Optimized Battery Charging not working on MacBook Air M3

Adil300 wrote:

... leaving my laptop plugged in when I use it. I disconnect the charger when I close the lid if I'm finished with work and I don't shut the laptop off completely - as advised by the tier 2 agent. On the weekends I don't use my laptop and if I do (max 30-60 mins) I don't plug it in.

...

On the weekends I don't use my laptop and if I do (max 30-60 mins) I don't plug it in.

I use my laptop all the time from home, I always used it on battery. Plugged in the charger at 20% and disconnected it at 80%. That's how I've been rolling for a year.

Since you were constantly exercising the battery between 20% and 80%, I would assume that the battery health algorithm takes note that this laptop is used a lot running from the battery and hence tries to charge up to 100% when it can. There would be no need to keep it at the 80% level because you are making the battery discharge and charge repeatedly. The 80% target level is typically for laptops that are almost never running from the battery.

Also, your practice of disconnecting from power and sleeping when not in use, as well as not connecting to power on weekends, would further discharge the battery a small amount on a constant basis. Such a pattern would replace the need to target the 80%.

So operating your laptop in this way means that the 80% level won't be targeted, it's not necessary when the laptop is regularly running on the battery.

This is not a bad thing. The 80% target is only really for those who never exercise their laptop battery and always leave it plugged in.

P.S. As LeroyDouglas noted, the "learning" of a new pattern can take more than 14 days. His took 23 days. Mine took several months, as I recall.

I think what you see is normal and makes sense. Your battery seems healthy. It's not something you need to worry about. Well, you can if you want to but it will serve no purpose.

I agree with the other very experienced posters here (which is also what Apple recommends) ... what makes sense is to connect to wall power whenever it is convenient and available. Leave it on wall power when sleeping, on weekends, whenever. The system will manage the battery health.

Best advice is to not overthink this. The best practice is to plug into power whenever it’s convenient and run on battery only when you cannot connect to power. Your Mac uses Optimized Battery Charging, which is enabled by default. That is designed to charge the battery in a way that balances increased battery lifespan with your personal usage patterns. 

About battery health management in Mac notebooks - Apple Support

To confirm that Optimized Battery Charging is enabled, go to System Settings > Battery then click the (i) to the right of Battery Health.

If your Mac is usually plugged in, macOS will pause charging at 80% full since that’s better for the battery long term. If you frequently run on battery, macOS will charge the battery to 100%. That behavior will change depending on your usage. For example, I use my work MacBook Pro connected to a dock for most of the week, and charging pauses at 80%. If I run on battery a few hours for a couple of days, it will start charging to 100%. If I then keep the Mac plugged in for a couple of days, it will again pause at 80%. When your Mac decides to hold the battery at 80% charge, it will bring it to that level even if the battery is fully charged and the Mac is connected to power, which is what one of my Macs did here:

If charging is paused, you can override that by clicking on the Battery icon in the Menu Bar or Control Center (you may need to enable that in System Settings > Menu Bar) and select Charge to Full Now.

Once ‘trained’ the system is pretty responsive. For example, when my Mac was holding at 80%, a couple of short (30-45 minute) sessions running on battery one morning was sufficient to have macOS decide it was time to bring the battery to a full charge.

The bottom line is that your Mac will manage its battery charging to preserve the health of the battery while supporting your usage patterns. There's no need to micromanage it, let macOS handle it.

I typically use my personal Mac, a 16" M4 Pro MBP, connected to a dock, with very occasional use elsewhere in the house for a few minutes or a couple of hours. The Mac is 11 months old, has 14 cycles on the battery and the battery health is 102%. I typically use my work Mac, a 16" M1 Pro MBP, connected to power but 1-2 days a week I will run for a couple of hours on battery, and 1-2 times per year I will use it mostly on battery for a few days (scientific conferences). That Mac is 3.5 years old, has 196 cycles on the battery and the battery health is 93%. 

I've used Mac laptops since the PowerBook days, my experience has been that health drops from ~100% (my new Macs have mainly ranged from 98-104%, I did have one that started at 112%) to somewhere in the 88-93% range over the first 100-200 cycles (or 2-3 years, whichever comes first), then stay in that range for several hundred more cycles (or 3-4 years, whichever comes first) until they begin their inevitable decline at (with more recent Macs) between 800-1000 total cycles (or 7-8 total years, whichever comes first).

Note that there is both a usage and an absolute time component to battery longevity, even with very little actual use a battery has a finite lifespan, that's down to the chemistry in the battery that stores the power. 

Adil300 wrote:

But I'm not running regularly on the battery this way; I don't plug in the charger for small tasks over the weekend (99% of the time I don't use my laptop on the weekend). And honestly closing the lid while I'm done with work reduces like 1% of battery over 24 hours if not over 35 hours - it's minimal and it's what the apple support tech advised me.

I feel like the apple tech is advising me one thing and you guys are advising me another haha, or maybe I'm just getting confused. Also I'd rather not keep my laptop plugged in all the time at night, because of unnecessary power usage and thus a higher bill :)

"Tl;dr talked with apple support T2. Did everything they asked me to, function still doesn't work.

Will contact Apple T2 again next week since it's now weekend. Any advice? "

if you have an on-going issue take it in.

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment

Make an appointment for a "hardware issue"

Genius Bar Reservation and Apple Support Options - Apple

Outside the USA

Contact Apple Support - Apple Support

From iOS device using the "Apple Support.app” to make a online Genius Bar appointment is easy:

https://itunes.apple.com/us/app/apple-support/id1130498044?mt=8

Adil300 wrote:

I use my laptop all the time from home, I always used it on battery. Plugged in the charger at 20% and disconnected it at 80%. That's how I've been rolling for a year.

So you've spent a year training your Mac that you use it on battery most of the time. It's going to take a while of using it plugged in all the time for it to 'unlearn' what it has learned.

My battery health is now at 97% and 98 cycles.

Your battery is in great shape and you have nothing to be worried about. Going forward, just plug in if you're near an outlet and run on battery if you're not. That's really it.

Here is Apple's guidance on the subject.

Batteries - Maximizing Performance - Apple Support

About battery health management in Mac laptops - Apple Support 

If battery charging is paused or on hold on your Mac - Apple Support

In a nutshell, to get the most from your battery:

• Let the OS and charging circuits manage the charging.

• Plug in when using the computer near available power.

• Use on battery when ac is unavailable or when you must be mobile.

• Don’t subject the computer and battery to extreme temperatures.

• Don’t allow the battery to regularly discharge deeply before plugging in. Yes, it may happen from time to time, just don't make it a habit.

• Don't obsess over battery life and/or health.  

❝Worry is the misuse of imagination.❞ – Zadra

Adil300 wrote:

Update:

Been meaning to reinstall my OS, so I reinstalled OS over the weekend to also redo the learnings. Starting this week I'm already using my laptop plugged in all the time. So I guess now in 14 days time it'll learn 'the right way'.

Good computing Adil300 .

Last time I used my MBP on battery over a week vacation and charging to 100% over the course of the that week...

then when back on my desk full time plugged in, it took exactly 23 days for the battery to come back down to the 80% hold.

I'll be interested in your experience...

Adil300 wrote:

Agree on the worrying part, but I just want a function to work like it's supposed to - that's all.

If you spent a year using your slippers as a tug-of-war toy with your dog, then decided you didn't want the dog chewing on your slippers anymore, would you expect that a firm "No" for a few days would modify the behavior you spent a year encouraging?

Your Mac is working like it's supposed to. It is supposed to learn from your usage habits. Your long-term attempt to micromanage the battery charging behavior has trained it to do exactly what it's doing, keep your battery at 100%.

Adil300 wrote:

Agree on the worrying part, but I just want a function to work like it's supposed to - that's all.

As of now my laptop is still charging at 100%, instead of dialing it down to 80% and keeping it there.

The function IS working like it's supposed to.

And it's likely to continue charging as it currently is for some time before changing.

Adil300 wrote:

I use my laptop all the time from home, I always used it on battery. Plugged in the charger at 20% and disconnected it at 80%. That's how I've been rolling for a year.

Agree on the worrying part, but I just want a function to work like it's supposed to - that's all.

As of now my laptop is still charging at 100%, instead of dialing it down to 80% and keeping it there.

Yea that is exactly what you are not recommended to do...micro-managing battery charging, when in reality you can leave it plugged in all the time.

It can take upwards of 3 full weeks if not 4 weeks before you would expect to see a change. Nothing new here.

80% is not static, it is dynamic— let the software work for you.

The rule of thumb—if you are near the mains leave it plugged in, if you need the portability then run on the battery only—this is how you help optimize your battery charging and extend the working life of your battery by reducing the cycle count.

Adil300 wrote:

Doesn't the learning reset when you turn on/off optimized battery charging?

Yes moving forward I'm always plugging it in whenever I'm stationary working (100% of the time from my desk at home haha).

Won't the fact that I'm now keeping the charger plugged in at all times (to fix the learning phase) harm my battery long term? On the occassion that I do have to work without plugging the charger in, I would like the laptop to last me a couple of hours.

Btw, what kind of battery life are you getting just from using internet/nothing heavy on your laptop? Mine is lasting shorter than 6 hours when just browsing the internet.

No, it learns over time. Toggling the setting does not reset anything. The algorithm is a black box as far as users are concerned, but assuming you had optimized charging enabled (which it is by default) then as I said you have spent a year training your Mac that it should keep itself at 100% because you run on battery almost all the time and usually run down to 20% remaining charge. It would not surprise me if it wakes several weeks of leaving it plugged before it starts to hold at 80%.

Keeping it plugged in all the time won't harm anything.

To reiterate: stop worrying about this. Plug in when you can, run on battery when you need to. If/when it starts holding at 80%, if you know you'll be running on battery for several hours then you can click the battery icon (menu bar or control center) and tell it to 'charge to full now'.