Battery Health

NJHitmen

macrumors 6502
Oct 8, 2010
331
287
No, that's not good at all. To be clear: the health percentage isn't a comprehensive assessment of the battery's condition - it's just one set of measurements. In other words, if two phones report a battery health of 85%, one may be usable while the other isn't. That said, most phones reporting 85% battery health will demonstrate significantly compromised performance.
 
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FeliApple

macrumors 65816
Apr 8, 2015
1,347
493
More than battery health, I'd look into battery life. My iPhone 5c has 83% health and its battery life is awful, but it was updated to iOS 9.
On the other hand, my iPhone 6s is on iOS 9 with 91% health; I would probably say I should see some kind of reduced battery life. It lasts exactly the same it did when new.
 

now i see it

macrumors 603
Jan 2, 2002
5,355
10,815
If the battery isn't lasting long enough for you between charges, then it isn't "good enough". If it lasts long enough to not be a hassle to charge it, then it's fine - for you.

Someone could have an old iPhone battery with only 60% capacity remaining, but if it lasts long enough for their use before they need to recharge it, then the battery is fine enough- for them.

Even a brand new battery doesn't last very long if you use the phone non-stop constantly.
 

Knight3

Suspended
Oct 19, 2018
280
271
On the other hand, my iPhone 6s is on iOS 9 with 91% health; I would probably say I should see some kind of reduced battery life. It lasts exactly the same it did when new.
I’m trying to make sense of this.
How could a phone or any device for that matter perform perfectly regardless of battery deterioration? Provided every other variable has stayed the same.

Genuinely confused and curious as to what might’ve changed.
 

joeblow7777

macrumors 603
Sep 7, 2010
6,197
7,249
It's better than 84% but not as good as 86%.

Seriously, only you can decide if your battery is performing well enough for you or not.
 
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mrex

macrumors 68040
Jul 16, 2014
3,321
1,394
europe
I think 85% is fine - depending on the cycles/ battery life and the whole condition of course... mine was 82% before i got it replaced, but the reason was not that but my phone sometimes went off when there was still 40% left. the phone wasnt reliable. The battery was original (6S+, 3yo battery) and maybe a bit faulty too... cost me 39euros and now the phone works fine again when the charge goes below 40%...
 

xxray

macrumors 65816
Jul 27, 2013
1,213
1,639
It’s not good, but I’d probably try to make it last till it gets under 80%.
 

FeliApple

macrumors 65816
Apr 8, 2015
1,347
493
I’m trying to make sense of this.
How could a phone or any device for that matter perform perfectly regardless of battery deterioration? Provided every other variable has stayed the same.

Genuinely confused and curious as to what might’ve changed.
Honestly, I have no idea why. I have seen a slight degradation on my iPad Pro 9.7 with 93% health running iOS 9 (slight meaning from an average of 14 hours to barely scraping 13). I would have expected similar degradation in battery life on my iPhone but it hasn't happened.
Other variables remain unchanged (every single setting has been steady since I first set it up; app usage has more or less remained constant). Why haven't I seen any kind of degradation is a mystery.
 

srsub3

macrumors 6502
Mar 10, 2013
417
274
NYC
I guess they introduced another killer switch, more subtle than the other. Before last two updates, my battery health was 93%. It depleted to 88 in less than a month. Phone is slower... The first thing I noticed is that you should press lateral button for a long time to boot the phone, let's say 5-6 seconds. I can clearly remember that it took 1 fast 1 second long push before. iPhone 8, one year old.... by chance we are in the same period the battery gate came out last year....
 

C DM

macrumors Sandy Bridge
Oct 17, 2011
48,916
17,557
I guess they introduced another killer switch, more subtle than the other. Before last two updates, my battery health was 93%. It depleted to 88 in less than a month. Phone is slower... The first thing I noticed is that you should press lateral button for a long time to boot the phone, let's say 5-6 seconds. I can clearly remember that it took 1 fast 1 second long push before. iPhone 8, one year old.... by chance we are in the same period the battery gate came out last year....
The side button should take a longer to boot up the phone to avoid accidental boot ups. Doesn't have to do anything with the battery or some "killer switch".
 

srsub3

macrumors 6502
Mar 10, 2013
417
274
NYC
The side button should take a longer to boot up the phone to avoid accidental boot ups. Doesn't have to do anything with the battery or some "killer switch".
And then why it depleted of 5% in a month?
 

brent12

macrumors member
Jun 24, 2013
39
13
I’m trying to make sense of this.
How could a phone or any device for that matter perform perfectly regardless of battery deterioration? Provided every other variable has stayed the same.

Genuinely confused and curious as to what might’ve changed.
When an iPhone is indicating battery at say 83%, it is still (in general) providing the same voltage as a battery at 100% but it will not be able to do so for as long. So your phone should perform about the same unless Apple for instance throttles the hardware so it drains the battery more slowly by running the phones hardware (CPU, etc.) more slowly.
 

JPack

macrumors 603
Mar 27, 2017
5,778
8,918
When an iPhone is indicating battery at say 83%, it is still (in general) providing the same voltage as a battery at 100% but it will not be able to do so for as long. So your phone should perform about the same unless Apple for instance throttles the hardware so it drains the battery more slowly by running the phones hardware (CPU, etc.) more slowly.
When battery capacity decreases to 83%, battery impedance increases due to age. Impedance affects the battery's ability to deliver peak power.

Apple didn't throttle phones to increase runtime, they did so to avoid unexpected shutdowns associated with increased battery impedance.

A battery at 83% isn't able to deliver the same peak power as a new battery. That's why Apple limits burst activities like speaker volume, camera flash, and processor frequency during the throttled state.
 
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Knight3

Suspended
Oct 19, 2018
280
271
When an iPhone is indicating battery at say 83%, it is still (in general) providing the same voltage as a battery at 100% but it will not be able to do so for as long. So your phone should perform about the same unless Apple for instance throttles the hardware so it drains the battery more slowly by running the phones hardware (CPU, etc.) more slowly.
I don’t think that’s what it means.
 
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