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novetan

macrumors 6502
Original poster
Sep 3, 2010
390
10
I just bought a 14 PM but I supposed this topic is also applicable to other phones of recent models. The more I read abt preserving batt life the more confusion tossed up. So I’m coming here to seek clarification which I believed some tech geeks here are knowledegable.

Whats the best way to charge 14 PM to preserve the battery. This is what I gathered fr the general consensus fr google articles (I understand some could be also unrealiable).

1) charge between the range of 20% to 80%. Once its down to 20% can begin charging. Don’t wait till almost zero. And once it reaches 80% stop charging. Don’t full charge to 100%. Can someone explain the logic behind the 20-80%. Is the 20-80 rule accurate?
2) As far as possible always use a slow charger like 5w. Why? It seems fast chargers are all marketing hype, kinda a race whose brand is faster. I recently spoke to an Apple staff and he said the sweet spot is abt a 20w charger. A slower charger will in fact make the battery struggle for juice and will render the battery more harm than good.
3) Don’t charge overnight. But if it’s a slow charger, why not?

Lastly, on a normal day if one is not in a hurry neither do wanting to wait to long, whats the best wattage (or sweet spot) for a charger for 14 PM.

Tks so much
 
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James6s

macrumors 6502a
Sep 22, 2015
699
1,192
Cumbria, UK
I have a 14PM with 100% BH after one year (132 full charge cycles) I used to charge it with an Apple 18w before that went faulty and stopped charging. Now I use an Anker nano 30w.

I charge it once per day in the morning when I wake up. Most mornings the battery is down to around 40% (give or take a few %) after 24hrs, I then let it charge to between 90-95% and occasionally up to 100%.

Very rarely it gets between 10-20%, less than once per month.

Never been charged overnight and on a particularly heavy usage day I’ll give it a quick top up in the evening.

The less full charge cycles used up = slower battery degradation.
 

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Al Rukh

macrumors 65816
Nov 15, 2017
1,143
1,276
It doesn’t make a huge difference. Just use/charge your iPhone as you like. After a year or two if the battery goes down below 90%, get a new battery or a new phone. Don’t stress over something trivial like battery health.
 

novetan

macrumors 6502
Original poster
Sep 3, 2010
390
10
You know is frustrating after almost a full charge and then 3 hrs later while you are out merely using the phone sparingly and the battery suddenly dropped to 10%. All because of no battery charging discipline. Am not the one like to change phone every one or two yrs, neither to spend unneccessary money on battery if it can be preserved. Adopting some charging regime won't stressed me out.
 
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Al Rukh

macrumors 65816
Nov 15, 2017
1,143
1,276
You know is frustrating after almost a full charge and then 3 hrs later while you are out merely using the phone sparingly and the battery suddenly dropped to 10%. All because of no battery charging discipline. Am not the one like to change phone every one or two yrs, neither to spend unneccessary money on battery if it can be preserved. Adopting some charging regime won't stressed me out.

What you have is a battery life issue, not a battery health issue. How you charge your phone does not have an impact how well your phone can hold its charge. Look into other factors like cellular signals, rogue background app activity and so on. Assuming your existing battery health is more than 80%.
 
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ChoiMinji

macrumors 6502
Jul 5, 2021
353
386
As far as possible always use a slow charger like 5w. Why? It seems fast chargers are all marketing hype, kinda a race whose brand is faster.
Agree, low watt chargers are the the way to go. Don’t want the battery to get hot.
I used a magsafe charger on the 12 mini and it killed the battery, was always getting hot, it got hot during the wee hours of the morning while everyone was asleep…weird. After I realized it was doing all the time it was too late.
 

one more

macrumors 601
Aug 6, 2015
4,542
5,712
Earth
After using a 12 mini extensively for almost three years (its current original battery health is at 84%), my advise would be:

1) Avoid overheating your battery, so do not charge it with high W chargers or during power intensive activities, like video calls. For the same reason (overheating), I also try to avoid wireless chargers;

2) I used and still use Apple’s original 5W charger and mostly charged my iPhones overnight. Mini would charge to a 100%, my current 15 is limited to 80%;

3) For occasional rapid topups, I do use Apple’s 20W charger or a USB charger in my car (not quite sure about its output).
 
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JPack

macrumors G5
Mar 27, 2017
12,668
23,570
The 80/20 rule is to avoid extreme states of charge. Research shows extreme states reduce the total available cycles and charge capacity.

No such thing as “struggle for juice” LOL. The idea behind using 5W chargers is to reduce heat generated by the battery. When you charge, chemical reactions are taking place which generate heat. The people selling chargers don’t care about your battery health and they’re concerned about selling you more expensive chargers.

Charging discipline is about maximizing the health of your battery. Some of it is also luck depending on the quality of the battery you get.
 
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P_Watt

macrumors regular
Dec 10, 2018
240
152
1) charge between the range of 20% to 80%. Once its down to 20% can begin charging. Don’t wait till almost zero. And once it reaches 80% stop charging. Don’t full charge to 100%. Can someone explain the logic behind the 20-80%. Is the 20-80 rule accurate?
20/80 is a myth. Discharging to zero is a big no-no however.
There is no point worrying about battery max capacity (incorrectly named Health) dropping by a few percent if you are only ever going to use 60% of it at any time. May as well have 60% health.
I say charge every night all night on slow charge because
1. Optimised charging in most iPhones plus 5watt charger will prevent overheating and
2. Housekeeping events like photos curation need the phone to be locked, on Wi-Fi, and on charge and
3. All the time it is on charge it cannot discharge.
Heat, and usage (discharge), are the main factors affecting ageing.
 

Mr.Fox

macrumors regular
Oct 9, 2020
157
85
I just bought a 14 PM but I supposed this topic is also applicable to other phones of recent models. The more I read abt preserving batt life the more confusion tossed up. So I’m coming here to seek clarification which I believed some tech geeks here are knowledegable.

Whats the best way to charge 14 PM to preserve the battery. This is what I gathered fr the general consensus fr google articles (I understand some could be also unrealiable).

1) charge between the range of 20% to 80%. Once its down to 20% can begin charging. Don’t wait till almost zero. And once it reaches 80% stop charging. Don’t full charge to 100%. Can someone explain the logic behind the 20-80%. Is the 20-80 rule accurate?
You are reading the wrong things and filling your head with unnecessary information. You have a new device. The battery is new. It is necessary to perform the so-called correct commissioning, so that the battery reaches the plateau. And that's about 20-30 charge cycles.
Not all chargers provide a full charge and the battery may not be fully charged when the "ready" signal appears; the 100% charge on the fuel gauge may be false. The battery is best charged at 5-8% residual voltage and up to 100%.
Why charge the battery for 14 hours? Do you have nickel-based batteries (NiCd and NiMH) in your phone? No. These batteries have a memory and are put into operation at a certain temperature and charge from 14-16 hours. You will kill it that way + burn out the power controller.
The 20% to 80% charge range is a mistake that everyone has picked up on and unknowingly copied on everything. These batteries are used in electric cars.
The makers of the Nissan Leaf, BMW and other electric cars use the proven lithium-manganese (LMO) battery, with a mixture of NMC.
The famous Tesla uses NCA (nickel,cobalt,aluminum) and lithium-nickel-manganese-cobalt-oxide elements (old version)
New batteries are charged between 30% -80% . As the battery ages, more of the battery's usable capacity is required, resulting in more load and accelerated aging. Not to be confused with phones, tablets, watches, laptops!!! It is not applicable for charging Li-ion (Li-ion, polymer) based batteries, which are used in phones and other wearable electronics.
Batteries can be discharged to the value "0" and can be charged to 100. and nothing will happen to them. Batteries are afraid of deep discharge. To achieve this, you must keep the battery discharged for several years!
2) As far as possible always use a slow charger like 5w. Why? It seems fast chargers are all marketing hype, kinda a race whose brand is faster. I recently spoke to an Apple staff and he said the sweet spot is abt a 20w charger. A slower charger will in fact make the battery struggle for juice and will render the battery more harm than good.
Tell him he's an idiot.
The maximum charging current that a Li-ion battery can handle is determined by the cell design, not the cathode material as is commonly assumed. Outdated batteries are afraid of fast charging and should be avoided.
As far as possible always use a slow charger like 5w. Why?
The lithium-ion battery operates safely within the specified operating voltage; however, the battery becomes unstable if it is accidentally charged to a voltage higher than specified. Prolonged charging of a lithium-ion battery above 4.30V, rated at 4.20V/cell, will result in the formation of metallic lithium on the anode. So clear without delving into chemistry, physics, and basic battery design engineering? In doing so, I'm discarding the different types of batteries and their construction features and the corridor of safe charging at low and high voltages
3) Don’t charge overnight. But if it’s a slow charger, why not?
The lithium-ion battery cannot absorb overcharging. When fully charged, the charging current must be switched off. Continuous trickle charging can cause metallic lithium to form and jeopardize safety. The battery will enter a stressed state. It may lose its capacity, it may swell, it may be punctured, it may explode.
Critically low voltage cannot fully replenish the cell's charge, which will result in heat generation and the battery will go into parasitic charging


I feel a new wave of indignation will soon rise, why new batteries from the factory are discharged to zero. This is done for transportation safety, so that nothing explodes.
 
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raythompsontn

macrumors 6502a
Feb 8, 2023
592
792
Use the phone, charge the phone, be happy, don't worry about the battery. Perhaps babying your battery might get you two or three extra months. Is that worth the hassle? If you don't have a life, maybe so. My opinion is to just use the device how it best suits you. Ignore the naysayers, ignore my advice, whatever. I update phones every four years, except this year when Xfinity offered me really high trade-in. I have never had an issue with the battery and health and I never concerned myself with the charging.
 

smirking

macrumors 68040
Aug 31, 2003
3,757
3,732
Silicon Valley
The 3 rules you cited are generally good, but not always necessary.

The only one I follow is the 80/20 and I find that's enough to extend the battery life quite well on my laptops. On my phone, I do it out of habit, but I don't know how much difference it's really making. That's because my phone spends most of the day on standby. Its battery isn't under much stress as it is so any attempts to lower the stress on it further is marginal.

I didn't do any battery management on my iPhoneX that I just upgraded from after 5 years. After 5 years and 1500 cycles, it was still at 81%.

It's different on my MBP because the things I do are battery killers so anything I can do to preserve the battery does make a noticeable difference... well it did before I got an M1 Pro. On my Intel MBPs, I'd expect to need a new battery every 1.5 years.
 

JPack

macrumors G5
Mar 27, 2017
12,668
23,570
20/80 is a myth. Discharging to zero is a big no-no however.
There is no point worrying about battery max capacity (incorrectly named Health) dropping by a few percent if you are only ever going to use 60% of it at any time. May as well have 60% health.
I say charge every night all night on slow charge because
1. Optimised charging in most iPhones plus 5watt charger will prevent overheating and
2. Housekeeping events like photos curation need the phone to be locked, on Wi-Fi, and on charge and
3. All the time it is on charge it cannot discharge.
Heat, and usage (discharge), are the main factors affecting ageing.

Not sure why people call it a myth. There has been plenty of studies done on LCO Li-ion cells, the same type used in iPhone and most other mobile phones. The evidence is clear. 80/20 is the most practical rule to achieve battery longevity.

1704659871708.png

 
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raythompsontn

macrumors 6502a
Feb 8, 2023
592
792
Not sure why people call it a myth
I never said stated the 80/20 was a myth. Tesla basically says the 80/20 is the best option. For the cost of a Tesla battery pack getting the most out of the system is important.

My assertion is why worry about it for a phone? Most people change every two, three, or four years. In that time the difference in battery performance is trivial. For those that go new every year, or new version, ”use it like you stole it”. Even after five years the value of the phone is low. At that point a person is better off getting a new phone for the features and OS support.

Fretting over battery charge of 80/20 level is just silly on a phone.
 

Mr.Fox

macrumors regular
Oct 9, 2020
157
85
Not sure why people call it a myth. There has been plenty of studies done on LCO Li-ion cells, the same type used in iPhone and most other mobile phones. The evidence is clear. 80/20 is the most practical rule to achieve battery longevity.

View attachment 2333866

For reference, the iPhone has lithium polymer batteries, which do not like charging in the cycle of 20-80%. There are also lithium-cobalt based batteries, which are not used because they have a tendency to spontaneous combustion and explosion. And they are also wildly expensive in terms of production ;) Read official sources, not what is written on the fence.
 

JPack

macrumors G5
Mar 27, 2017
12,668
23,570
For reference, the iPhone has lithium polymer batteries, which do not like charging in the cycle of 20-80%. There are also lithium-cobalt based batteries, which are not used because they have a tendency to spontaneous combustion and explosion. And they are also wildly expensive in terms of production ;) Read official sources, not what is written on the fence.

LCO refers to lithium cobalt oxide. It's the battery chemistry used in iPhone for a very long time. Perhaps you can learn more about batteries yourself. :)

If you can point to actual studies like I have instead of random (and wildly incorrect "facts"), that would be appreciated!

 

MacCheetah3

macrumors 68020
Nov 14, 2003
2,123
1,095
Central MN
I’ll rehash a reply I recently posted in another thread.

An iPhone can somewhat mitigate overheating, battery and in general, by temporarily deactivating or strongly limiting one or more functions/components. However, there are situations the device (e.g., iPhone) has no control in preventing damaging conditions, namely high temperatures, for example:


That said, let’s move to Apple’s guidance:

Read this carefully — though I will highlight a couple of things:
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.

Apple said:

Remove certain cases during charging.​

Charging your device when it’s inside certain styles of cases may generate excess heat, which can affect battery capacity. If you notice that your device gets hot when you charge it, take it out of its case first.

Apple said:

Automatic battery health management.​

To reduce battery aging, built-in software and hardware systems are included to manage charging patterns and battery temperature.
  • Optimized Battery Charging and Optimized Charge Limit adapt to your daily usage and preserve your battery lifespan over time. Optimized Battery Charging is available on all platforms as of iOS 13, watchOS 7, and macOS Big Sur. Based on your daily charging routine, it may automatically defer charging to 100% until shortly before you need to use the battery. Apple Watch Ultra can further reduce time spent at high states of charge by learning when to charge to an Optimized Charge Limit and when to allow for a full charge.
  • Charging may pause temporarily while in extreme temperature conditions, and will resume once the battery’s temperature returns to its normal operating range. Starting in iOS 16, you may see a notification appear on the lock screen when charging has paused for this reason. Starting in iOS

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.
Basically, with current tech, a battery is most comfortable at 50%, when the chemical pressures are equalized. Of course, it’s impossible to keep battery cells at 50% as that would prevent a battery’s operation.

During charging, lithium ions flow from the positive electrode to the negative electrode through the electrolyte. During discharging, the ions flow back through the electrolyte from the negative electrode to the positive electrode.
how-lithium-ion-batteries-work.gif


What about the 20-80%, 40-60%, and similar recommendations?

They’re mostly arbitrary compromises to prevent exposing batteries to “extremes” (i.e., deep discharge and overcharge). The other problem is when these ranges become more than helpful suggestions and are falsely proclaimed as absolute fact. The truth is battery charge states nearest to zero and one-hundred-percent are stressful on a battery. However, the ‘damage’ is related to amount of time at the edges of the range, where brief periods in the extremes is likely to have negligible impact to rate of degradation. That is why Apple insists you store an iPhone at half-charge and has implemented Optimized Battery Charging:
Apple said:
Optimized Battery Charging is designed to improve the lifespan of your battery and reduce the time your Mac spends fully charged.
The words “and reduce” probably should be “by reducing” but that’s somewhat nitpicking.

Furthermore, another reminding statement, correcting misinformation:

Routine calibration is beneficial (even though it will still never be able to create a perfect gauge):


 
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P_Watt

macrumors regular
Dec 10, 2018
240
152
Not sure why people call it a myth. There has been plenty of studies done on LCO Li-ion cells, the same type used in iPhone and most other mobile phones. The evidence is clear. 80/20 is the most practical rule to achieve battery longevity.
Theres a certain dichotomy with trying to keep capacity above 90% for several years if you will only ever use 60% of it (80-20) between charges.
 

Sorinut

macrumors 68000
Feb 26, 2015
1,670
4,557
Use the phone, charge the phone, be happy, don't worry about the battery. Perhaps babying your battery might get you two or three extra months. Is that worth the hassle? If you don't have a life, maybe so. My opinion is to just use the device how it best suits you. Ignore the naysayers, ignore my advice, whatever. I update phones every four years, except this year when Xfinity offered me really high trade-in. I have never had an issue with the battery and health and I never concerned myself with the charging.

Agreed, people just are just looking for something to fiddle with or worry about. Use your phone how you want, charge when you need, replace the battery when it's time.

Simple.
 

smirking

macrumors 68040
Aug 31, 2003
3,757
3,732
Silicon Valley
Agreed, people just are just looking for something to fiddle with or worry about. Use your phone how you want, charge when you need, replace the battery when it's time. Simple.

I generally agree that most people here are overthinking *everything* but I think the "just use your device" doesn't work if you have a history of murdering your batteries. If you're one of those exceptions, your usage pattern probably has something to do with it. For those people, it's not so simple.
 

Sorinut

macrumors 68000
Feb 26, 2015
1,670
4,557
I think the "just use your device" is perfectly fine advice for most people, but if you're someone who has a history of murdering your batteries, your usage pattern probably has something to do with it. For those people, it's not so simple.

What do you mean by murdering your batteries? I'm at 86% on my 13 Pro and it seems fine; still last a full day plus some.
 
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smirking

macrumors 68040
Aug 31, 2003
3,757
3,732
Silicon Valley
What do you mean by murdering your batteries? I'm at 86% on my 13 Pro and it seems fine; still last a full day plus some.

Some people do things that are very taxing on batteries. If your batteries rarely die prematurely, just use your devices and don't worry. It's like how you drive a car. Some people drive their cars very hard by habit and most people just drive it to get somewhere.

I just traded in an iPhone X that was at 81% after 5 years. I didn't do much battery management other than not letting it go to zero. I don't kill phones. I do kill laptops though and absolutely do need to pay some attention to how I'm working the battery on laptops... though it's much less of a concern since I have an M1 Pro now.

It does make a very significant difference if you're one of those people who puts real strain on your devices.
 
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