iPhone 15 Pro Keep iPhone 15 Pro at 80% limit on charger

[James6s]

Recently started using the 80% charge limit on my 15 Pro and I’m wondering would be fine and not detrimental to the battery by keeping it plugged in at 80%, whilst I’m at home for example?

I’m assuming it’s better than it sitting at 100% continuously and why this feature was introduced as it’s not classed as a high state of charge?

I’ll be using this device for at least 2 years so the longer the battery holds up the better 😁

 

[Helmsley]

Keeping iPhone on charge a lot will cause battery wear as it adds to the overall charging cycles.

I think you'll be fine for the two years that you'll have the device, though.

 

[James6s]

Thank you. I thought that leaving it plugged in at 100% for long periods was the worst for battery degradation? Hence the optimised charging & now the 80% limit.

Will it not go through more cycles by letting it drain and then plugging back in, for example 30/40-80% maybe twice a day?

Maybe I shouldn’t try and micro manage the battery and just use it lol

 

[Helmsley]

Thank you. I thought that leaving it plugged in at 100% for long periods was the worst for battery degradation? Hence the optimised charging & now the 80% limit.

Will it not go through more cycles by letting it drain and then plugging back in, for example 30/40-80% maybe twice a day?

Maybe I shouldn’t try and micro manage the battery and just use it lol

Keeping iPhone plugged in means it's constantly topping up the battery, adding to charging cycles.

 

[bigjnyc]

That is the purpose of this feature. Keeping the battery at 100% for an extended period of time is terrible for batteries. keeping it at 80% is much better.

 

[Reverend Benny]

About the battery and performance of iPhone 11 and later - Apple Support (OM)

Learn about the battery and performance of iPhone 11 models and later.

support.apple.com

"Batteries of iPhone 15 models are designed to retain 80 percent of their original capacity at 1000 complete charge cycles under ideal conditions."

 

[James6s]

Come across this from Apple. Sounds like it will only start charging again once the battery drops to 75%, rather than a constant trickle charge keeping it at 80%?

 

[contacos]

My assumption always was that if you keep your phone or MacBook for that matter plugged in at the 80% threshold, it basically operates straight from the power outlets power source, passing through the battery without actually using it. I doubt it constantly charges between 79% and 80% to keep it always at 80%. Sort of like a tv that only works plugged in and has no battery?

I used my old MacBook Pro from 2012 99% plugged in on the desk and it’s battery health is still at 92% according to coconut battery

 

[Reverend Benny]

My assumption always was that if you keep your phone or MacBook for that matter plugged in at the 80% threshold, it basically operates straight from the power outlets power source, passing through the battery without actually using it. I doubt it constantly charges between 79% and 80% to keep it always at 80%. Sort of like a tv that only works plugged in and has no battery?

I used my old MacBook Pro from 2012 99% plugged in on the desk and it’s battery health is still at 92% according to coconut battery

I think BMS constantly improves, both using new HW and via SW updates such as new iOS and MacOS.
iPhone15 seems to have improved BMS that gives more info, added functionality and so on. And looking back we can see that older phones that has received added functionality when it comes to battery management with every iOS update.

 

[rocketbuc]

My assumption always was that if you keep your phone or MacBook for that matter plugged in at the 80% threshold, it basically operates straight from the power outlets power source, passing through the battery without actually using it. I doubt it constantly charges between 79% and 80% to keep it always at 80%. Sort of like a tv that only works plugged in and has no battery?

I used my old MacBook Pro from 2012 99% plugged in on the desk and it’s battery health is still at 92% according to coconut battery

This is how things are working on the Mac. You see this with AlDente when the charging stops, the MacBook runs entirely off the battery without increasing cycle count. On the iPhone, I think this is not possible - the battery is being charged when plugged in but the required power is taken from the battery rather than the charger. Not 100% sure though.

 

[Jackbequickly]

At 80% and on the charger, it should accumulate cycles at the lowest rate.

 

[lonesoul]

For those who are interested. I have mine plugged in all the time as I'm mostly WFH. It's 4 month old at 15 cycles limited to 80% charge. Don't have any issue at all battery still somewhat totally brand new at 103.5% 4579mAh according to coconut battery. Compared to the missus's phone at 103.1% 4561mAh with ~50 cycles. So the difference its somewhat insignificant so just use and charge the phone the way it is and according to your lifestyle. There's no need to overthink about the battery health i'd say.

 

[James6s]

For those who are interested. I have mine plugged in all the time as I'm mostly WFH. It's 4 month old at 15 cycles limited to 80% charge. Don't have any issue at all battery still somewhat totally brand new at 103.5% 4579mAh according to coconut battery. Compared to the missus's phone at 103.1% 4561mAh with ~50 cycles. So the difference its somewhat insignificant so just use and charge the phone the way it is and according to your lifestyle. There's no need to overthink about the battery health i'd say.

Interesting, thanks for that info. What’s the lowest % you let the battery get down to?

 

[lonesoul]

Interesting, thanks for that info. What’s the lowest % you let the battery get down to?

The lowest I've gotten it down to was around 15ish%, majority of the time its around 30-40% before it was back on the charger.

Also FYI what I've also noticed is it does not trickle charge all the time to keep at exactly 80%. Once its there it will stop charging unless it drops to a certain percentage or when you unplug & re-plug the phone for it to restart the charging back to the maximum 80%/mAh. Seems like Apple's battery management is pretty good so definitely no need to worry about it degrading your battery leaving it plugged in all the time.

 

[James6s]

The lowest I've gotten it down to was around 15ish%, majority of the time its around 30-40% before it was back on the charger.

Also FYI what I've also noticed is it does not trickle charge all the time to keep at exactly 80%. Once its there it will stop charging unless it drops to a certain percentage or when you unplug & re-plug the phone for it to restart the charging back to the maximum 80%/mAh. Seems like Apple's battery management is pretty good so definitely no need to worry about it degrading your battery leaving it plugged in all the time.

Brilliant thank you. That’s what I was thinking and what Apple states, once it reaches 80% it will stop charging and resume again when it gets to around 75%. So not on constant trickle charge. They really have improved BMS on the latest iPhones, and they’re rated to retain 80% capacity after 1000 cycles.

 

[MacCheetah3]

Come across this from Apple. Sounds like it will only start charging again once the battery drops to 75%, rather than a constant trickle charge keeping it at 80%?
View attachment 2356196

By the way, this behavior is the same for 100%. That is, when the battery state-of-charge reaches 100%, it will stop charging until the level is at ~95%, resume charging, and continue this cycle until disconnected from an external power source.

Another FYI: This small ‘maintenance’ cycle isn’t displayed to the user — well, mostly. In other words, the charge percentage indicator(s) will remain at 100% when the 95-100% (or 75-80%) cycle is occurring. However, for example, if the device has reached 98% in this cycle, you disconnect from the charger and begin using, you might notice the battery charge percentage display(s) jump from 100% to 97%. You may also see the true charging behavior in apps such as coconutBattery.

Note: The earlier behavior is not the same as observing a battery level jump from, for example, 86% to 81%. In most instances, such a behavior is probably loss of calibration:

Battery Calibration

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

www.ifixit.com

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

BU meta description needed...

batteryuniversity.com

 

[MacCheetah3]

By the way, this behavior is the same for 100%. That is, when the battery state-of-charge reaches 100%, it will stop charging until the level is at ~95%, resume charging, and continue this cycle until disconnected from an external power source.

Another FYI: This small ‘maintenance’ cycle isn’t displayed to the user — well, mostly. In other words, the charge percentage indicator(s) will remain at 100% when the 95-100% (or 75-80%) cycle is occurring. However, for example, if the device has reached 98% in this cycle, you disconnect from the charger and begin using, you might notice the battery charge percentage display(s) jump from 100% to 97%. You may also see the true charging behavior in apps such as coconutBattery.

Note: The earlier behavior is not the same as observing a battery level jump from, for example, 86% to 81%. In most instances, such a behavior is probably loss of calibration:

Battery Calibration

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

www.ifixit.com

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

BU meta description needed...

batteryuniversity.com

Last but not least, I know your original question was answered but I’ll highlight it for confirmation:

That is the purpose of this feature. Keeping the battery at 100% for an extended period of time is terrible for batteries. keeping it at 80% is much better.

Also:

Batteries - Maximizing Performance

Maximize the life and lifespan of the rechargeable lithium-ion batteries in your MacBook, iPod, iPhone, and iPad.

www.apple.com

 

[James6s]

Last but not least, I know your original question was answered but I’ll highlight it for confirmation:

Also:

Batteries - Maximizing Performance

Maximize the life and lifespan of the rechargeable lithium-ion batteries in your MacBook, iPod, iPhone, and iPad.

www.apple.com

Thank you for the info and explanation. iOS carried out a full 100% charge yesterday from 20% for calibration for the first time since starting the 80% charge limit (over a week ago) I will continue this optimisation, usually from 40-50% back up to 80%.