M1 Max 16" Battery Discharges to 80% and Charges to 100% Daily While on AC

[AdriftAtlas]

My M1 Max 16" discharges its battery to 80% on a daily basis and charges it up to 100%. I can see it using the "Battery Power Bus" in iStat Menus when it's plugged in and idle. In two months it has already used 24 cycles even though it's been plugged in except for a handful of hours. I move it from room to room so it briefly loses AC a handful of times a day.

I have no problem with it staying at 80%. In fact, if I could force it to stop charging at 80% that'd be great. What I do have a problem with is needlessly consuming battery cycles.

Is this a bug or a feature?

 

[wksj]

It is Optimized battery charging. It charges to 100% when it thinks you are going to use the battery, and lowers to 80% otherwise. If you keep it on power all the time, it will learn and stay at 80% always, or you need to use some third party software.

 

[Mike Boreham]

My M1 Max 16" discharges its battery to 80% on a daily basis and charges it up to 100%. I can see it using the "Battery Power Bus" in iStat Menus when it's plugged in and idle. In two months it has already used 24 cycles even though it's been plugged in except for a handful of hours. I move it from room to room so it briefly loses AC a handful of times a day.

I have no problem with it staying at 80%. In fact, if I could force it to stop charging at 80% that'd be great. What I do have a problem with is needlessly consuming battery cycles.

Is this a bug or a feature?

Very strange. Is Optimised Battery Charging checked in the Battery Pref Pane. It is not supposed to do that but you could try unchecking it, or checking it (whichever it isn't).

You could also try the M1 equivalent of resetting SMC by shutting down, unplugging everything including power for 30 secs and rebooting.

Or you could use AlDente which gives you complete control, and I and many others here use. Lots of threads about it.

 

[Mike Boreham]

It is Optimized battery charging. It charges to 100% when it thinks you are going to use the battery, and lowers to 80% otherwise. If you keep it on power all the time, it will learn and stay at 80% always, or you need to use some third party software.

It doesn't sound like normal Optimised Battery Charging behaviour to me. A mostly plugged in mac should not be going to 100% like that.
https://support.apple.com/en-gb/HT212049

It may be that moving it from room to room is confusing the AI that determines behaviour.
I strongly recommend AlDente, as above.

 

[AdriftAtlas]

Very strange. Is Optimised Battery Charging checked in the Battery Pref Pane. It is not supposed to do that but you could try unchecking it, or checking it (whichever it isn't).

You could also try the M1 equivalent of resetting SMC by shutting down, unplugging everything including power for 30 secs and rebooting.

Or you could use AlDente which gives you complete control, and I and many others here use. Lots of threads about it.

Optimized Battery Charging is checked. Not quite sure how it's extending battery life by needlessly using the battery.

 

[Mike Boreham]

Optimized Battery Charging is checked. Not quite sure how it's extending battery life by needlessly using the battery.

As I said it doesn't sound like it is working correctly, or it is confused by frequent unplugging/re plugging for your room to room moves.
My M1 MBAs are plugged in most of the time, but OBC has never worked for me. On my first machine I gave it two months to start working before I started using AlDente. OTOH many people say OBP works for them.

 

[leman]

Optimized Battery Charging is checked. Not quite sure how it's extending battery life by needlessly using the battery.

Battery health deteriorate faster when they are left at full charge for prolonged period of time. Batteries need regular (light) cycling to stay healthy.

 

[Mike Boreham]

Battery health deteriorate faster when they are left at full charge for prolonged period of time. Batteries need regular (light) cycling to stay healthy.

Yes but OPB shouldn't result in 24 cycles in a few weeks.
My M1 MBAs are plugged in nearly 24/7 and have done 61 cycles (since Nov 2020) and 22 cycles (since March 2021). Apple Battery Health is 100% on both, and ioreg health as used by the third party apps, is 94.7% and 99.4%.
I use AlDente to keep max charge below 60%.
Standard advice for li-ion batteries not being used is to store them at about 50%.

 

[leman]

Yes but OPB shouldn't result in 24 cycles in a few weeks.

Wouldn’t it depend on how the machine is used? It’s a different battery capacity and also the power system and power requirements are different. I don’t see any problems with 12 cycles per month. It will take around 10 years to reach the battery cycle design limits at which point the battery will long be toast anyway.

 

[boak]

The Mac also charges up to 100% if you have an event scheduled in Calendar, not just AI learning your habits.

 

[Mike Boreham]

Wouldn’t it depend on how the machine is used? It’s a different battery capacity and also the power system and power requirements are different. I don’t see any problems with 12 cycles per month. It will take around 10 years to reach the battery cycle design limits at which point the battery will long be toast anyway.

I agree. If your usage needs cycles then that's fine. Many people use the machine on battery by day, and charge by night which would be at least 12 cycles per month. I am just surprised that a machine which is not being used like that and which that the OP says is mostly plugged in, has got 24 cycles already.

 

[Pro_the_legend]

It is optimized battery charging. It’s not great at learning the schedule you use your computer. I mostly keep my MacBook Pro M1 plugged in at home, and it would stop at 80%. However, the one day I go out and take my laptop with me, it ‘forgets’ my schedule and keeps doing what it does to you & puts unnecessary cycles on my battery. I stopped using optimized charging and just installed Aldente. Much better.

 

[JPack]

It's working as expected. If you didn't disconnect from AC, the computer would remain at 80% because you don't use the battery. However, you're disconnecting and reconnecting. In this case, MacBook has no idea how much you actually need the battery. As a result, it's trying maintain battery health by discharging to 80% but charging back up to 100% in case your next disconnect is long.

 

[doolar]

It takes quite a while to settle I've noticed. My personal Mac is mostly plugged in. I just traded my M1 Air for a 14" Pro, and I guess I have to wait for around 2-4 weeks before the new Mac learns my usage.

All this based on how long it took for my Air, I really had remembered the feature until one day I had 80% battery and the battery status said something like "You are using your computer on power bla bla" and there's a button for "charge full now".

 

[appleArticulate]

It is Optimized battery charging. It charges to 100% when it thinks you are going to use the battery, and lowers to 80% otherwise. If you keep it on power all the time, it will learn and stay at 80% always, or you need to use some third party software.

Lol, no. It does not do that at all. I use mine plugged 99.9% of the time and it never drains the battery while plugged in. Ever. And yes optimize charging is enabled.

 

[Pro_the_legend]

Lol, no. It does not do that at all. I use mine plugged 99.9% of the time and it never drains the battery while plugged in. Ever. And yes optimize charging is enabled.

You have to keep it plugged in for over 2 weeks for it to do this, but it is optimized charging. The worst part is even if it does it after you keep it plugged in over 2 weeks, if you remove the laptop for the charger even once, it'll reset the 'memory' and it'll keep doing what the OP's post says... It'll go to 100% and randomly drain to 80% and charge back up, and that's how the cycle continues.

 

[Mike Boreham]

.....or just use AlDente ....removes all uncertainty and waiting, and gives much more control instantly. I waited two months with my M1 MBA plugged in nearly all the time and OBC never worked.

 

[Reggaenald]

It is Optimized battery charging. It charges to 100% when it thinks you are going to use the battery, and lowers to 80% otherwise. If you keep it on power all the time, it will learn and stay at 80% always, or you need to use some third party software.

Exactly. It is a feature.
You’re charging your Mac wrong… no no, Optimized Charging is just very stupid and not optimized for use cases and scenarios like these because no one in Cupertino works like that or thinks about it. Just turn off OBC and you should be good.
My MBP also does funny stuff like this, you and your Mac aren’t alone in your confused state of silent suffering and senseless ageing.

 

[branchus]

Mine is a 14 inch pro, with 32GB RAM and 1TB storage, recently I found this same thing. but not to 80%. mine go down from 100% to 90% then recharge to 100%. very strange.

but I don't care, I normally using AC all the time.

 

[haginile]

Mine is a 14 inch pro, with 32GB RAM and 1TB storage, recently I found this same thing. but not to 80%. mine go down from 100% to 90% then recharge to 100%. very strange.

but I don't care, I normally using AC all the time.

Identical behavior on mine (16 inch MBP). Discharges to 90% and then charges back to 100% immediately. Happens every 28-30 hours or so.

 

[haginile]

Exactly. It is a feature.
You’re charging your Mac wrong… no no, Optimized Charging is just very stupid and not optimized for use cases and scenarios like these because no one in Cupertino works like that or thinks about it. Just turn off OBC and you should be good.
My MBP also does funny stuff like this, you and your Mac aren’t alone in your confused state of silent suffering and senseless ageing.

I'm not disconnecting mine at all, and it's still doing this daily. I kept thinking it'll eventually just settle down to 80% and hold there, but it's been over a month. Always plugged in, and yet every day it discharges to ~90% and then immediately charges back to 100%.

I spoke with a senior advisor, who agrees that this sounds like neither Optimized Charging (which predicts when you need 100% charge and wait for optimal time to charge back up) nor Battery Health Management (which may reduce total charge level to say 80% to extend battery longevity). Even tried escalating this to engineering. They came back and told me to do a clean install, which I did. This discharging happened WHILST the system was being re-installed, so it feels like this is something baked deeply into the firmware...


Things I've tried so far –
1) Disabling Optimized Charging;
2) Deleting content in /private/var/db/powerlog, /private/var/db/powerUI, which cleared out the battery histories, hoping a retraining of whatever model smart charging uses would occur;
3) Reinstalling the OS;
4) Using a different set of power adapter + magsafe cables.
5) Forced a few full discharges.
None of these worked.

BTW I think this only started happening after I re-installed the OS after 12.1 came out. Before 12.1, the system did hold the charge level at 80% after a while. So it's possible it's a new, undocumented behavior. Or it's a bug...

 

[haginile]

I'm not disconnecting mine at all, and it's still doing this daily. I kept thinking it'll eventually just settle down to 80% and hold there, but it's been over a month. Always plugged in, and yet every day it discharges to ~90% and then immediately charges back to 100%.

I spoke with a senior advisor, who agrees that this sounds like neither Optimized Charging (which predicts when you need 100% charge and wait for optimal time to charge back up) nor Battery Health Management (which may reduce total charge level to say 80% to extend battery longevity). Even tried escalating this to engineering. They came back and told me to do a clean install, which I did. This discharging happened WHILST the system was being re-installed, so it feels like something baked deeply into the firmware.


Things I've tried so far –
1) Disabling Optimized Charging;
2) Deleting content in /private/var/db/powerlog, /private/var/db/powerUI, which cleared out the battery histories, hoping a retraining of whatever model smart charging uses would occur;
3) Reinstalling the OS;
4) Using a different set of power adapter + magsafe cables.
None of these worked.

BTW I think this only started happening after I re-installed the OS after 12.1 came out. Before 12.1, the system did hold the charge level at 80% after a while. So it's possible it's a new, undocumented behavior. Or it's a bug...

 

[Menneisyys2]

My M1 Max 16" discharges its battery to 80% on a daily basis and charges it up to 100%. I can see it using the "Battery Power Bus" in iStat Menus when it's plugged in and idle. In two months it has already used 24 cycles even though it's been plugged in except for a handful of hours. I move it from room to room so it briefly loses AC a handful of times a day.

I have no problem with it staying at 80%. In fact, if I could force it to stop charging at 80% that'd be great. What I do have a problem with is needlessly consuming battery cycles.

Is this a bug or a feature?

Exactly the same here (I always keep my 16" on charger). After a while, I got fed up with wearing out my battery and just disabled Optimized charging. No such probs after that.

 

[Menneisyys2]

The best would be just allowing the battery to be constantly at 80% with an MBP always kept on AC. No constant charging/discharging. I wonder if there's some kind of a hack of doing it?

BTW, iOS (at least iPhones) do this much better - it indeed properly found out I start needing the phone at around 5-6AM and indeed finishes charging just before that. No constant dis-/recharging when on AC.

 

[Mike Boreham]

The best would be just allowing the battery to be constantly at 80% with an MBP always kept on AC. No constant charging/discharging. I wonder if there's some kind of a hack of doing it?

Yes it's called AlDente, as mentioned twice above. Been using it on two M1s very satisfactorily.