iPhone XR Battery capacity fluctuating, is this normal?

Stuey3D

macrumors 6502
Original poster
Jul 8, 2014
436
404
Northamptonshire, United Kingdom
Hi all

I have noticed something a bit odd with my iPhone XR battery capacity when using Coconut Battery.

I decided to use Coconut battery as my iPhone has dropped to 99% capacity according to iOS after a exactly a month of ownership. I thought this might have been excessive so decided to dig further.

The other day I plugged into Coconut battery and it showed:

36 Cycles
Design Capacity 2942mAH
Current capactiy 2940mAH
99.9% healthy

Today I plugged it in and something weird has happened I have gained capacity. Now it is showing:

38 Cycles
Design Capacity 2942mAH
Current Cpacity 2962mAH
100% healthy.

In iOS I am still showing as 99% healthy.

For comparisons sake I plugged my wife’s XR in as she got hers exactly the same time as me, although hers doesn’t get used as much as mine and hers is reading:

28 Cycles
Design Capcity 2942mAH
Current capacity 2982mAH
100% healthy.

Is it normal for the battery capacity to fluctuate a little bit like this? Is it a case of temperatures and amount of use in a day that may cause this, and is this normal for now 6 weeks of ownership?
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
In opinion it is a sign of a low quality battery but that's what we get for the price these days.
I've similar issues with my X and also with my previous X, so that battery capacity and voltage fluctuates quite a lot but it has so far stayed above 100% but that really does not mean much since battery does not last so well. We have another X in our family that has very strong battery and its capacity does not fluctuate and voltage also keeps up very well in different loads. Capacity reading in this better one is always the same no matter what charge level of the battery is, while in weaker one capacity reading is almost always different depending on the charge level of the battery. The better one has even higher over percentage over nominal capacity, but as I mentioned capacity reading itself has very little meaning since from what it looks to me is that batteries showing even slight variations and drops seem weaker in practise than those that stay high all the time. So like in our two phone only couple percentage difference in capacity reading equates to that better one has 1 or 2 days more between charges than weaker one, so huge difference with about same SOT.

If you have time compare capacity reading between the two and then also consider actual SOT and standby times and see if you come up with similar results.
 
  • Like
Reactions: BigMcGuire

GGJstudios

macrumors Westmere
May 16, 2008
44,365
703
Is it normal for the battery capacity to fluctuate a little bit like this?
Yes, it's perfectly normal for battery health to fluctuate up and down over time. Battery readings are estimates and are not intended to be 100% accurate. They are, however, close enough to give you a reasonable idea of the health of your battery.
 

now i see it

macrumors 601
Jan 2, 2002
4,138
8,157
CoconutBattery is not reliable. Sometimes it'll tell me my battery is at 65% and later in the day it'll say 95%. When the iPhone is cold it will report a lower capacity (so maybe it is accurate)
 

chabig

macrumors 603
Sep 6, 2002
6,031
3,256
I have noticed something a bit odd with my iPhone XR battery capacity
You are exhibiting obsessive behavior. Just stop fooling around checking battery capacity. I know this will be hard for you but you will live a happier life.
 
  • Like
Reactions: jemcik

BLBL

macrumors 6502a
Apr 11, 2018
758
104
CoconutBattery is not reliable. Sometimes it'll tell me my battery is at 65% and later in the day it'll say 95%. When the iPhone is cold it will report a lower capacity (so maybe it is accurate)
If it is fluctuating that much your battery is likely not reliable. When batteries get older they get more and more depending on the temperature and quickly drop their capacity in cold but if you are referring to normal room temperatures with only some battery temp variation depending on the use of the phone, that much is not healthy battery fluctuation, good ones do not fluctuate much all in such conditions.
 

BigMcGuire

Contributor
Jan 10, 2012
4,681
5,724
California
Normal for batteries to fluctuate, especially in colder weather. I always make a point to record coconutBattery at the same charge percentage - 100%, as this seems to be the most accurate for the battery. I've recorded my 6s+, 8+, and Xs Max over their lifespan and batteries definitely fluctuate.

I mostly pay attention to capacity and charge cycles. Some points to note: Battery wear is not linear, like a tank of gas, it is a chemical reaction that changes. https://www.BatteryUniversity.com is a great place to learn how to care for a battery - the author of the site writes a really good book too.

Here is my 8+ that I had for about a year:
Screen Shot 2019-03-03 at 10.31.18 AM.png
 
  • Like
Reactions: Newtons Apple

Stuey3D

macrumors 6502
Original poster
Jul 8, 2014
436
404
Northamptonshire, United Kingdom
You are exhibiting obsessive behavior. Just stop fooling around checking battery capacity. I know this will be hard for you but you will live a happier life.
Yeah I’m probably been a bit obsessive, however it’s because I had an issue with the 12.2 beta which forced me to DFU back to 12.1.4 and set up as new and even though the phone has less stuff on it the battery to me doesn’t seem to be lasting quite as long.

That said I asked over on the iOS forum and quite a few say that 12.2 is actually better on the battery even though it’s only a beta. So I guess I have nothing to worry about.
[doublepost=1551638253][/doublepost]
Normal for batteries to fluctuate, especially in colder weather. I always make a point to record coconutBattery at the same charge percentage - 100%, as this seems to be the most accurate for the battery. I've recorded my 6s+, 8+, and Xs Max over their lifespan and batteries definitely fluctuate.

I mostly pay attention to capacity and charge cycles. Some points to note: Battery wear is not linear, like a tank of gas, it is a chemical reaction that changes. https://www.BatteryUniversity.com is a great place to learn how to care for a battery - the author of the site writes a really good book too.

Here is my 8+ that I had for about a year:
View attachment 824398
Ahh yes I see quite a bit of fluctuation on that chart, however what is impressive is that it is all above the design capactiy, it almost looks like apple have some sort of battery lottery with a design capacity and some batteries being over it by quite a bit. I guess this is like the silicon lottery with overclocking processors, some can go far higher than others.
 
  • Like
Reactions: BigMcGuire

BigMcGuire

Contributor
Jan 10, 2012
4,681
5,724
California
Ahh yes I see quite a bit of fluctuation on that chart, however what is impressive is that it is all above the design capactiy, it almost looks like apple have some sort of battery lottery with a design capacity and some batteries being over it by quite a bit. I guess this is like the silicon lottery with overclocking processors, some can go far higher than others.
Correct. My 6+ was 108% design capacity. My 6s+ was 96% design capacity. 8+ was a tiny bit over, and my Xs Max is 3301mAh (design is 3156 mAh).

My 2018 iPad is way over design capacity (8800 mAh capacity with a design capacity of 8557 mAh) while my 2017 MBP is right at design capacity.

Interestingly enough, my 6s+ was used for almost 2 years and never dropped % in capacity even after 240+ cycles while my 6+ dropped over 10% with similar usage/time. :p
 
  • Like
Reactions: Newtons Apple

Stuey3D

macrumors 6502
Original poster
Jul 8, 2014
436
404
Northamptonshire, United Kingdom
Correct. My 6+ was 108% design capacity. My 6s+ was 96% design capacity. 8+ was a tiny bit over, and my Xs Max is 3301mAh (design is 3156 mAh).

My 2018 iPad is way over design capacity (8800 mAh capacity with a design capacity of 8557 mAh) while my 2017 MBP is right at design capacity.

Interestingly enough, my 6s+ was used for almost 2 years and never dropped % in capacity even after 240+ cycles while my 6+ dropped over 10% with similar usage/time. :p
I guess manufacturing tolerances have to be taken into account, I bet most batteries have a design capacity under what they actually are.

I bet the 2942 capacity for the XR is a capacity that maybe 99% of the batteries in the factory can achieve with most of them being over slightly, the remaining 1% falling just below and being binned.

It’s the same with most things I guess, my laptop for instance has a GTX1050 and my boost clock is far higher than the design rating and actually slightly higher than most of the benchmark videos I see for it. So with my laptop I got lucky with the silicon lottery.

However back to the battery, my capacity seems to be hovering around the design capacity give or take a few mAH so I think my perceived poorer battery life must be software related going back from 12.2 back to 12.1.4. Maybe the cellular modem firmware was updated and made it more efficient as my battery seems worse on cellular than on 12.2 however when at home on WiFi it seems about the same as before.
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
My 2018 iPad is way over design capacity (8800 mAh capacity with a design capacity of 8557 mAh).
Has it been that high for how many charge cycles? I ask because mine was also at that high for quite some time but then dropped quite fast to around 94% and that show up in running time also. Also mine show in iMazing that design capacity is 8557 which is odd since all the reviews I've seen where they have pulled the battery out it has 8827 stamped on, so obviously they put smaller capacity batteries in some units.

ps. When mine dropped the first time and a lot it was the first time I kept it plugged in for a little longer than about 30 minutes after it has reached 100%, so this is interesting. I actually went thru few iPads before settling with this one due to weak battery right out of the box.
 
  • Like
Reactions: BigMcGuire

BigMcGuire

Contributor
Jan 10, 2012
4,681
5,724
California
Has it been that high for how many charge cycles? I ask because mine was also at that high for quite some time but then dropped quite fast to around 94% and that show up in running time also. Also mine show in iMazing that design capacity is 8557 which is odd since all the reviews I've seen where they have pulled the battery out it has 8827 stamped on, so obviously they put smaller capacity batteries in some units.

ps. When mine dropped the first time and a lot it was the first time I kept it plugged in for a little longer than about 30 minutes after it has reached 100%, so this is interesting. I actually went thru few iPads before settling with this one due to weak battery right out of the box.
It's basically brand new - Purchased 1/13/2019. 10 cycles so far on it. Started out at 8806. I just measured it again today:

Screen Shot 2019-03-03 at 11.06.13 AM.png


I too have noticed the threads on battery life of these iPads. I try to read it as soon as coconutBattery shows fully charged because it will drop after that slowly.

https://www.ifixit.com/Teardown/iPad+6+Teardown/105416

Interesting. You're right, 8827 mAh. https://d3nevzfk7ii3be.cloudfront.net/igi/QW3NGQFjwTjCGIdX.huge
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
I see, yours is still on its early stages. I just checked my notes and mine started at 8996mAh out of the box. Then it hovered around 8800 up to 17 charge cycles but then I forgot to unplug it next time and it was maybe couple hours after it reached 100% and capacity dropped instantly to around 8600mAh and from that on drops were sharp, 22 cycles was already down to 8300. Now it has 82 cycles and only 8051mAh and it show in running time also. iMazing says it is about 94% but obviously counting from 8557, while in reality it is only about 91% counting from supposed 8827mAh. Hard to see that batteries like this will last anything near 500 or was it even 1000 cycles iPad batteries supposed to be rated for? And as a note before anyone even suggest I'm running deep cycles or such causing it to die so soon- I'm not, I never let it run very low and charge it usually when it reach about 40% or so.

I'm also confused about design capacity vs what seen in reviews. Obviously they put different quality batteries in some of these. All iPad's I could get in my hands had 8557 and some were weak right out of the box.
 
Last edited:
  • Like
Reactions: BigMcGuire

BigMcGuire

Contributor
Jan 10, 2012
4,681
5,724
California
I see, yours is still on its early stages. I just checked my notes and mine started at 8996mAh out of the box. Then it hovered around 8800 up to 17 charge cycles but then I forgot to unplug it next time and it was maybe couple hours after it reached 100% and capacity dropped instantly to around 8600mAh and from that on drops were sharp, 22 cycles was already down to 8300. Now it has 82 cycles and only 8051mAh and it show in running time also. iMazing says it is about 94% but obviously counting from 8557, while in reality it is only about 91% counting from supposed 8827mAh. Hard to see that batteries like this will last anything near 500 or was it even 1000 cycles iPad batteries supposed to be rated for? And as a note before anyone even suggest I'm running deep cycles or such causing it to die so soon- I'm not, I never let it run very low and charge it usually when it reach about 40% or so.

I'm also confused about design capacity vs what seen in reviews. Obviously they put different quality batteries in some of these. All iPad's I could get in my hands had 8557 and some were weak right out of the box.
I will be paying definite attention to this. Thanks for the information!
 

Motionblurrr

macrumors 6502
Jul 1, 2008
451
76
Ha!

Same thing happened with my 8+'s new battery. Except it dropped to 99% in the first 2 weeks! It's still at 99% but Coconut battery fluctuates in the same manner as you're saying for me too.

I upgraded from a 6 Plus to an 8 Plus and my 6 Plus still read 85% at about 1,200 cycles. I wasn't monitoring anything during that time, I just charged and used it as a pleased.

I might keep this phone for a while, so I'm getting into the battery charging thing and I've heard that 65-75% is the sweet spot to keep it at throughout the day if you can.

Who knows tbh.
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
I will be paying definite attention to this. Thanks for the information!
By the way, I had iPad Air for about 3,5 years and many hundred charge cycles but it was still around 8500mAh, which I consider normal if it is supposed to last 1000 charge cycles. So my iPad 2018 is already near 8000mAh vs 3,5 year old Air 8500mAh. Both are supposed to have the same battery. Both units have the same use and my charging habits have not changed (actually 2018 came with 10W charger vs 12W with Air, so it should be even better due to that thou I have noticed difference in charging time between the two).
 
  • Like
Reactions: BigMcGuire

GGJstudios

macrumors Westmere
May 16, 2008
44,365
703
By the way, I had iPad Air for about 3,5 years and many hundred charge cycles but it was still around 8500mAh, which I consider normal if it is supposed to last 1000 charge cycles. So my iPad 2018 is already near 8000mAh vs 3,5 year old Air 8500mAh. Both are supposed to have the same battery.
They do not have the same battery.
 

BigMcGuire

Contributor
Jan 10, 2012
4,681
5,724
California
By the way, I had iPad Air for about 3,5 years and many hundred charge cycles but it was still around 8500mAh, which I consider normal if it is supposed to last 1000 charge cycles. So my iPad 2018 is already near 8000mAh vs 3,5 year old Air 8500mAh. Both are supposed to have the same battery. Both units have the same use and my charging habits have not changed (actually 2018 came with 10W charger vs 12W with Air, so it should be even better due to that thou I have noticed difference in charging time between the two).
The iFixit Teardown shows 32.9 Whr and 3.73 V = 8827 mAh. Apple's own specifications show 32.4 Whr - https://www.apple.com/ipad-9.7/specs/

So 32.4 Whr and 3.73? V = 8686 ? lol. Definitely a little bit of a difference.

I'm not going to be taking apart my iPad 2018 :p but I'm very happy with its battery life, for now.
[doublepost=1551719519][/doublepost]
They do not have the same battery.
Definitely appears to be the case. iFixit seems to think it is the 8827 in the iPad 5. Apple's own website says it's not the 32.9 Whr but instead a 32.4 Whr.

Interesting times!
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
They do not have the same battery.
And you know that for sure how?
From what I understood from iFixit teardowns iPad Air, 2017 and 2018 all had the same model and capacity battery inside. See their photos yourself.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,365
703
And you know that for sure how?
From what I understood from iFixit teardowns iPad Air, 2017 and 2018 all had the same model and capacity battery inside. See their photos yourself.
Based on the information you provided (3.5 years ago vs 2018), they don't appear to be the same battery. If you want to provide model numbers of the iPads you're referring to, it would help.
 

BLBL

macrumors 6502a
Apr 11, 2018
758
104
Based on the information you provided (3.5 years ago vs 2018), they don't appear to be the same battery.
I have no idea what you mean by that but it sounds like you understood wrong the capacity figures I posted - they are not design capacities but actual capacity. So in 3,5 year old iPad that has been charged several hundred times still had more capacity left than rather new 2018 version (which has lost already about 800mAh or 9% from the design capacity)!!

If you look at iFixit teardown for Air, 2017 and 2018 models you see what battery was inside (the same in all three).