Become a MacRumors Supporter for $25/year with no ads, private forums, and more!

zorinlynx

macrumors 604
Original poster
May 31, 2007
7,200
13,766
Florida, USA
My mother has complained that her iPhone 6's battery life is not what it used to be.

I checked Battery Health and it said 95%;. It also says performance management has been enabled; that's not too surprising as it's a five year old battery. She hasn't had any performance complaints as she's far from being a power user.

Plugged her phone into my Mac and ran CoconutBattery and it said the full charge capacity was only 62.1% of design capacity... even though Battery Health in iOS itself says 95%! I'm more inclined to believe CoconutBattery as there has been a noticeable decline in battery capacity... Why is the Battery Health indicator in iOS lying?
 

now i see it

macrumors G3
Jan 2, 2002
9,264
18,372
In my experience, coconutBattery is totally unreliable. One day (or even morning) coconutBattery will say my battery health is at sixty something, then later in the day it'll say low nineties. On my phone it's totally worthless. My phone is 4 years old with 1026 load cycles on it and coconutBattery today says it's battery health is at 98.5%. Yeah right.
The "battery health" percentage it gives me typically runs anywhere between 83% to 98%. Useless.
 
  • Like
Reactions: SackJabbit

Nerdyaf

macrumors member
Mar 18, 2019
72
11
1) there could be other reasons for a shorter battery life despite its health at 95%. e.g. some new (or even old ones) apps are using more power or your mum's using habits has changed, like she is spending more time on her phone or made the screen brighter.

2) i have some doubts about the 95% battery health because it's a 5 year old battery

3) i also do not fully trust coconutbattery because i suspect apple may not allow the app to access certain system information and hence the info is just an estimation

4) the battery health info is not key; no point that the battery health is at 100% but still died on your mum. Rather, is the degraded battery still good enough for your mum, or what can you do to help with the problem? like charging mid day, changing her habits, switching off background refresh, or low power mode, before deciding to get a new battery.
 

BigMcGuire

macrumors G3
Jan 10, 2012
8,243
10,033
the Alpha Quadrant
Apologies for the length of this post.

I don't think either are lying. As a self prescribed battery hobbyist, I must admit I'm not entirely sure what is going on. I have watched all of my devices with coconutBattery since the 6+, to the 6s+, to the 8+, and now Xs MAX. I take weekly readings and focus on the battery capacity vs design capacity. I usually keep my phones for 1.5-2 years. My wife gets the same phone I do so I have 2 phones to "observe" and compare against with very different usage. I'm a light user and my wife is a heavy user of her phone.

After 2 years and 230 - 300 cycles my phones have had little to no battery degradation in terms of overall capacity. The worst was my 6+ that went from 108% from design capacity to 98% after almost 2 years. Most of my other phones strayed a percentage or two (6+ and 8+) - this includes iPads.

My wife's 6s+ was the only anomaly in our lineup of phones from the 6+ to the Xs MAX. She had a bad battery from the factory. Less than 6 months into ownership, her phone would randomly shut off and last easily half as long as my identical phone. coconutBattery showed her battery capacity randomly fluctuating between 40%, 60%, and 90%. Of course, when we took it into Apple, they showed "green" and healthy. We showed them how it shut off below 70% with any load. They shrugged their shoulders and had to be forced to let me pay them for a new battery out of pocket. In so doing, they destroyed my wife's 6s+ and we got a new 6s+. Later on, during the battery fiasco that spawned the Battery Health reader in iOS, Apple refunded us $50 without us having to do anything.

Batteries are a chemistry. Getting an accurate reading on them is difficult, especially over time. Battery capacity can vary depending on when you do the reading. For consistency I only read at full charge. I've seen a 3-6% capacity difference when reading below a full charge, even more at a 20-40% charge. On an older battery, this capacity difference will widen significantly, especially if a reading is taken further away from a full charge.

Apple's health meter is definitely pre-programmed to take a different approach to reading battery capacity. The fact that your phone's performance management was enabled means the battery dipped below acceptable voltage. This is the same thing my wife's 6s+ did (voltage drop). I believe Apple got a batch of bad batteries that had difficulty maintaining their voltage as the phones aged hence their willingness to do cheap battery replacements to help satisfy these unhappy customers.

I do not see a problem with a phone having a 95% capacity after 1000 cycles. My boss' 4s had 86% capacity after many years and 1200?+ cycles. Battery wear is not linear like a glass of water. It is not a guaranteed thing that after 500 cycles your phone's battery will be 80% capacity - Apple just warranties that it will be >=80%.

I don't think coconutBattery is inaccurate. I do think reading a chemical reaction like a Lithium Polymer battery is "difficult" and not 100% accurate after time. I think that these batteries dip in voltage and capacity from 20-60% and tend to stabilize more after 80% charge when doing capacity readings.

On the topic of Apple's Battery Health meter - I think they only read at near full charge and probably are programmed to read high values because if it showed 80% or lower it would qualify the user for a replacement on a less than year old (or two for AppleCare+) phone.

This is only my opinion - I'm a battery hobbyist only. My only claim to fame is that I've read https://www.amazon.com/Batteries-Portable-World-Rechargeable-Non-Engineers/dp/0968211844/ several times. The author of this book is the author of https://batteryuniversity.com and I've had the privilege of conversing with him via a short email.
[doublepost=1553223411][/doublepost]I wish companies would give us more access to battery information. I imagine companies prefer to keep this information "hidden" as it would show non-favorable results.

My Dell XPS 15, purchased last year (2018) during Black Friday, according to Window's own battery report, has lost 10,000 mAh since I bought it. My Samsung Note 3, rooted, showed it losing 50% of its design capacity in less than 7 months (thankfully batteries were easy to replace and cheap). My Dell D830's battery couldn't hold a charge after a year and shut the laptop off instantly when unplugged.

One reason why I prefer Apple products is that they, in general, have had far superior battery life and longevity over other products I've had in the past.
 
Last edited:

Minorite

macrumors 6502a
May 8, 2018
521
122
Poland
CoconutBattery should be more accurate. Double-check with iMazing and compare effective max charge in mAh, should be the most accurate answer.
 
  • Like
Reactions: BigMcGuire

perezr10

macrumors 68000
Jan 12, 2014
1,667
987
Monroe, Louisiana
My sons iPhone 6 needed a battery replacement and the Settings said 84%. Coconut battery said 65%. Since the battery life was forcing shutdowns I believe Settings is way too optimistic.
 
  • Like
Reactions: BigMcGuire

mikzn

macrumors 68040
Sep 2, 2013
3,005
2,284
North Vancouver
Personally I don't like the limited and dumbed down info that apple iOS provides on battery health and status

I do like and value the info coconut battery provides and also the fact that you can record the history of each of the iOS devices and my MBP's

It's good to know the Cycle Count, plus the "Full Charge Capacity charge vs Design Capacity" - my experience has been after 800 cycles the Charge Capacity charge starts to become significantly less than the Design Capacity and loses the ability to hold a charge for very long.
 
  • Like
Reactions: BigMcGuire

now i see it

macrumors G3
Jan 2, 2002
9,264
18,372
what's kinda revealing is that there is no standard against which coconutBattery can be calibrated against. There never has been a way to know what it's saying is accurate or not. It was the old standard based on..... itself.

There's zero data or evidence or anything that the numbers coconutBattery show us are anything but guesses. Yet everyone says "coconutBattery is accurate".

Based on what evidence?

None.
 
  • Like
Reactions: Shark5150

subjonas

macrumors 68040
Feb 10, 2014
3,971
3,940
what's kinda revealing is that there is no standard against which coconutBattery can be calibrated against. There never has been a way to know what it's saying is accurate or not. It was the old standard based on..... itself.

There's zero data or evidence or anything that the numbers coconutBattery show us are anything but guesses. Yet everyone says "coconutBattery is accurate".

Based on what evidence?

None.
Good point. Are there multiple battery applications? Would a comparison test tell us anything? I suppose even if two applications consistently end up with the same results, it could just mean they’re both getting their information using the same incorrect method. I guess it’s impossible for us to know for sure.
 
  • Like
Reactions: BigMcGuire

AppleHaterLover

macrumors 68020
Jun 15, 2018
2,047
2,049
If it’s lasting less than it used to, have it replaced. End of.

That’s why I’m against this battery readout. What are you supposed to do with this information when what really matters is how long the damn battery is lasting?
 
  • Like
Reactions: perezr10

dazz87

macrumors 68000
Sep 24, 2007
1,581
1,622
Same here....iOS was running 87% for my mom's iphone 6....Coconut was showing 50%...Phone was crawling and battery life was just trash.
 

mikzn

macrumors 68040
Sep 2, 2013
3,005
2,284
North Vancouver
There's zero data or evidence or anything that the numbers coconutBattery show us are anything but guesses. Yet everyone says "coconutBattery is accurate".

Based on what evidence?

None.

Well for the most part Coconut Battery is just pulling the same info that is on the apple hardware but hidden by apple - much of this info used to be easier to find but has been incrementally dumbed down from the mac energy saver or on iOS replaced by app usage info (personally I don't want to know that Phone calls, Netflix or Safari are consuming the battery - it's a blinding glimpse at the obvious)

You can still find this same exact info on a mac in the "About this Mac" menu < Hardware < Power < Battery information

I have always found Coconut Battery to report the exact same info for Battery%, Cycle count, Full Charge Capacity, Current Charge for both the macOS and iOS - just easier to access and having the history of that same info is a very nice add on - IMHO

so unless the apple info itself is inaccurate . . . ?
 

whrage

macrumors newbie
Nov 23, 2016
7
3
Hungary
I think Coconutbattery is more accurate. My 6s has a 1 year old battery and it says 92%. Coconut says it's 77%. I need to charge the phone 3x a day, so I guess it can't be on 92%... 1 year ago it was much better when I had the new battery.
 

Racineur

macrumors 6502
Jun 11, 2013
458
132
Montréal, Québec
Great thread. I have the same problem with my 6s. February 2018, two years after I bought it, battery was 81%. Phone was on iOS 11. Could use the Apple replacement program. Stayed at 100% very long but in late 2019, down to 98% on iOS 14.2 and now in December 2020, still at 98%? but the phone has experienced perhaps 3 shutdowns in the 6 past months. Of course the message appeared "This iPhone has unexpectedly...". Disabled Coconut reads the battery at 84.5% and 138 cycle count. Which to me is more in tune with the shutdowns. How could my 6s shutdown with a battery at 98%. Called Apple service. They took control of my phone and, guess what, they suggested I upgrade to iOS 14, which I was about to do anyway. They took control of the phone mumbling something that sounded like "Your battery is "swuisokforyouthounow". The message "This iPhone has unexpectedly..." is still there. Problem: I like my 6s -no games, no Tube-Face-Gram-Tok and al. Uses it in my car, Maps, Mail, Safari, Notes, Reminders, News. Few third party apps if not the one of my Service provider, HufPOst, CNN and the kinds. So it serves me well for what I do but if the battery has gone down so much, I have to pay 69$ Apple asks (Yep, I'm in Canada) for a new battery, is it worth? And How can I fu??&*king now when to change the battery. Is it coconut that has the good reading or OS 14. Could there be something wrong with the battery Apple installed in February 2018? These little things make you think if it's not time to get yourself a new phone. What you think please?
 

gtg465x

macrumors 6502a
Sep 12, 2016
641
716
I think Apple’s battery health lies. My 3 year old iPhone X said 82%, but I would say battery life was less than half what it was when new. I used to be able to make it a whole day and end with 10% remaining, but was to the point that I would have to recharge multiple times per day, and my usage hasn’t changed much over the past few years. Unfortunately, I didn’t think to test it with my USB meters before I traded it in. My USB meters can measure how much power goes in to something when charging, so if the phone read 100% charged before 82% of the battery’s rated mAh had been sent over USB, it would have proved Apple is lying. Too bad I didn’t test it.
 

BrettApple

macrumors 65816
Apr 3, 2010
1,126
447
Heart of the midwest
iOS was telling us this was still at like 80% or something, I didn't buy it one bit.

1607181509142.png


Replaced it over thanksgiving break myself (it's my out of state in-law's phone)

1607181609323.png


And I hear it is MUCH better now :)

I don't trust the one in iOS for much at this point. Seen it lie too many times. Replaced an 800 cycle battery and about to do another with 1,800 cycles sooner rather than later. And that one was already replaced in 2014.

1607181799371.png


It's likely a good indicator to show if it's getting throttled or not due to low voltage shutdown but not so much it's total capacity or cycle count health. I'd LOVE iOS to tell us the cycle count at least, if not the capacity. My Samsung could do that with a 3rd party app, why not an iPhone?
 

yticolev

macrumors 6502
Sep 27, 2015
297
274
I think it is rather clear that a failing battery does not yield accurate numbers or show any consistency. If this happens, and needs more recharging than usual, the battery needs replacement. The analysis done at the Apple Store is no better, and usually requires several trips to prove that you really need a battery replacement.

My last car and driving habits (actually lack of regular driving) was super tough on battery life. Had to replace every two years. I'd jump a failing battery regularly, and the electrical test that mechanics do usually showed good battery health the first couple times. Finally, they replace the battery (I always had some proration left on my warranty but still out of pocket), and I'd be good for a couple more years. Owned that car 20 years, probably replace the battery 8 times.

Bottom line, when a battery is failing, the chemistry involved leads to erratic reports.

BTW, all Coconut Battery does is automate an ordinary Terminal response to a command line inquiry about battery health. Several years ago, I confirmed that the Terminal provided numbers were identical to CB. Where things deviate is current battery charge as per settings or menu bar, and that Terminal number or CB number. The former is graded on a curve, and the CB number is the actual charge.
 
  • Like
Reactions: BigMcGuire
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.