iPhone 13 Pro Max Why is my iPhone battery health dropping so fast

[Ucshade]

I got this phone on the used market and it was at 87% health which I confirmed with other tools I use to check the accurate battery health.
Now just within a week and some days my battery health first drop to 86, about 3 days later drop to 85, i got up this morning to discover it’s now in 84, I’ve been so worried about this and I always make sure to monitor how I charge it too,,,, I believe the cycle count from the last time I check should be arround 600 or less, because when I first got it, it was 507 or so cycle count, am
On iOS 18.1.1

Normally I don’t like update to the latest iOS but I can’t help cos I got this phone used coming with this iOS version. Could this be a huge problem to me?

 

[Andeddu]

It’s fine, I have noticed that iOS doesn’t give you a true depiction of your battery health. My iPhone 6S was stuck on 84% forever, literally months, and then when it eventually dipped to 83%, it only stayed there for a week before dropping to 82%.

The issue you’re having is not a “huge problem” as everything can be mitigated with a battery service from Apple. You’ll need to replace the battery soon anyway as you purchased it when it was already well worn.

 

[Ucshade]

It’s fine, I have noticed that iOS doesn’t give you a true depiction of your battery health. My iPhone 6S was stuck on 84% forever, literally months, and then when it eventually dipped to 83%, it only stayed there for a week before dropping to 82%.

The issue you’re having is not a “huge problem” as everything can be mitigated with a battery service from Apple. You’ll need to replace the battery soon anyway as you purchased it when it was already well worn.

Unfortunately there’s no apple certified repair store in my country, just third party here and there

 

[now i see it]

iOS Battery Health reporting isn't accurate

 

[menist]

Check with Coconutbattery, its more accurate.

 

[MarkX]

Just charge and use your phone as normal and stop being obsessed with a number!

If and when you need to replace the battery do so!

 

[JPack]

600 cycles is already due for replacement. Doesn’t really matter what the capacity number is as is often inaccurate.

 

[Ucshade]

600 cycles is already due for replacement. Doesn’t really matter what the capacity number is as is often inaccurate.

I know just that in my country here there’s no apple authorized service center and I hate going to third party, for this reasons I monitor my phone to make sure it serves me till am ready to sell off and upgrade,,, I’ve used an xs max which was 1600 cycle count so

 

[Ucshade]

600 cycles is already due for replacement. Doesn’t really matter what the capacity number is as is often inaccurate.

I’ve used an xs max which cycle count was as high as 1600

 

[Ucshade]

Check with Coconutbattery, it’s more accurate.

Can coconut battery work on windows

 

[sw1tcher]

First, upgrade from iOS 18.1.1 to 18.3.1. There could be bugs in 18.1.1 causing battery issues. That might help a bit. But as JPack said, if you're at around 600 cycle counts already, that battery is worn and in need of replacing unless you're ok with short battery life.

iPhone battery and performance - Apple Support (HK)

Understand iPhone performance and its relation to your battery.

support.apple.com

Batteries of iPhone 14 models and earlier are designed to retain 80 percent of their original capacity at 500 complete charge cycles under ideal conditions.


Since it's a used and 3 year old iPhone, it's possible the previous owner replaced the original battery with a cheap generic battery and that's why the battery percentage has dropped so quickly from 87% to 84%

No, coconut battery is only for Mac

 

[Shirasaki]

Can coconut battery work on windows

Unfortunately no it doesn’t. It’s a Mac only app afaik.

 

[Ucshade]

First, upgrade from iOS 18.1.1 to 18.3.1. There could be bugs in 18.1.1 causing battery issues. That might help a bit. But as JPack said, if you're at around 600 cycle counts already, that battery is worn and in need of replacing unless you're ok with short battery life.

iPhone battery and performance - Apple Support (HK)

Understand iPhone performance and its relation to your battery.

support.apple.com

Batteries of iPhone 14 models and earlier are designed to retain 80 percent of their original capacity at 500 complete charge cycles under ideal conditions.


Since it's a used and 3 year old iPhone, it's possible the previous owner replaced the original battery with a cheap generic battery and that's why the battery percentage has dropped so quickly from 87% to 84%

No, coconut battery is only for Mac

I really don’t think so, 3utools shows same battery type and serial number, meanwhile my iPhone is not indicating unknown battery under the settings> repairs

 

[Parowdy]

I’ve recently noticed something similar on my 15 Pro, battery health went from 100-97% in 25 cycles. I’d say I’m not mad that it took over 200 cycles to drop a single percent, but then it took 25 to drop 3%.

This just reenforces my believe that these „estimates“ are more than flawed and I don’t know how legal it is for Apple to literally refuse to service devices with more than 79% battery health left.

However, let me ask you this, how much are 100 bucks worth to you? Would you rather spent $100 at some point in the future OR bother about your iPhone‘s consumable battery every. single. day.?
I took option two for years and am so, SO much more happy since I decided not to care that much anymore.
It either WILL have to be replaced at some point or you will upgrade to a newer device. When it comes to that you WILL have to think about what you’re going to do, until then, you DON‘T have to bother yourself with it.

 

[Reverend Benny]

Since you are already on iOS 18, update to the latest version. There are all sorts of bugfixes and most likely for the BMS as well.

 

[TechnoMonk]

Battery deterioration is not linear. It can drastically go down depending on the age. I have had batteries go down from 86% to 81% in few weeks. But then the battery was 3.5 years old. No big deal, replace the battery when it’s time. Obsessively worrying about battery is unhealthy.

 

[Ramandeepsingh]

Heat and bad charger, cable might be causing this sudden drop

 

[JeffAdams]

I got this phone on the used market and it was at 87% health which I confirmed with other tools I use to check the accurate battery health.
Now just within a week and some days my battery health first drop to 86, about 3 days later drop to 85, i got up this morning to discover it’s now in 84, I’ve been so worried about this and I always make sure to monitor how I charge it too,,,, I believe the cycle count from the last time I check should be arround 600 or less, because when I first got it, it was 507 or so cycle count, am
On iOS 18.1.1

Normally I don’t like update to the latest iOS but I can’t help cos I got this phone used coming with this iOS version. Could this be a huge problem to me?

iOS Battery Health reporting isn't always accurate. It shows the battery's capacity compared to when it was new but doesn't reflect real-world performance or subtle degradation.

 

[roguester]

iPhones are weird. Mine was at 100% for close to a year then the last month it dropped 10% within a month.

 

[Ucshade]

Am so surprised my battery health dipped from 87-82 currently in just roughly a month, although am a heavy user and use only wired charging, according to 3utools my battery is already in service showing 79% health with 565 charge cycles but phone is reporting 82,,, how can I found out the truth about my battery or is it something I should be worried about. Btw my apple analytics report is not showing log aggregated file I don’t know why cos it has been in my previous iPhones. Lastly for no reason the “parts and service” history on my iPhone suddenly disappeared. Although I’ve not repaired the phone but after updating to iOS 18.1.1 I noticed the parts and service on the about section, now it’s no longer there

 

[reppans]

Nm