iPhone 7/Plus Battery Health Has Remained at 81% for the Past Year?!?!?!

[HappyDude20]

Okay so I had my battery replaced at the Apple store on my iPhone Plus. From 100% it then went down to 81% in January of 2020. And since then the battery health has remained exactly the same. How odd that it should conveniently stay at just over 80% for over a year.

edit: btw I charge my phone AT LEAST twice a day from one percent to five percent. My phone is used all
Waking hours of the day.

 

[MacCheetah3]

How often do you reboot your iPhone?

I ask because my theory, based on many of the battery health-related comments here, is battery health calibration=updating only happens during reboots, ibcluding iOS updates/upgrades.

 

[HappyDude20]

How often do you reboot your iPhone?

I ask because my theory, based on many of the battery health-related comments here, is battery health calibration=updating only happens during reboots, ibcluding iOS updates/upgrades.

I haven’t missed an update and am usually the first to do so once it becomes available. Macrumors is the first website I check daily so I’m pretty up to date. As for reboots, I’d say maybe once or twice a month. Nevertheless im
Planning on backing my stuff and restoring the iPhone tonight. I’ll report here what it says once I do.

 

[MacCheetah3]

What I mean is that I don’t believe the device updates the health percentage during normal use only during boot. So, if you don’t reboot your iPhone often, I think, the health percentage will rarely change and then perhaps change drastically.

 

[HappyDude20]

What I mean is that I don’t believe the device updates the health percentage during normal use only during boot. So, if you don’t reboot your iPhone often, I think, the health percentage will rarely change and then perhaps change drastically.

I restored my iPhone to factory settings last night and battery health still states 81%.

odd. Hunch is this is purposeful on Apple's part. Cause once it goes under 80 the
Performance is affected.

 

[twinlight]

I have had mine at 77% for a long time. It recommends me to service the battery yet it is at peak performance capability so I don’t care much. Phone is rarely turned off or rebooted. Possible that it has only happened during updates in the last 6 months.

 

[C DM]

I restored my iPhone to factory settings last night and battery health still states 81%.

odd. Hunch is this is purposeful on Apple's part. Cause once it goes under 80 the
Performance is affected.

Performance/battery life can certainly be affected even above 80%.

 

[madrigal77]

The built in battery report isn’t always accurate. If you have a Mac, try running coconut battery.

 

[C DM]

The built in battery report isn’t always accurate. If you have a Mac, try running coconut battery.

It's also all essentially an estimate as well.

 

[JPack]

Once it goes below 90%, it becomes really inaccurate.

 

[now i see it]

My 5 year old iPhone with original battery has never dropped below 93%.
That's how accurate it is (nt)

 

[madrigal77]

It's also all essentially an estimate as well.

Yes, but it's more accurate than the built in one. It also tells you how many charge cycles, which is important to know as well.

 

[MacCheetah3]

Yes, but it's more accurate than the built in one. It also tells you how many charge cycles, which is important to know as well.

No. It isn't. At least part of the problem originates from "design capacity" being just a target, stored in and pulled from a database, not what your device's specific/actual battery absolutely had when it was manufactured. That in itself can derail the calculation by several percent. Then, we also need to consider how accurate the current full charge capacity is. Therefore, as far as (estimated) determinations go -- if you're obsessed with the "health" number -- is to calculate the reported charge cycles to these numbers:

Batteries - Service and Recycling

Learn about battery service and recycling for Apple devices. All rechargeable batteries need to be serviced eventually.

www.apple.com

Otherwise, just use your device, the tools available to optimize efficiency and performance, as well as accept the facts: batteries degrade and power requirements vary widely with usage.

 

[freakomac]

I had this exact same experience on my old 7+, battery rocketed down from 100 to 87 in 7-8 months, then flatlined at 87.
I have restored the phone and checked with coconut battery as well, its been at 87 for almost forever. I used to charge a minimum of twice a day.

 

[gnolivos]

My iPhone 12 Pro battery has been stuck at exactly 81% for over a year. My theory is, Apple is playing games, because their own policy states that at 80% or less, they will replace the battery for free (assuming you have Warranty or AppleCare).

Very suspicious...

 

[MercuryNL]

My 5.5 year old original XS battery is at 73%.

 

[Clamjuice65]

Okay so I had my battery replaced at the Apple store on my iPhone Plus. From 100% it then went down to 81% in January of 2020. And since then the battery health has remained exactly the same. How odd that it should conveniently stay at just over 80% for over a year.

edit: btw I charge my phone AT LEAST twice a day from one percent to five percent. My phone is used all
Waking hours of the day.

It’s gonna stay at 81% until your warranty is out and will be replaced on your dime 🤓. Apple knows what they doing

 

[NT1440]

Good lord people.

Lithium Ion battery degradation is NOT linear. Countless threads are on this forum.

You lose X% up front in its lifespan, then it “settles” for most of its life, then it degrades more rapidly.

This isn’t a conspiracy by Apple, they don’t control *chemistry*.

Anyone who expects X% per month over time simply hasn’t bothered to do a cursory search on the topic.

 

[JBGoode]

I have an X purchased 5 years ago that’s at 96% and has been that way for half the time I’ve owned it. It stayed at 100% for over 2 years.

 

[MiamiBeach]

My 5.5 year old original XS battery is at 73%.

My XS purchased a few months after release is on 73% as well. Still on it’s original battery however has been “stuck” at that percent for over a year!

 

[MacCheetah3]

Additionally, ensure you occasionally calibrate:

With 80% Limit enabled, your iPhone will occasionally charge to 100 percent to maintain accurate battery state-of-charge estimates.

About Optimized Battery Charging on your iPhone - Apple Support

In iOS 13, your iPhone learns from your daily charging habits to improve the lifespan of your battery.

support.apple.com

Battery Calibration - iFixit Support

All newly-installed smart batteries should be calibrated as soon as possible. This helps your system get an accurate reading on the battery’s state of charge. W

help.ifixit.com

BU-603: How to Calibrate a “Smart” Battery

BU meta description needed...

batteryuniversity.com

There are a few poor presumptions and comparisons as well as some less than thorough analysis at points in this article. However, overall, it’s insightful.