Battery calibration is a myth. At least, it may as well be these days. It’s a relic of recommendations for older, nickel-based batteries. But the battery on your iPhone or iPad uses lithium-ion, and calibrating it is not a good idea.
When we talk about calibrating a battery, we mean charging it all the way to 100% then draining it down to zero. The idea is that doing this teaches your iPhone, iPad, or iPod how much power the battery can hold, allowing your device to make the most of it.
There was a time when Apple recommended calibrating your device’s battery every month. They don’t anymore.
These days, it’s not only unnecessary to calibrate the battery in your iPhone, iPad, or iPod, it’s downright damaging to do so.
What’s wrong with calibrating the battery in an iPhone, iPad, or iPod?
To understand why it’s a bad idea to calibrate your iPhone, iPad, or iPod you need to know a little bit about the lithium-ion battery inside it.
iPhone, iPad, and iPod touch devices all use lithium-ion batteries.
Your battery has a lifespan
Every battery has a lifespan. At the beginning of that life, it stores a full charge, which we refer to as its maximum capacity. As the battery ages, its maximum capacity gets smaller and smaller compared to when it was new. Eventually, that battery will die.
But eventually, those batteries will die. They all do.
After a few years of use, the maximum capacity of my iPhone 6S battery reduced to 74%.
What is a charge cycle?
One charge cycle refers to using 100% of your battery’s capacity, but you don’t need to use it in one go. If you drain your battery from a full charge to 50%, that equals half a charge cycle. You need to do it twice to use up an entire charge cycle.
There’s no need to fully charge your iPhone, iPad, or iPod. And there’s no need to drain it all the way to zero before plugging it in again. Apple’s advice is to, “Charge your Apple lithium-ion battery whenever you want.” Let the charge cycles work themselves out.
Your battery doesn’t like extremes
So the lithium-ion battery on your iPhone or iPad is going to age as you use it. That’s impossible to avoid. What’s not impossible to avoid are the extreme situations we can put our devices in that rapidly speed up the aging process.
I’m referring to extreme charge levels and extreme temperatures. Your battery doesn’t like either of them.
What is an extreme charge level?
“Extreme charge level” refers to either 100% or 0% charge. When a lithium-ion battery spends too long at 100% charge, it reduces the maximum capacity of that battery. And when a lithium-ion battery reaches absolute zero, it holds a charge again.
It’s bad for battery health to leave your device without power.
Apple designs its software to include a buffer around the battery. So, when your device says the battery’s at 100% charge, it isn’t really. It stops charging before it gets that far.
Similarly, when your iPhone, iPad, or iPod turns off because the battery died, there’s actually still a bit of charge left in it. That’s how it displays a low power icon when you try turning it back on.
As the charge level drains even more the low power icon stops appearing, but Apple still left a buffer in there. If you leave your iPhone or iPad without power for long enough, the charge eventually reaches absolute zero. And then your battery’s done for.
What is an extreme temperature?
The lithium-ion battery in your iPhone or iPad is happiest between 32° to 95° F (0° to 35° C). When the ambient temperature around your device gets hotter than 95° F or colder than 32° F, then we class it as an extreme temperature.
Your device tries to protect itself by turning off in extreme temperatures. I once found myself in -20° F and my iPhone powered itself off every 20 seconds, leaving just enough time to snap a picture. But even then, my battery life never recovered.
Apple says your device can withstand more extreme temperatures when turned off in storage.
How does this relate to calibrating my iPhone or iPad battery?
Generally speaking, when people try to calibrate their iPhone, iPad, or iPod battery they do a lot of these things lithium-ion batteries don’t like.
To start, they leave it on charge long after it reaches 100% in an effort to squeeze as much power into the battery as possible. Not only does the battery dislike such a high charge for a long period of time, but you run the risk of overheating your device.
Some folks choose to burn through their device’s battery as fast as possible.
People do this by brightening the screen, turning on the flashlight, and playing videos on a loop. It’s a painful waste of one of your limited charge cycles.
When the iPhone, iPad, or iPod finally runs out of power, the user may even leave it without power for as long as possible. The thinking behind this is to discharge the device as much as you can before plugging it in again.
Unfortunately, each step in this calibration process is working to shorten the lifespan of your iPhone, iPad, or iPod battery, not lengthen it.
It is not necessary or even desirable to calibrate your iPhone battery once a month!
It used to be that draining your iPhone’s, iPad’s, or iPod’s battery all to 0% and then charging up to 100% was a good and Apple recommended practice. But no more! Apple has not recommended that users calibrate their batteries for several years now.
In fact, the best approach is to charge your iDevice fully, once per day.
So then, why do people still recommend calibrating my iPhone or iPad battery?
People recommend calibrating your iPhone or iPad battery due to simple misunderstandings. Ten years ago, Apple gave the same recommendations.
They advised users to fully charge and discharge their battery at least once a month. It made sense to think about it: You want to keep your battery active, so use it or lose it!
What’s more, many people use battery calibration as a solution to software problems: unexpected shutdowns, incorrect battery readings, or unreliable charge cycles. These can all be fixed by restoring your device, without damaging the health of your battery.
The facts are simple: Technology has moved on, and so should we.
What about all the personal anecdotes
While people still tout the benefits of battery calibration, personal anecdotes are not a reliable measure.
Did any of these people run a scientifically accurate test? Did they buy a second, control device to use without battery calibration for comparison? Did they ensure there weren’t other external factors contributing to prolonged battery life?
You can be certain that Apple ran those tests. And you can be certain that if they discovered it was a good idea to calibrate your iPhone, iPad, or iPod battery that would still be their recommendation. But it isn’t.
And Apple isn’t alone on this. Google, Samsung, and other smartphone manufacturers also advise against fully charging and draining your battery on a regular basis!
Samsung offers a lot of other power-saving tips on its website as well.
How do I maintain the health of my iPhone or iPad battery?
Without calibrating the battery in your iPhone, iPad, or iPod, there are still lots of other things you can do to maintain a healthy battery life. You probably do some of these things already, without realizing it’s good for your battery.
When you keep your device updated, you always benefit from the latest advancements. To update your iPhone, iPad, or iPod, connect to the Internet and select Software Update from the General settings.
2. Keep your device at a comfortable temperature
Of course, we can’t change the weather, but it’s good to be aware of what we can do to keep our devices away from extremely hot or extremely cold temperatures. Even being aware of the risk might make you second guess leaving your phone out in the sun.
One common problem for users is that their device overheats while charging. This can be the result of using unofficial power adapters and charging cables. Try to use the ones that came with your device, or at least make sure they’re MFi certified.
Also, consider removing your iPhone or iPad from its case while charging. Plenty of poorly designed cases don’t allow enough airflow to keep the device cool.
Finally, if using wireless charging, make sure to place your iPhone in the center of the charging pad. When it’s off-center the technology has to work a lot harder, often resulting in overheating and long-term damage to your battery.
3. Don’t charge or discharge your battery all the way
If you can help it, don’t let charge your battery die. Similarly, only charge to 100% when you actually need the extra battery life that day. Both of these extreme charge levels take a toll on your battery and shorten its lifespan.
This is exactly why it’s a bad idea to calibrate your iPhone, iPad, or iPod battery.
Your iPhone, iPad, or iPod is happiest with about 50% charge, not too much and not too little. If you aren’t planning to use your device for a long time, charge or drain the battery to 50% before you store it.
You shouldn’t leave the battery at 100% charge for a long period of time because the pressure of it reduces the maximum capacity. And if you store your device with a low charge you run the risk of it draining to absolute zero, also not a good idea.
I think many of us dream of an age where all our devices are waterproof, and although we’re getting close to that fantasy, we aren’t there yet. Since the iPhone 8, every new iPhone from Apple has been water-resistant. But that isn’t the same as waterproof.
A water-resistant device can still suffer liquid damage. If you can help it, keep your devices out of the rain and certainly don’t go swimming with them. Liquid damage is very bad for almost every component in your device, particularly the battery.
6. Try to use less power in general
Find out what’s using the most power from your Battery settings.
Our final suggestion is much easier said than done: Use less power.
With every charge cycle, the battery on your iPhone, iPad, or iPod has a little bit less life in it. The absolute best thing you can do to prolong your battery life is to find ways to use less power. We’ve included a few suggestions for how to do this below.
Of course, this is all about compromise. It means changing your habits and possibly turning off some of the features you like on your device. Not everyone has to follow all the suggestions below, but any of them could help sustain your battery life.
The simplest way to use less power is to put your device down more often. But other than that, try any or all of the suggestions below.
Turn down the screen brightness
The display is one of the most power-hungry parts of your device. You can do a lot to save energy by turning down the brightness. This is easy to do from the Control Center or the Display & Brightness settings.
We also recommend turning on Auto-Brightness if you haven’t done so already. Open the Settings app and pull down to reveal a Search Bar, type in “Auto-Brightness” to find it in the settings.
Use Wi-Fi instead of cellular data
Wi-Fi is becoming more and more prominent, which is great for the battery-conscious because it uses less power than cellular data. Whenever possible, connect to a Wi-Fi network instead of using cellular data.
You might even be able to switch to a cheaper cell contract as a result of using less data.
Reduce your notifications
Your screen lights up every time a notification comes in, whether you look at it or not. Considering lots of us get upwards of 50 notifications a day, this can be an enormous drain on power!
Take a look through your Notification settings and turn off Lock Screen notifications for as many apps as possible. Of course, you probably still want it for some stuff, but try to keep it to the essentials.
Enable Low Power Mode
Low Power Mode tweaks a handful of settings to use less power on your device. You don’t need to wait until there’s only a 20% charge left use it. In fact, if you turn Low Power Mode on at the start of every day, you might never reach that 20% point.
Turn Low Power Mode on from the Battery settings or add a button to Control Center for easier access. You can even ask Siri to do it for you.
Turn off Background App Refresh
Background App Refresh is a feature that allows apps to keep running in the background so they can display updated content and open more quickly. As you may expect, this is great for convenience but not so great for your battery.
This is one of the settings Low Power Mode already turns off but you can also permanently turn it off. Open the Settings app and drag down to reveal the Search Bar. Type “Background App Refresh” to find the feature and turn it off.
Turn on Reduce Motion
Your iPhone, iPad, or iPod uses lots of subtle animations to create a slick and fluid experience when using the device. This includes things like the parallax effect on your wallpaper or the way app folders swoosh out when you open them.
Although you may never notice these features, they still drain your battery. Open Settings and search for Reduce Motion to turn the animations off and save power. You might not even notice a difference!
Check your battery usage
It’s always useful to find out what apps are using the most power on your device. You can do this at any time from the Battery settings on your iPhone, iPad, or iPod.
From here you can see a breakdown of how your battery was used in the last 24 hours or over the last ten days. Closely examine each app in the list to decide if it’s worth keeping, considering how much battery power it uses up.
What’s the best way to charge my iPhone, iPad, or iPod?
Using a wireless charger to top up your charge when you need it is a good alternative to calibrating the battery.
Apple’s advice is still to charge your device whenever you want, for as long as you want. Lithium-ion batteries are more flexible than previous generations of battery technology, so you don’t need to worry about them as much.
That said, if you really want to maintain your battery lifespan, you might consider charging your device little and often rather than plugging it in overnight. Wireless charging mats are particularly good for this because they’re so convenient to use.
Our batteries are happiest at a medium charge level, around 40–60%. The closer you keep it to that range the better it’s going to be for your battery lifespan.
For most people, living in the 40–60% zone isn’t very practical. And if you do this, you also need to make sure your device still updates and backs up to iCloud regularly. Since those actions are usually reserved for overnight charging.
Whatever route you choose to take, don’t make a habit of calibrating your iPhone, iPad, or iPod battery.
What about Optimized Battery Charging in iPadOS and iOS 13?
For example, if you normally charge your iPhone from 22:00–06:00 every night, then it isn’t good for the battery to get to 100% as quickly as possible then sit for another six hours.
With Optimized Battery Charging, your iPhone waits at an 80% charge until the last hour before you normally use it. This is much better for battery life since too much time spent at 100% reduces your maximum capacity.
If you have iPadOS or iOS 13, turn the feature on in the Battery Health section of your Battery settings. A notification appears on the lock screen when you’re using Optimized Battery Charging. You can tap this notification at any time to turn it off.
A notification tells you when your device is scheduled to finish charging.
Do you still plan to calibrate the battery on your iPhone, iPad, or iPod? I certainly don’t after researching for this post! Let us know your thoughts in the comments, and feel free to share your own tips and tricks for maintaining the battery life of your devices.
Dan writes tutorials and troubleshooting guides to help people make the most of their technology. Before becoming a writer, he earned a BSc in Sound Technology, supervised repairs at an Apple Store, and even taught English in China.
Hi Dan, I am an electronics engineer so I feel qualified to make some comments. Generally in a perfect world I can agree with most of your recommendations, which are aligned closely to Apples, but lets talk about a real life issue with a second hand phone I recently bought. Without doing scientific research and proof here goes; the battery health said 81%. After a full recharge, the phone dropped from 100% to 50% in 12 hours then a few hours later it was on 13% – it has no sim card and the screen was only on for a few seconds to check battery % life remaining. Next I turned on the display to full brightness and watched the % meter quickly drop from 13% down to 1%. I reduced the brightness to ~ 75% and it has been running like that now for well over an hour at 1% – I am expecting many more hours like this at the “1%.”
In cases like this where the battery charge % remaining indicator is lying to you there are not a lot of options. I will follow the process of doing two cycles of a full discharge (when the lights actually go out not just when it reaches 1%) followed by a full charge to 100% (I will use a mains power meter to prove that it is no longer drawing a charging rate). After I reach the second 100% charge I expect that the correct battery % meter will read properly – some suggestions say if there are still issues a warm reboot after the second 100% is reached made it read correctly – I will do this if needed. It is not acceptable for the phone to remain at nearly full brightness when the meter reads 1% for well over two hours so far. Your advice might be good advice for someone who is experiencing genuine shorter battery life but for my issue – I don’t need a new battery, it runs for many hours longer than when the indicator says 1% remaining I just need the correct % remaining reading to be displayed.
Good Idea, but if you have replaced a battery yourself or you are out of warranty it makes sense to try recalibration first, if still not resolved replace the battery. Recalibration is necessary if your battery is out of sync with your phone or you are experiencing strange battery behaviour that has not improved with time or with a system reset
I have an iPhone 11 Pro and until the last week or two, the Optimized Battery Charging feature worked quite well. Then all of a sudden, I would plug it in before going to bed (around 10) and by midnight, it would charge all the way to 100%. I would no longer get a notification to tell me that it was scheduled to finished charging by 5 or 6 a.m. I have called Apple on this issue and we are now in the process of seeing what can be done. I have read other comments on other sites of people saying that this feature is also not working on their phone. Apple needs to figure out a solution!
The debate continues in the comments! I just did the whole calibration procedure with my old iPhone SE 16GB which I now only use as an iPod only. Anyway, the battery health is still good, I don’t think I ever calibrated it before, but when I used it as a cellphone before getting a newer iPhone the battery wasn’t the best especially with gps apps in use. As an iPod, it’s a lot better battery life, no gps apps in constant use or cellular.
I got the battery replaced on my other/newer/refurbished iPhone 8 last year and the Apple repair shop I went recommended doing a battery calibration on the brand new battery. So even Apple repair places still recommend it, (I didn’t go to the Apple store) though they didn’t give any recommendations to do it every month or even every few months, it would be a PITA to do it that often. I can see doing it that often could cause issues. But every few years can’t hurt, or if it’s showing issues with the percentage.
Battery calibration makes sense, rather than it being just a myth.
I’ve had my iPhone 6S Plus since December 2015, last year I noticed it having significantly lower battery life and it seemed like the battery percentage was inaccurate, it would jump from 100 to 82 in a few minutes of use but would stay at 82 for hours.
It’s battery health said “Service” and was at 74% maximum capacity.
74% maximum capacity coupled with the fact that the battery percentage was inaccurate, I opted to replace it.
Even after replacing though battery percentage was inaccurate, albeit its maximum capacity was at 100%.
Charge the device to 100% and keep charging it for at least 2 additional hours
Use your device until it automatically shuts off due to low battery
Charge it uninterrupted to full capacity 100%.
It seemed to do the trick, now at 100% maximum capacity and my battery percentage is accurate.
So, how do you resync the battery level reading software with an actual battery charge?
I have an iPhone 5S running iOS 12.4.
As the battery approached 50%, sometimes 62%, the phone would shut down, remain unresponsive until plugged in and when plugged in, after rebooting, would show near 50% charge after only a couple of minutes of charge.
Recalibration has improved both the time between charges as well as the ability to read charge states below 50%. Recalibration works for me.
Hi, a Google search brought me here: my iPhone (IOS13) battery meter quickly moves from 100% down to 1% (in the space of a few hours). Then it stays at 1% for 10 – 15 hours before eventually powering off.
I have read your article and now understand going from 100% to 0% is not good for my battery.
But how do I ‘calibrate’ the meter so it more accurately displays the true available capacity of the battery?
Take a look at your battery health metrics via Settings > Battery > Battery Health. Look at the number next to Maximum Capacity and read the message below Peak Performance Capability.
If everything there indicates your battery is fine, try toggling off Optimized Battery Charging.
If things indicate a battery issue, contact Apple for its battery service to replace your battery. If your iPhone is in its warranty period, the replacement service is free. If not, it costs between $49-$69 USD to replace it.
Yeah, just buy a new battery. Don’t bother calibrating your iPhone, because you could break your, um, failing battery… Don’t even give it a try. Just hand over your money to Apple!
Hi Dan, I am an electronics engineer so I feel qualified to make some comments. Generally in a perfect world I can agree with most of your recommendations, which are aligned closely to Apples, but lets talk about a real life issue with a second hand phone I recently bought. Without doing scientific research and proof here goes; the battery health said 81%. After a full recharge, the phone dropped from 100% to 50% in 12 hours then a few hours later it was on 13% – it has no sim card and the screen was only on for a few seconds to check battery % life remaining. Next I turned on the display to full brightness and watched the % meter quickly drop from 13% down to 1%. I reduced the brightness to ~ 75% and it has been running like that now for well over an hour at 1% – I am expecting many more hours like this at the “1%.”
In cases like this where the battery charge % remaining indicator is lying to you there are not a lot of options. I will follow the process of doing two cycles of a full discharge (when the lights actually go out not just when it reaches 1%) followed by a full charge to 100% (I will use a mains power meter to prove that it is no longer drawing a charging rate). After I reach the second 100% charge I expect that the correct battery % meter will read properly – some suggestions say if there are still issues a warm reboot after the second 100% is reached made it read correctly – I will do this if needed. It is not acceptable for the phone to remain at nearly full brightness when the meter reads 1% for well over two hours so far. Your advice might be good advice for someone who is experiencing genuine shorter battery life but for my issue – I don’t need a new battery, it runs for many hours longer than when the indicator says 1% remaining I just need the correct % remaining reading to be displayed.
Good Idea, but if you have replaced a battery yourself or you are out of warranty it makes sense to try recalibration first, if still not resolved replace the battery. Recalibration is necessary if your battery is out of sync with your phone or you are experiencing strange battery behaviour that has not improved with time or with a system reset
I have an iPhone 11 Pro and until the last week or two, the Optimized Battery Charging feature worked quite well. Then all of a sudden, I would plug it in before going to bed (around 10) and by midnight, it would charge all the way to 100%. I would no longer get a notification to tell me that it was scheduled to finished charging by 5 or 6 a.m. I have called Apple on this issue and we are now in the process of seeing what can be done. I have read other comments on other sites of people saying that this feature is also not working on their phone. Apple needs to figure out a solution!
The debate continues in the comments! I just did the whole calibration procedure with my old iPhone SE 16GB which I now only use as an iPod only. Anyway, the battery health is still good, I don’t think I ever calibrated it before, but when I used it as a cellphone before getting a newer iPhone the battery wasn’t the best especially with gps apps in use. As an iPod, it’s a lot better battery life, no gps apps in constant use or cellular.
I got the battery replaced on my other/newer/refurbished iPhone 8 last year and the Apple repair shop I went recommended doing a battery calibration on the brand new battery. So even Apple repair places still recommend it, (I didn’t go to the Apple store) though they didn’t give any recommendations to do it every month or even every few months, it would be a PITA to do it that often. I can see doing it that often could cause issues. But every few years can’t hurt, or if it’s showing issues with the percentage.
Apple just doesn’t want people fixing their batteries themselves because they would rather customers just waste money on a new one.
Apple’s only interested in profit. Calibration is a NOT myth.
I work in an IT office and I’ve performed multiple calibrations on lithium-ion batteries.
Battery calibration makes sense, rather than it being just a myth.
I’ve had my iPhone 6S Plus since December 2015, last year I noticed it having significantly lower battery life and it seemed like the battery percentage was inaccurate, it would jump from 100 to 82 in a few minutes of use but would stay at 82 for hours.
It’s battery health said “Service” and was at 74% maximum capacity.
74% maximum capacity coupled with the fact that the battery percentage was inaccurate, I opted to replace it.
Even after replacing though battery percentage was inaccurate, albeit its maximum capacity was at 100%.
Then I found a page on battery calibration at iFixit,
Charge the device to 100% and keep charging it for at least 2 additional hours
Use your device until it automatically shuts off due to low battery
Charge it uninterrupted to full capacity 100%.
It seemed to do the trick, now at 100% maximum capacity and my battery percentage is accurate.
So, how do you resync the battery level reading software with an actual battery charge?
I have an iPhone 5S running iOS 12.4.
As the battery approached 50%, sometimes 62%, the phone would shut down, remain unresponsive until plugged in and when plugged in, after rebooting, would show near 50% charge after only a couple of minutes of charge.
Recalibration has improved both the time between charges as well as the ability to read charge states below 50%. Recalibration works for me.
Hi, a Google search brought me here: my iPhone (IOS13) battery meter quickly moves from 100% down to 1% (in the space of a few hours). Then it stays at 1% for 10 – 15 hours before eventually powering off.
I have read your article and now understand going from 100% to 0% is not good for my battery.
But how do I ‘calibrate’ the meter so it more accurately displays the true available capacity of the battery?
Hi James,
Take a look at your battery health metrics via Settings > Battery > Battery Health. Look at the number next to Maximum Capacity and read the message below Peak Performance Capability.
If everything there indicates your battery is fine, try toggling off Optimized Battery Charging.
If things indicate a battery issue, contact Apple for its battery service to replace your battery. If your iPhone is in its warranty period, the replacement service is free. If not, it costs between $49-$69 USD to replace it.
Yeah, just buy a new battery. Don’t bother calibrating your iPhone, because you could break your, um, failing battery… Don’t even give it a try. Just hand over your money to Apple!
Now I see the motive…