iPhone Battery Health, Service, Calibration

Never let it discharge to 0%. No need to turn off any WiFi, Data or anything else. Just let is charge to the full 100% for several charge charges over a couple of weeks. Preventing it from charging to 100% will stop it from Calibrating. I am currently on iOS 18.3 and you are not doing yourself any favors by not updating from iOS 18.2. When you have a free half hour, just update it and let it do its thing while it is plugged into power.

If you still see the same message in the Battery Settings showing after several weeks of charging, then take it to Apple for a free diagnostic. Some important points in the Apple Support article dealing with Calibration is here in addition to the message you would see if Recalibration is not successful:

• If the recalibration of battery health reporting indicates that your battery health has significantly degraded, the battery service message will appear.
• While the battery health reporting system is recalibrating, you will see a message in Settings > Battery > Battery Health. Recalibration of maximum capacity and peak performance capability happens during regular charge cycles, and this process might take a few weeks.

About recalibration of battery health reporting in iOS 14.5 or later - Apple Support

Battery Calibration occurs when it is allowed to charge to 100% over several battery cycles, so do not prevent it from charging up fully and wait to see if the message goes away and gives you the actual Maximum Capacity. Coconut Battery simply reports the same value that the iPhone is telling you what it is. It would not be unusual for an iPhone 11 to need a battery replacement, and it may have degraded to the point where it cannot calibrate.

Switch the phone off or let it power down, if the battery state has switched the phone off. If you can switch it into lower power mode prior to it switching off, all the better. Connect and appropriate charger to the connection point, don’t use contact charging. As they don’t communicate properly with the battery maintenance circuitry built into the device.

Once the battery reaches a level that it can power the device, disable wifi and data- airplane mode. And allow it to charge from low power mode for at least 8 hours. Or until the battery reaches 100%. Then let it charge on for as long as possible, to further enable the maximum amount of battery maintenance cycle.

As the basic percentage indicator for the battery doesn’t observe or indicate the actual charging mode that the internal charging circuitry has implemented. Ideally it would have been switched into refresh charge. Slow rate charge with cell balancing. To restore discharge level to individual battery cells. If you observe the charge status while it’s charging you should see a message stating it’s doing such a maintenance charge. Provided you have it enabled under battery, in settings. And you may notice that the charge percentage indicator stays at about 80 for quite a while after it may have reached that number comparatively quickly. Unless it’s ( the phone), had an update which had possibly removed that status indicator. Which may even indicate that the maintenance charge feature has also gone. Unfortunately, this is why i advocate against rushing into ios updates if you don’t feel you need them. At the moment ios 18.1, still seems to have this battery maintenance feature. And from my knowledge of lithium type batteries and proper maintenance, the function availability incorporated into the phone charging system isn’t ideal but would certainly benefit to try and familiarise with the working process.

As a quide i should also add that in general it helps the ‘battery health’ to allow the percentage level to drop to about 37% before placing it on charge as much as you could implement in your charging routine. Baring in mind that contact charging isn’t ideal, as the format doesn’t properly enable maintenance charging process sequences

I wouldn’t speak in favour of what the next update brings. Which according to (many) other user advisers, doesn’t seem positive in general.

I hope that seems clear enough and worth familiarising . As there is a lot to understand about development in lithium based battery, charging technology.

You're welcome to keep the phone. Worst case, you may have to have the battery replaced.

Wait for the recalibration to complete and see what it says.

“An update won’t improve battery status or health. If anything it could make it worse. I wouldn’t suggest doing an update while the battery seems unreliable either. The phone could end up bricked, as the update would be interrupted.”

It won’t improve battery health, its health is what it is. However, iOS updates may contain firmware updates that combine can lead to more accurate measurements due to refined and more accurate algorithms and firmware to modify charging dynamics.

Overcome the bricking by leaving it plugged in during updates.

There have been four iOS updates released since iOS 18.2.

Update your iPhone or iPad - Apple Support

20%should ideally never be reached. And shouldn’t need to be. Although a lot of times people find it unavoidable. Which leads me to point of that the built in battery health maintenance system is in fact lacking. As it should power down the device at - ideally between 36%-42% Lithium based batteries should never be allowed to fall below 50%. Depending on routine usage. And a battery should niether be left in storage at above 60%. Just to put your thoughts in the right place.

cMac_Knoxville wrote:

We've already completely discharged the battery to 0%

You should never do this on an iPhone or iPad. Try to keep at least a 20% charge at all times.

An update won’t improve battery status or health. If anything it could make it worse. I wouldn’t suggest doing an update while the battery seems unreliable either. The phone could end up bricked, as the update would be interrupted. It happened to my SE 2. And it is a warning prior to any update.

For your information my XS still holds decent charge, although the battery health is indicated at 75%. And i don’t agree with what you state about’Cocunut’. The battery health is as it implies- it gives an indication which is a basically averaging out the battery level at which your phone is put on charge. So in fact shouldn’t even be referred to as battery health of course. Coconut monitors more information like discharge rate vs battery capacity and voltage level at it’s given discharge rate. And would also incorporate cell monitoring. If you don’t know what battery technology and proper maintenance involves you’re giving false information. Clearly you don’t understand what an additional app would be implemented to perform. And information it would provide in this circumstance.

The original poster never said the battery is unreliable. Updates do cause some additional battery use for a short time, but provide additional security, defect repair, and occasionally functionality.

croloriarc295 wrote:

And allow it to charge from low power mode for at least 8 hours. Or until the battery reaches 100%.

Low Power Mode turns off when the device is at 80%, usually. So you can’t charge with Low Power Mode on until 100%.

As there is a lot to understand about development in lithium based battery, charging technology.

Can I ask where you got your education on this topic from?

Oh and why is Wireless Charging not ideal? Can you clarify on that? (If that’s what you mean by “contact charging.”)

“Switch the phone off or let it power down, if the battery state has switched the phone off. If you can switch it into lower power mode prior to it switching off, all the better. Connect and appropriate charger to the connection point, don’t use contact charging. As they don’t communicate properly with the battery maintenance circuitry built into the device.”

Do you have a source for your claims and statements? Just a link that substantiates what you’re claiming?

You’re claiming as fact, statements you can’t provide any evidence for.

croloriarc295 wrote:

For your information my XS still holds decent charge, although the battery health is indicated at 75%.

You are simply getting 75% of the usable battery that you had when it was new. That is fine if a "decent" charge works for you. Eventually it will kick on the Peak Performance Monitoring to manage the performance of your device to prevent shutdowns due to the degradation of your battery.

I hope you’re not trying to contribute irrelevant statements to my authority on battery maintenance systems. For one- reference to ios 14. from advice through a link would certainly be dated and insignificant. And advising the procedure of updating from an ios to the next is just as dated. Clearly you seem to misunderstand that aged devices can only operate to a certain level of ios. I regularly use my old six S as another contact option, it’s running 15.4 and apparently can’t receive further ios updates. Although it functions well as this XS i use. So once again the point of ios updates is dubious

Would you really want to imply that such a simple (well guided) process as updating - via the basic update availability, highlighted in settings; needs additional ‘advice’- from an individual with your common insight.

And it’s always advisable to limit usage on any process while a battery is charging. Particularly your iphone if you have background app refresh enabled, with most of your apps. Do you know what background app refresh means I wonder.

[Edited by Moderator]