iPhone 8/Plus How will this battery perform at 80% battery health?

[AMSOS]

This thread describe the exact situation I have with my XS Max. The battery health was at 100% for a year and an half, but 1 month ago it goes down directly at 96% and now after I updated it to iOS 13,6 it lost another 1% and now its at 95% like you.

I'm not worrying about it too much though. I just put my phone on the wireless charger every time I go to bed and thats it. If it goes down to 80%, I'll just pay for a battery replacement. It'll still be a better deal than buying a new phone. I plan to keep my phone for at least another 2 years.

Interesting. Can you tell us how you charge the phone? Do you take it down to near 0% or do you use top-up charging?
[automerge]1594936480[/automerge]

Do not mind Apple’s own battery stats and just swap your battery when it becomes a nuisance. Your described charging practices sound good, so you should expect your battery to last you at least two full years.

You mean a total of nearly 3 and half years? That'll be sufficient for my purposes. I'll get a new iPhone after 3 years.
The question is how much of a drop in battery backup should I expect?

 

[SoYoung]

Interesting. Can you tell us how you charge the phone? Do you take it down to near 0% or do you use top-up charging?
[automerge]1594936480[/automerge]

You mean a total of nearly 3 and half years? That'll be sufficient for my purposes. I'll get a new iPhone after 3 years.
The question is how much of a drop in battery backup should I expect?

I think it happens only one or two times when my battery was below 20% before recharging. usually, I put my phone on the wireless charger every night no matter how I used the phone during the day. Usually the battery was at 60-70% when I put it on the charger. I just like to have a full charge when I wake up in case I’ll need it during the day.

I think these days you don’t have to care much with the battery. I think the most important thing is trying to not expose your phone in very hot or cold place, but other than that, just recharge when you need it/want it and it should be fine.

 

[now i see it]

Here's what coconutBattery says about my iPhone battery. Whether it's anywhere near accurate is anyone's guess.

I've been using this iPhone all day long, every day since I got it (1551 days ago). It rarely sits idle. Using the battery obviously doesn't wear it out (as my long term test reveals). It's charging it to high voltages (above 80% SOC) and discharging it too deeply (below 20% SOC) that seems to shorten the life of phone batteries.

 

[AMSOS]

Here's what coconutBattery says about my iPhone battery. Whether it's anywhere near accurate is anyone's guess.

I've been using this iPhone all day long, every day since I got it (1551 days ago). It rarely sits idle. Using the battery obviously doesn't wear it out (as my long term test reveals). It's charging it to high voltages (above 80% SOC) and discharging it too deeply (below 20% SOC) that seems to shorten the life of phone batteries.

This is amazing! I'd love to be in your shoes
What is the maximum you charge the phone to? I see from the screenshots that it is 89%. I would imagine a much shorter battery life span if you regularly charged to 90% or more.
Can you share your use and charging habits?
Is the phone on flight mode overnight?
Is it mostly used indoors in moderate temperatures?
Do you ever let it discharge to 0-10%?
What about video calls/games? That's demanding stuff that really taxes the battery.
Finally, after how many years did you start noticing a drop in battery backup? Enough for you to have to increase the charging frequency.
Thanks for sharing!

 

[aakshey]

It is 100% luck. My phone is like 8 months old. iPhone 11 Pro. 190 cycles. Varies between 101-104% on average.

I fast charge overnight daily. Sometimes more than once a day. It goes down to 15-30% daily.

 

[BigMcGuire]

Don't worry about it and stop fretting over the battery health estimate app. It only warrants a peek when the battery doesn't last anywhere near what it did when new.
The capacity of a brand new battery isn't really a realistic bar to measure up to. They don't keep that capacity for long.

My iPhone 6 Plus original battery is six years old with 1550 load cycles on it and I use the phone all day long every day. (and charge it partially during the day). Battery health (according to CoconutBattery) is still over 90%.

If you never charge the battery to 100% and keep it above 20%, the battery will outlast the phone.

You are an inspiration. I want to do this. I too have similar questions as AMSOS. When do you pull it off the charger? Ever use wireless?

Amazing!

 

[now i see it]

The iPhone I had before this one was a used iPhone 5 that was given to me. It was used hard by the previous owner but I don't know what the battery condition was when I got it. Back then I was clueless about how to take care of the battery so I left it plugged in 24/7 for months as I was stuck at home with an injury.

After a couple months of always being plugged in even while I used it during the day, the battery began to swell and push the screen off the chassis.
I got a mobile cell phone repair shop to come to my place to swap the battery and I told him how I was using it (always plugged in) and he said don't do that.

So after getting spanked by a swollen battery, I vowed to find out the best way to take care of them and studied up at

Battery University Homepage

Battery University™ is a free educational website offering hands-on battery information.

batteryuniversity.com

That website currently is the best place to learn about lithium ion batteries.

So when I got my brand new shiny iPhone 6 Plus, (4 years ago) I was determined to take care of that battery the best way I could, - following the care tips I learned at Battery University.

So I've kept the charge on this battery (for the most part) between 45% and 80% with maybe two dozen charges to 100% over the years to recalibrate the charge level indicator a couple times and because a few times I left it unattended plugged in. I found that if I never charged it to 100% (for like 8 months) the charge indicator would become erratic and inaccurate.

For the first three years I always turned off the phone completely when I went to sleep and not plugged in. If the battery was at 50% (or 40%) when I went to sleep, I'd leave it partially discharged like that when I turned it off and charge it the next morning (but never to 100%).

What I learned about lithium ion batteries (from battery university) is that they are happiest resting at their nominal voltage, which is about 40% SOC. As the voltage and charge level increases beyond that, so does the stress on the battery. The higher the charge level, the more stressful it is on the battery.

I think the deepest this battery has ever been discharged was to maybe 5% once or twice (in 4 years.

This last year I've been leaving the phone on (but unplugged) when I sleep because when I wake up in the middle of the night I like to check the time. Knowing if it's 1:30AM or 4AM makes a big difference. I don't have a watch or another clock I can see at night. I leave it in Airplane Mode (WIFI & Bluetooth off) and usually put it in Low Power Mode if I remember to eeek a little more power savings out of it.

I live in the desert. Summertime temps are always hot as hell and even indoors it gets to 100° or hotter during late afternoon... for four months of the year. When the air temp gets to about 96°F, I strap a small frozen blue ice block stuffed in a sock to the back of the iPhone with rubber bands (big bezels top & bottom are perfect for this). The cold block brings the battery temperature down from a hand scorching 105°F to a comfortable 75° to 85° depending on what I'm doing.
Obviously with a ice pack strapped to it, it doesn't fit in any pocket.

I haven't really noticed any obvious degradation of the battery since I got it new over 4 years ago. CoconutBattery says the capacity is still over 90% and that feels about right. I can't tell.
Since I got it, I almost never charged it to 100% and used it down to 10% in one go, so I don't really have a reference to benchmark it against (since I usually plug it in when I see the forty something indicator on the charge status icon.

All of this attention paid to the battery is actually kind of ridiculous. A new genuine Apple battery only costs $49. Ha!
But I've been pampering device batteries for so long now, it's become an ingrained habit... and kinda fun to see how far it'll go...

I'd like to be using an 8 Plus now instead of my trusty 6 Plus, but since I've also got a 7 and 8 I almost never use, (because of their smaller screens) I can't justify buying another phone just for the bigger nicer screen.
So I'll use this phone until it dies.

 

[AMSOS]

All of this attention paid to the battery is actually kind of ridiculous. A new genuine Apple battery only costs $49. Ha!
But I've been pampering device batteries for so long now, it's become an ingrained habit... and kinda fun to see how far it'll go...

Quite a comprehensive reply-thanks!
Hats off to you for working with the ice-pack. I wouldn't be able to go that far Haha. So far, I am following in your footsteps in many ways and hopefully the 8 battery will also last.
And for those who always remind others to not think too much about the battery, your response above says it all