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RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
Hello.
The energy saving feature (the one which controlled charging till 80%) never worked for me, until yesterday.
Finally yesterday it started functioning as it should, almost 2 years after starting working with the Mac.

Does anyone know why did it happen like this?

Ty,
Rafael
 

Spaceboi Scaphandre

macrumors 68040
Jun 8, 2022
3,414
8,106
That's normal. Optimized Battery Charging is designed to prevent wasted battery cycles from constantly charging. So if you infrequently charged before hand it would charge you to 100%, but if you're someone who leaves their Macbook plugged in most of the time (like me as mine rarely leaves it's Magsafe cable) then you'll usually be at 80% to prevent wasting cycles.
 
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RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
That's normal. Optimized Battery Charging is designed to prevent wasted battery cycles from constantly charging. So if you infrequently charged before hand it would charge you to 100%, but if you're someone who leaves their Macbook plugged in most of the time (like me as mine rarely leaves it's Magsafe cable) then you'll usually be at 80% to prevent wasting cycles.
Yes, but my question is: why just now? I'm using the Mac like this for about two years, can't understand why this feature just started functioning now.
 

Spaceboi Scaphandre

macrumors 68040
Jun 8, 2022
3,414
8,106
Yes, but my question is: why just now? I'm using the Mac like this for about two years, can't understand why this feature just started functioning now.

Well were you leaving your Macbook Air unplugged a lot? If so, there's your answer. It picks up on your charging habits and optimizes accordingly to maximize battery longevity as much as possible.
 

RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
No, I'm using it like I ever did. The option was selected since it I had bought it. It is very odd to me!
 

ignatius345

macrumors 604
Aug 20, 2015
7,574
12,923
No, I'm using it like I ever did. The option was selected since it I had bought it. It is very odd to me!
I wonder if it got triggered by the number of battery cycles you've gotten to? I'm speculating here and may be way off base, but maybe when your battery gets to a certain point it's more sensitive to charge level vis a vis wear on the chemistry.
 

MrCheeto

Suspended
Nov 2, 2008
3,531
352
My MacBook Air isn’t even one year old and it has done the half-assed charging since day one. I actually have to beg it to charge fully. Can’t tell you the number of times I’ve gone to work thinking it’s charged, since I had it plugged in for 10 or more hours, only to find it at 80% or below! I’m tired of having Cupertino decide to stick their nose into so many aspects of my daily life and nag or nanny me.

What’s weird is I remember it would say “will fully charge by 4am” in the menu but I had the option to “charge to full now” right below it. That option is gone!!! WTF!?

To add to OP’s troubleshooting, keep in mind that it charges on a schedule. From what I remember, it charges to 80%, waits until around the time you normally unplug it, then charges fully at that determined time.

I truly do wish to reduce wear on my battery but with this level of Cupertino insanity it just almost won’t be worth it.
 

raythompsontn

macrumors 6502a
Feb 8, 2023
763
1,064
My M2 Air was at 92% when I plugged in the charger. A couple hours later the charge is at 80% and holding. The charge will increase to 100% about 06:00. Being on the charger the M2 Air actually discharged during those two hours while I was not using the device.

It appears the MacOS does a good job of maintaining the battery without 3rd party apps. Additionally, does anyone really know if the 100% level is really 100% of the battery capacity? Does the MacOS firmware keep the battery at say 90% of actual capacity which MacOS reports as 100% available energy?
 

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MrCheeto

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Nov 2, 2008
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Would you feel short-changed if you weren’t getting that final 10% of battery? Since I’ve started using A64 Macs, I’ve basically stopped even caring about battery. It always has life as long as I need and I plug it in over the weekend, assuming it was at 100% at the start. If somebody exposed Apple for withholding 10% of the life I’m already getting, I’d still sleep pretty good.

AFAIK, almost no modern devices use 100% of the li-on capacity. Those that do might be the ones that explode under the Christmas tree while charging 😬

It’s just like engines. Unless it’s a strictly performance car (Ferrari, McLaren), it probably is only making 70-85% of what the engine internals were designed to withstand which is a positive for durability. My car supposedly outputs 250hp but the internals easily handle 430hp…but probably for not as long as the stock condition.

Strangely, my MBA only charged to 100% this morning at 6am like yours 🤔
 

raythompsontn

macrumors 6502a
Feb 8, 2023
763
1,064
Would you feel short-changed if you weren’t getting that final 10% of battery?
Not if it prolongs the life of a basically not-replaceable battery. An extra year of serviceability of the laptop is more important than 30 minutes of extra battery life.

In all my years of owning laptops I have never run out of battery. I am usually close to an outlet or some sort of power supply. I have 110V available in my vehicle. I had 110V available on a long airline trip. I had 220V available on a long train trip in Europe.

Tesla derates their batteries as on more than one occasion during a natural disaster, Tesla has pushed out firmware updates that extends the amount of battery that can be used. Allowing more discharge, perhaps making higher charge levels.

my MBA only charged to 100% this morning at 6am like yours
Mine has done this charge process several times. When it does this I have not fully figured out. What surprised me was discharge down to 80%. The M2 was not in use same as the prior period in the graph. Basically no discharge. I plugged in the laptop, closed the lid and did not open until this morning. What caused the discharge is unknown.

At this point with current technology and firmware smarts, I no longer concern myself with the battery. I plug the laptop in when it needs charging, pull the charge cable when I take the laptop. I don't even think about it anymore.
 

MrCheeto

Suspended
Nov 2, 2008
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352
It’s a great feeling and not something I could really enjoy with Intel chips no matter how much marketing hyped. A64 power management is a dream.

Batteries should be “worked out” to stay healthy. You don’t have to work out every single particle of the cell, just move some then move others etc.

All batteries, practically, work by moving electrons to form and break up molecules. I imagine that “wear” is a result of the fact that no chemical reaction is really 100% efficient, thus the chemicals you have at the start won’t exactly be the same chemical elements in the end. There’s no loss of matter but it may have combined into something else or not reacted at all.

By discharging the battery to 80%, the Mac forced the Lithium to shuffle around from cathode to anode and back, thus giving them a workout but not to the extent of a full discharge. I have seen lithium chargers advertise a “battery tender” mode that essentially does just this: a shallow re-jiggling of the molecules to keep them plastic or homogenous.

I’m not a chemist but this Sesame Street level of understanding is good enough for me 😅 I just want my “Charge Fully Now” button back
 
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raythompsontn

macrumors 6502a
Feb 8, 2023
763
1,064
I have seen lithium chargers advertise a “battery tender” mode that essentially does just this
The batteries for my EGO yard tools, while on the charger, will be discharged to 20% and hold that level if not used for 30 days. Before using the batteries I remove them from the charger and reinsert after not being used for the winter. That brings the batteries up to 100% of available charge in about an hour. There is a fan in the charger that blows air through the battery pack to keep the batteries cool.

The batteries have to be on the charger for the discharge to be accomplished. It is actually the charger that is discharging the battery through some load resistor that is fan cooled.
 

RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
I wonder if it got triggered by the number of battery cycles you've gotten to? I'm speculating here and may be way off base, but maybe when your battery gets to a certain point it's more sensitive to charge level vis a vis wear on the chemistry.
I don't know, I'm at 105 right now. Could it have started at 100? Not in my case, as since I've wrote I haven't made an entire cycle.

Thank you @MrCheeto and @raythompsontn. I wonder if it was the changes on privacy (in System Preferences) that activated this service. Days ago I enabled privacy settings (namely the localization, because I wanted to automatically adjust the hours during a trip I've made). I kept those settings. Does the Mac now knows when I'm using the charger at home/office and controls the charging timings?
 

JPack

macrumors G5
Mar 27, 2017
13,469
26,071
Enabling Location Services likely enabled Optimized Battery Charging. Even though it's much more healthy, Mac doesn't want to cap the battery to 70-80% if you're working away from home.
 
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RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
Not if it prolongs the life of a basically not-replaceable battery. An extra year of serviceability of the laptop is more important than 30 minutes of extra battery life.

In all my years of owning laptops I have never run out of battery. I am usually close to an outlet or some sort of power supply. I have 110V available in my vehicle. I had 110V available on a long airline trip. I had 220V available on a long train trip in Europe.

Tesla derates their batteries as on more than one occasion during a natural disaster, Tesla has pushed out firmware updates that extends the amount of battery that can be used. Allowing more discharge, perhaps making higher charge levels.


Mine has done this charge process several times. When it does this I have not fully figured out. What surprised me was discharge down to 80%. The M2 was not in use same as the prior period in the graph. Basically no discharge. I plugged in the laptop, closed the lid and did not open until this morning. What caused the discharge is unknown.

At this point with current technology and firmware smarts, I no longer concern myself with the battery. I plug the laptop in when it needs charging, pull the charge cable when I take the laptop. I don't even think about it anymore.
sorry if this question seems dumb: what happens, for instance, if your Mac is plugged with the energy saving mode (on 80%) and you decide to turn it off (still plugged in)? Will it charge to 100% or will it maintain 80%?
 

JPack

macrumors G5
Mar 27, 2017
13,469
26,071
sorry if this question seems dumb: what happens, for instance, if your Mac is plugged with the energy saving mode (on 80%) and you decide to turn it off (still plugged in)? Will it charge to 100% or will it maintain 80%?

Maintain 80 %
 
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RaphaZ

macrumors 6502
Original poster
Dec 2, 2021
258
79
So, for a considerable amount of time, the energy saving wasn't functioning.
I don't know what I did (if I did something), but two weeks ago it started working properly.
Now I can be anywhere and it only charges until 80% (or more if I select the option).
Was there some function or code that kept the MB without this energy saving?
It is really strange, but at least after two years it works!
 

jdb8167

macrumors 601
Nov 17, 2008
4,854
4,594
So, for a considerable amount of time, the energy saving wasn't functioning.
I don't know what I did (if I did something), but two weeks ago it started working properly.
Now I can be anywhere and it only charges until 80% (or more if I select the option).
Was there some function or code that kept the MB without this energy saving?
It is really strange, but at least after two years it works!
Has there been a change in your daily schedule? I've found that if you have a fairly random charging schedule, optimized battery charging never kicks in. Also, make sure you understand what OBC really does. I charge my M2 MacBook Air every day after work. I take it off the charger at usually the same time (around 9AM). It always shows 100% charged but if I look at the Battery Settings Panel, I usually see that it charged to 80% stopped charging and then around 6AM it finished charging to 100%.

For my purposes, I just trust that Apple is doing the best they can with their algorithm for optimized charging but many people want more control so they use something like Al Dente.
 
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JPack

macrumors G5
Mar 27, 2017
13,469
26,071
So, for a considerable amount of time, the energy saving wasn't functioning.
I don't know what I did (if I did something), but two weeks ago it started working properly.
Now I can be anywhere and it only charges until 80% (or more if I select the option).
Was there some function or code that kept the MB without this energy saving?
It is really strange, but at least after two years it works!

If after two weeks, it doesn't kick in, it might be buggy. Follow these steps to turn it on:

https://www.reddit.com/r/macbookpro/comments/yjjggs
 
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JPack

macrumors G5
Mar 27, 2017
13,469
26,071
If that actually fixes it then that's ridiculous Apple. One of the features of the M-series SoCs is that they are supposed to have an always on cpu. Having to decide to plug in the power cord only after booting on battery in order to get a feature to work is broken.

It worked for me a couple times after an macOS update where my computer stopped putting "charging on hold." Waited two weeks, nothing changed. Then I followed those steps and it fixed it after a few days.
 
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