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Bubble99

macrumors 65816
Original poster
Mar 15, 2015
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I just read that allowing the battery to drop below 20% before putting it on the charger is really bad for battery health. And allowing it to drop to 1% or even 0% will really destroy the battery health.

Not sure why that the case like does the chemical reaction is very different at that those levels?

But why is there no feature in iOS or iPadOS of an alarm that goes off if the battery is at 20% so it does not go lower.
 

BotchQue

macrumors 6502
Dec 22, 2019
454
617
I'd bet there's a way to write a Shortcut that could do that: have it Wake to check the battery level every 30 minutes or so and if "x < 20%" Then "Play Dying Wookie sound" or something like that (I haven't written a Shortcut myself yet, so forgive my syntax/logic errors!)
 

BotchQue

macrumors 6502
Dec 22, 2019
454
617
Oh, and Apple: a similar alarm at 10% battery life for my Apple TV remote would be equally helpful; my remote battery always seems to die when the obnoxious "Jardiance" commercial comes on and I can't mute it fast enough! 😡
 
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NoBoMac

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Jul 1, 2014
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I'd bet there's a way to write a Shortcut that could do that: have it Wake to check the battery level every 30 minutes or so and if "x < 20%"

Built right into Automations. Have it send a Notification or Alert. No need to put it on a schedule.

battery.png

Back to OP, of course, can turn on percentage value for Battery in settings and see before it gets to 20%. And that it goes red when at 20% is another "alert". And you have battery widget that can have a really big percentage and color on the screen.

So a bunch of options to choose from.
 
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twintin

macrumors 6502a
Aug 10, 2012
767
303
Sweden
What may damage the battery (as far as I know) is if you frequently drain your battery until your phone dies (occational drain has probably little or no effect).

But you already get a ”hint” at 20% (I think) with a popup tellung you your battery level is getting low and asking if you want to enter low power mode.
 

MacCheetah3

macrumors 68020
Nov 14, 2003
2,160
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Central MN
But why is there no feature in iOS or iPadOS of an alarm that goes off if the battery is at 20% so it does not go lower.
As already mentioned, there is:
But you already get a ”hint” at 20% (I think) with a popup tellung you your battery level is getting low and asking if you want to enter low power mode.
You’ll see this message:



It will also occur at lower levels, such as 10-percent. I can’t recall offhand, but the iPad may only show warnings at 10 and 5 percent battery charge (i.e., skips 20).

I just read that allowing the battery to drop below 20% before putting it on the charger is really bad for battery health. And allowing it to drop to 1% or even 0% will really destroy the battery health.

Not sure why that the case like does the chemical reaction is very different at that those levels?
What may damage the battery (as far as I know) is if you frequently drain your battery until your phone dies (occational drain has probably little or no effect).
This is (mostly) untrue, which should be happy news.

Long durations (e.g., weeks or months) at the ‘extremes’ (i.e., less than 10% and greater than 90%) can be permanently damaging to a battery. However, charging to 100% on occasion or frequently but unplugging the device within several hours after it reaches full charge has no/negligeble effect on a battery’s degradation. Similarly, using a device until it automatically powers off due to low battery charge and connecting it to a charger within hours later is also unlikely to harm the battery in any permanent way. Additionally, battery stress is — and has been for a long time — been fairly compensated:

Apple said:

It charges fast for convenience and slow for longevity.​

Your Apple lithium-ion battery uses fast charging to quickly reach 80% of its capacity, then switches to slower trickle charging. The amount of time it takes to reach that first 80% will vary depending on your settings and which device you’re charging. Software may limit charging above 80% when the recommended battery temperatures are exceeded. This combined process not only lets you get out and about sooner, it also extends the lifespan of your battery.

On the other end of the spectrum, iDevices are designed capable of reviving a deep discharged battery.
Apple said:

Store it half-charged when you store it long term.​

If you want to store your device long term, two key factors will affect the overall health of your battery: the environmental temperature and the percentage of charge on the battery when it’s powered down for storage. Therefore, we recommend the following:
  • Do not fully charge or fully discharge your device’s battery — charge it to around 50%. If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life.
  • Power down the device to avoid additional battery use.
  • Place your device in a cool, moisture-free environment that’s less than 90° F (32° C).
  • If you plan to store your device for longer than six months, charge it to 50% every six months.
Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it.

I like this article's description(s):

So where has this nonsense come from? Like all good urban myths: it is based loosely on a couple of pieces of information that have been taken out of context

The article also talks about the trickle charging aspect, although, from a different point of reasoning.
The other reason for only charging to 80% is when you’re at a DC fast-charger. The physics of battery charging is that the time for an EV battery to charge from 0% to 80% is very roughly the same as it takes to go from 80% to 100%.
The situation is similar for Apple’s mobile devices, that is, even if you have them connected to a high-watt capable charger, watch how much slower the battery level increases when going from 90 to 100%.


With that said, hot environments are something you should avoid exposing your battery-equipped devices:
Apple said:

Avoid extreme ambient temperatures.​

Your device is designed to perform well in a wide range of ambient temperatures, with 62° to 72° F (16° to 22° C) as the ideal comfort zone. It’s especially important to avoid exposing your device to ambient temperatures higher than 95° F (35° C), which can permanently damage battery capacity. That is, your battery won’t power your device as long on a given charge. Charging the device in high ambient temperatures can damage it further. Software may limit charging above 80% when the recommended battery temperatures are exceeded. Even storing a battery in a hot environment can damage it irreversibly. When using your device in a very cold environment, you may notice a decrease in battery life, but this condition is temporary. Once the battery’s temperature returns to its normal operating range, its performance will return to normal as well.
again, from:

A couple more for good measure:

Summer heat is tougher on car batteries than winter’s chill. It may seem counterintuitive, but higher temperatures have a greater impact on the power-generating chemistry inside.

While the average car battery lasts 3-5 years across the US, Arizona’s intense heat cuts that time almost in half. You can expect only 2-3 years on average from a regular car battery here before needing a replacement.

Speaking of automobiles… Of course, leaving your iPhone, etc inside a vehicle is very bad:

After just 20 minutes on an 80-degree day, the CDC says the inside of a car can hit 109 degrees Fahrenheit. After 40 minutes, it hits 118 degrees, and after an hour, it can hit 123 degrees. That means that on days when cities are experiencing triple digits temperatures —like Phoenix has been for weeks on end— those temperatures become even hotter in a short amount of time.
 

NoBoMac

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Staff member
Jul 1, 2014
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The situation is similar for Apple’s mobile devices, that is, even if you have them connected to a high-watt capable charger, watch how much slower the battery level increases when going from 90 to 100%.

^This. Start to notice at 80% as well.

Been ages since I've looked at fast chargers as I don't use it often, but back when Apple first introduced it, "speed" was capped at 18W. Any charger that delivered more would negotiate an 18W charge. Here and other sites at the time came to the conclusion that 10-12W chargers were the sweet spot: wallet friendly price point and gives you almost 18W "speed".

(I usually charge at 5W and only occasionally will use the 2x12W charger bedside; never use wireless charging)

 
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FeliApple

macrumors 68040
Apr 8, 2015
3,674
2,076
Because “letting it drop to 1% will destroy battery health” is patently false.

Want to preserve battery life?

-Never update iOS
-Charge slowly (5w) if possible
-Avoid heat

Everything else is, in my opinion, pointless.
 

Helmsley

macrumors 6502a
Sep 4, 2017
722
350
Yorkshire, United Kingdom
Because “letting it drop to 1% will destroy battery health” is patently false.

Want to preserve battery life?

-Never update iOS
-Charge slowly (5w) if possible
-Avoid heat

Everything else is, in my opinion, pointless.

How does not updating iOS preserve battery life? I'm genuinely interested.

Low Power Mode always on is good for battery health, too.
 

FeliApple

macrumors 68040
Apr 8, 2015
3,674
2,076
How does not updating iOS preserve battery life? I'm genuinely interested.

Low Power Mode always on is good for battery health, too.
Note that I said battery life, not health. Newer iOS versions introduce features which always eventually increase power consumption for the same processor, so newer versions always eventually have worse battery life.

This is always evident, but it is massively obvious when you start reaching the end of a device’s support life and compare it to original iOS versions. Grab an iPhone 6s on iOS 15 and battery life will be infinitely worse than what it was on iOS 9; grab a 9.7-inch iPad Pro on iPadOS 16 and compare it to iOS 9; grab an iPhone Xʀ on iOS 17 and compare it to iOS 12, etc. This is regardless of battery health: not even with a new battery do severely updated iOS devices match original version devices.

If you want the best battery life possible for years, you should never update. The vast majority doesn’t do this, but yeah. I do it and I have devices that are considered old today with all-day battery life and no issues.

Take the iPhone 6s for example. Anyone would tell you “the battery of that iPhone is horrible even for light-to-moderate users”. I would reply “no it isn’t”. Grab one on iOS 9 or 10 and it’s a full-day phone even today (I should know, I have one). It’s just that current users forget exactly how good the device was 7 or 8 years ago.

The iPhone Xʀ is excellent in terms of battery life, so much so that Apple released an ad specifically mentioning battery life and how good it was. Current users will complain about it. Not me, because I’m on iOS 12 and I get 18 hours of screen-on time with light use and over 12 with moderately heavy cellular use, which is more than enough for practically any user today. It won’t stop those who have updated it and have suffered the consequences from calling it “a phone with poor battery life” though, when that isn’t the case. I mean, if you update it enough then you suffer the consequences, it’s that simple.

Also, if the device isn’t updated, efficiency is ridiculous. So much so, that battery health itself is irrelevant if the device is on its original iOS version. My iPhone 6s on iOS 10? It has 60% health. Still a full-day phone. People don’t believe this. They don’t believe it because everyone updates. The day somebody stays on an original version for six years like me they will understand.
 

BotchQue

macrumors 6502
Dec 22, 2019
454
617
Some interesting points above.
I've only replaced the battery in one device, my original MacBook Air, before OS "security" updates stopped coming for that device; I tend not to upgrade any hardware until that happens (mebbe I shouldn't have written that out where Apple could see it...). I'm on my original iPhone, the SE v2, and because I'm not a power user on the phone, nor do any banking/purchasing on it, I'll continue to use it, even after the security updates stop coming, until the battery goes completely Tango-Uniform (I'll let you guys know when that happens, its current health is at 81%).
 

I7guy

macrumors Nehalem
Nov 30, 2013
34,361
24,107
Gotta be in it to win it
Because “letting it drop to 1% will destroy battery health” is patently false.

Want to preserve battery life?

-Never update iOS
-Charge slowly (5w) if possible
-Avoid heat

Everything else is, in my opinion, pointless.
That it’s patently false is false. Leaving an li-ion battery sit at an extreme stage of charge (as well as other factors such as extreme heat) will destroy battery health, which is related to battery life.
 

FeliApple

macrumors 68040
Apr 8, 2015
3,674
2,076
That it’s patently false is false. Leaving an li-ion battery sit at an extreme stage of charge (as well as other factors such as extreme heat) will destroy battery health, which is related to battery life.
Did I say to leave it at 1%? (Or 100%)?

Letting it drop to 1% on an original iOS version will not worsen battery life.

Battery health degrading on an original iOS version will not worsen battery life.
 

I7guy

macrumors Nehalem
Nov 30, 2013
34,361
24,107
Gotta be in it to win it
Did I say to leave it at 1%? (Or 100%)?

Letting it drop to 1% on an original iOS version will not worsen battery life.

Battery health degrading on an original iOS version will not worsen battery life.
Degrading battery health leads to worse battery life. To compensate for reduced number of peak hours less of a load is applied to keep the same number of hours.
 

FeliApple

macrumors 68040
Apr 8, 2015
3,674
2,076
Degrading battery health leads to worse battery life. To compensate for reduced number of peak hours less of a load is applied to keep the same number of hours.
If updated enough, yes, absolutely.
 

Bubble99

macrumors 65816
Original poster
Mar 15, 2015
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296
That it’s patently false is false. Leaving an li-ion battery sit at an extreme stage of charge (as well as other factors such as extreme heat) will destroy battery health, which is related to battery life.

Want is the difference if the battery sits at below 20% for two or three days than charging the battery every day where it going from 0% to 100% but not sitting at that charge but being use as to well being apposed to sitting below 20% or above 80%
 

Bubble99

macrumors 65816
Original poster
Mar 15, 2015
1,093
296
^This. Start to notice at 80% as well.

Been ages since I've looked at fast chargers as I don't use it often, but back when Apple first introduced it, "speed" was capped at 18W. Any charger that delivered more would negotiate an 18W charge. Here and other sites at the time came to the conclusion that 10-12W chargers were the sweet spot: wallet friendly price point and gives you almost 18W "speed".

(I usually charge at 5W and only occasionally will use the 2x12W charger bedside; never use wireless charging)


As already mentioned, there is:

You’ll see this message:



It will also occur at lower levels, such as 10-percent. I can’t recall offhand, but the iPad may only show warnings at 10 and 5 percent battery charge (i.e., skips 20).



This is (mostly) untrue, which should be happy news.

Long durations (e.g., weeks or months) at the ‘extremes’ (i.e., less than 10% and greater than 90%) can be permanently damaging to a battery. However, charging to 100% on occasion or frequently but unplugging the device within several hours after it reaches full charge has no/negligeble effect on a battery’s degradation. Similarly, using a device until it automatically powers off due to low battery charge and connecting it to a charger within hours later is also unlikely to harm the battery in any permanent way. Additionally, battery stress is — and has been for a long time — been fairly compensated:



On the other end of the spectrum, iDevices are designed capable of reviving a deep discharged battery.


I like this article's description(s):



The article also talks about the trickle charging aspect, although, from a different point of reasoning.

The situation is similar for Apple’s mobile devices, that is, even if you have them connected to a high-watt capable charger, watch how much slower the battery level increases when going from 90 to 100%.


With that said, hot environments are something you should avoid exposing your battery-equipped devices:

again, from:

A couple more for good measure:





Speaking of automobiles… Of course, leaving your iPhone, etc inside a vehicle is very bad:



Is it some laptops, phones and new EV show 100% when it is 80% and 0% when it is 20% ?
 

MacCheetah3

macrumors 68020
Nov 14, 2003
2,160
1,126
Central MN
Is it some laptops, phones and new EV show 100% when it is 80% and 0% when it is 20% ?
I’m not certain about EVs, however, iPhones, iPads, MacBooks, etc do have unseen margins. For example, when your iPhone automatically shuts down because of low battery, there’s probably 10% or so of actual battery capacity/charge remaining. This helps prevent deep discharge states, allows the device to show the low battery/connect to charger symbols, and even extend Find My services for a little longer.
 

FeliApple

macrumors 68040
Apr 8, 2015
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If the battery is abused enough for sure.
And if it isn’t as well, but unlike original iOS versions, there is a difference between a degraded battery and a new one if it’s updated enough.

This sadly means that for devices pushed to their update limits, a battery has to be replaced every five minutes because it can’t cope with anything. An iPhone 6s on iOS 15 is useless today because battery life is abhorrent with 100% health, let alone 80%. Quick cycle counts because battery life sucks, faster degradation, worse battery life. It makes perfect devices utterly useless.

My 6s on iOS 10 on the other hand... flawless, with enough battery life for a full day as a moderate user even with the original battery.

Which, going to the thread, makes it utterly pointless to keep a device for years and engage in battery conservation while updating it, because you aren’t maintaining battery life regardless of what you do.
 

I7guy

macrumors Nehalem
Nov 30, 2013
34,361
24,107
Gotta be in it to win it
And if it isn’t as well, but unlike original iOS versions, there is a difference between a degraded battery and a new one if it’s updated enough.

This sadly means that for devices pushed to their update limits, a battery has to be replaced every five minutes because it can’t cope with anything. An iPhone 6s on iOS 15 is useless today because battery life is abhorrent with 100% health, let alone 80%. Quick cycle counts because battery life sucks, faster degradation, worse battery life. It makes perfect devices utterly useless.

My 6s on iOS 10 on the other hand... flawless, with enough battery life for a full day as a moderate user even with the original battery.

Which, going to the thread, makes it utterly pointless to keep a device for years and engage in battery conservation while updating it, because you aren’t maintaining battery life regardless of what you do.
a new operating system pushes older hardware to its it’s limit. After the iPhone XS the days of obliteration were over on iPhones.

The iPhone 6s was great back in the day. But an inefficient processor and quickly showed its age compared to newer processors.

While you keep touting a full day on an iPhone 6s on iOS 10, unless the performance is comparable in every aspect to a more modern phone running similar tasks; you’re using a degraded phone and calling it flawless.
 
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FeliApple

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Apr 8, 2015
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a new operating system pushes older hardware to its it’s limit. After the iPhone XS the days of obliteration were over on iPhones.

The iPhone 6s was great back in the day. But an inefficient processor and quickly showed its age compared to newer processors.

While you keep touting a full day on an iPhone 6s on iOS 10, unless the performance is comparable in every aspect to a more modern phone running similar tasks; you’re using a degraded phone and calling it flawless.
You know you’re asking for something impossible, at least now. When iOS 13 was the latest, iOS 10 was probably almost fully functional. Not today, sadly.

But in end it’s the same: a device either works properly throughout its entire lifespan with great battery life regardless of health, and, with a little luck, that lifespan is long, or it degrades quickly into obliteration two or three years after purchase. Nine years later the result is similar, but at least keeping it on iOS 10 you get a pleasant experience with no need for battery preservation, like the OP asked.

Today? A fully updated 6s is so unpleasant that support is pointless regardless. At least for me, if people tolerate obliteration then more power to them...
 
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Bubble99

macrumors 65816
Original poster
Mar 15, 2015
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You know you’re asking for something impossible, at least now. When iOS 13 was the latest, iOS 10 was probably almost fully functional. Not today, sadly.

But in end it’s the same: a device either works properly throughout its entire lifespan with great battery life regardless of health, and, with a little luck, that lifespan is long, or it degrades quickly into obliteration two or three years after purchase. Nine years later the result is similar, but at least keeping it on iOS 10 you get a pleasant experience with no need for battery preservation, like the OP asked.

Today? A fully updated 6s is so unpleasant that support is pointless regardless. At least for me, if people tolerate obliteration then more power to them...

You not saying how long these battery are to last are we talking 3 years or like 6 years?
 
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