Comments on: Why you shouldn’t calibrate the battery in your iPhone, iPad, or iPod

By: Mike R

Mike R — Mon, 13 Dec 2021 01:21:02 +0000

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.

By: Chris

Chris — Wed, 09 Dec 2020 11:16:01 +0000

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

By: Elizabeth Moore

Elizabeth Moore — Thu, 01 Oct 2020 00:52:30 +0000

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!

By: Kim Jun Hecklesbirth

Kim Jun Hecklesbirth — Fri, 29 May 2020 09:11:19 +0000

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.

By: Angel

Angel — Fri, 20 Mar 2020 16:35:45 +0000

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.

By: Appledystopia

Appledystopia — Fri, 13 Mar 2020 21:39:11 +0000

In reply to Elizabeth Jones.

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…

By: Dan

Dan — Fri, 14 Feb 2020 05:11:12 +0000

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,

uninterrupted

It seemed to do the trick, now at 100% maximum capacity and my battery percentage is accurate.

By: Ron

Ron — Tue, 12 Nov 2019 21:19:27 +0000

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.

By: Elizabeth Jones

Elizabeth Jones — Tue, 12 Nov 2019 16:48:58 +0000

In reply to James.

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.

By: James

James — Tue, 12 Nov 2019 10:11:40 +0000

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?