anyway - other than that very limited reason, full cycle discharges served no purpose even back in the day when they were recommended.

Is 2014 out of date? Perhaps it is but this is what Apple Support

call service was giving as advice 3 years ago?! I found this link:

See http://www.apple.com/batteries/why-lithium-ion/

given by you in this discussion useful. It seemed to me

that it is suggesting no need to go to zero, but to go to less than

20% once a month, isn't it?

In the link offered:

http://www.apple.com/batteries/why-lithium-ion/

it says: "...With lithium-ion batteries, the capacity diminishes slightly with each complete charge cycle...."

What is your understanding of what is being said here?

Is this saying that it is in fact better to charge, 'as needed', and not let the

battery run down to low, even once a month, even on a device like the

Mac Book Air (mid 2013; 2015) 10.10.5 -which I am using?

I hope that you can clarify and that your answer might be labelled 'Apple Recommended" to put this issue to rest : for brand new devices and older

ones, each to their own needs.

Thank you for you time and consideration.

You can charge up an iDevice anywhere from betwen 10%-90% back to 100%.

Once a month, you need to let the device drain ALL THE WAY DOWN TO 0% then charge all the way back up to 100%.

iDevices can be drained all the way down to 0% with no adverse effects or shortening battery life once every month, or so.

Don't let the battery linger drained all the down to 0%. Once your iDevices battery drains to 0 and your iDevice shuts down, put it on the charging/transformer block and let it charge up to 100%.

It is good to let lithium ion batteries undergo a full charge cycle every 4-6 weeks or so to exercise the battery's full charging range.

Good Luck!

I find that that is a bit confusing information, as Apple Support specifically suggested letting go below 20% -- to 5-10% before retiring, saying the battery charges more reliably to what the % reads that way. Units that recharge reuseable batteries in my experience indicate that in fact rechargeable batteries do like to get emptied out to charge up most optimally.

Is there an Apple document that speaks directly to this?

You can let the battery go under 5% once to calibrate the battery (which is useless as Apple ship calibrated batteries but well), the issue would be to do this often and deliberately.

Unfortunately Apple don't tell a lot about batteries and how to use them the best but you can go to conferences (which I do) or find research papers on the web.

allan299 wrote:

also, I have read in reliable sources that an at least once a month, letting the battery

empty to 5-10% before charging, fully, is a good practice.

Again, very out of date information in whatever you are reading. Not relevant to current generations of industry standard SMART lithium polymer cells.

allan299 wrote:

Does what I am saying applying to the computers that I am using:

Mac Book Air (mid 2013) and 2015 [10.10.5]?

It applies to lithium batteries, both of those machines use a lithium battery. And it also says:

It makes charging easier.

Charge your Apple lithium-ion battery whenever you want. There’s no need to let it discharge 100% before recharging

? Nowhere in that link is there any suggestion of any minimal discharge state to target. You can basically charge at any time, at any level, and to any extent, entirely as is most convenient to do so.

It is suggested by numerous technical documents to in general try to avoid deep cycle discharges with any lithium battery as much as possible, as they do hasten the degradation in capacity. Other than that, just charge as often and for as long as is convenient to do so. And as long as it is convenient to do so, you'll do well to charge before the battery hits a very low discharge state.

That advice applies to any Apple or other lithium battery device. The deep discharge cycles of older devices served the sole purpose of keeping the battery indicator calibrated with the battery as it degraded with age and use. They did nothing good for the battery at all. Modern lithium cells are self-calibrating in the data they report to the battery level display.

Charging overnight has the advantage of also allowing for a nightly iCloud backup when the device is plugged in, powered on but in sleep mode and connected to wifi.

Reread the article, and you are correct when you say: "? Nowhere in that link is there any suggestion of any minimal discharge state to target."

You say: "And as long as it is convenient to do so, you'll do well to charge before the battery hits a very low discharge state."--

But, is this true only for the latest devices and iOS systems, or also for Mac Book Air (mid 2013; 2015) 10.10.5 devices as well?

You say: "The deep discharge cycles of older devices served the sole purpose of keeping the battery indicator calibrated with the battery as it degraded with age and use." But this is a useful purpose, "keeping the battery indicator calibrated", when you need to know that it is reliable in it's indications, isn't it. If the Macs I mentioned that I am using are not in need of monthly

deep discharges to remain calibrated, I'd be thrilled. I hope

you'll inform participants owning older devices, in my case 2013 and 2015, about this piece of the puzzle.

Well I thought that it was saying, 'with each complete cycle' to refer to the thread of the discussion here, and to mean that that capacity diminished

more quickly when a complete cycle (0-100% charge) was accomplished, all at once. Might that also be it's meaning?

I must be overthinking this.😊

Thank you for your patience and precise answers.

It was a helpful and useful discussion for me.

I was stuck mainly because the advice that I shared

was given to me by the Apple Support line, and I

believed they knew what they were talking about

but from reading Level 9 posts in different discussions

on this forum, perhaps they don't, always.

Lithium batteries decay from the very moment they are assembled. A lithium cell loses capacity just sitting on a shelf, from internal oxidation and decay. And every use also degrades capacity. Lifespan is measured, for practical purposes, by full discharge/charge cycles or their equivalent accumulated over multiple partial cycles. Full cycle equivalents is a more meaningful measure of lifespan than simple time.

The simple plain fact is every lithium cell has a finite life span. Used or unused and regardless of storage conditions If left unused. Cycles are simple used as a convenient measure of use. But every time current passes into or from the battery, it is degrading. Sitting idle it is degrading. Capacity continually diminishes, no matter what.

So trying to micromanage charge state for enhanced life span is an exercise in pointless frustration. You may, at the very best, gain a minutely fractional longer useful lifespan of the battery, but odds are you won't affect how long it practically lasts you one bit. And by following antiquated and out of date advice like frequently forcing deep discharge cycles will simply lead to even more rapid decay that otherwise.

BTW, none of this is new for SMART industry standard lithium batteries (be they in your iPad or your electric toothbrush or anything else). For a technology that has been in wide spread use for decades now, the amount of misinformation, urban myth (driven by carry over from older technologies like NiMH) and outright FUD is astounding.

I am so tired of hearing from the peanut gallery on this.

I have been charging ALL of my iDevices like this for years!

My 2nd gen iPod Touch is 8 years old! My original iPad 1 is six years old!

I have been charging these devices this way for ALL of these years, folks!

Has not affected battery performance or shortened the battery life of any of my iDevices far as I can tell, to date!

Even Apple recommends this method in THEIR support articles!!!!

Look it up!!!

I found Apple's info earlier, but I am NOT searching for it for any of you, again!

You people are soooo tiresome and like a dog with bone on this topic!!

I worked in this field for many, MANY years before switching careers and I keep up on battery technologies, even now!

I am not getting into another circular argument with all of you "so called experts" on this topic when this method is even recommended by Apple!

MichelPM wrote:

Even Apple recommends this method in THEIR support articles!!!!

No they do not. They did, but they have no longer done so for several years. Battery technology is not static, and Apple's recommendations have changed as they have worked with their suppliers and improved the technology used in their devices.

Rant all you want, but your information was inaccurate and out of date. Apple has not recommended any form of regular or repeated full cycle discharge/charge cycle in over 2-3 years now.

If we're the peanut gallery, then your post makes you sound like some petulant child who'se had their feelings hurt.

(everyone I know here, myself included, has been wrong at one time or another, about one thing or another. It's hardly a reason to get upset over a post or thread).