why 'Charging on hold' , 'On Hold 80% battery'

[ewu]

16 inch M5 Max Macbook pro, Mac OS Tahoe 26.4.1. It always drains battery from 100% to 80% and on hold at 80%.

My Dell U2723qe provides 90W input from usb c to MBP, at beginning I think may be 90W is not enough and mbp didn't take magsafe 3 power
Then I change to hdmi cable to connect and left magsafe power only. but battery still go down.

adjust many settings such as battery/weak/sleep.
however, it seems that MBP on purpose want to drain battery from 100% to 80%

I google and ask chatgpt, result is 'Optimised Battery Charging'

It’s normal and good! Batteries do not like being constantly charged to 100%

my macbook pro M2 pro with Mac OS Sonoma don't have such issues.
but it shows that M2 Pro battery only 94% health after 3 years usage.

so I suspect it is a new feature of mac os Tahoe 26.4.

I start to use macbook pro since 2010, totally > 16 years, none of macbook pro has battery issue.
why we require such way to `Optimised Battery`

 

[Basic75]

none of macbook pro has battery issue

Would you have noticed your batteries degrading slightly faster because they were often at 100% as an "issue"?

 

[ewu]

Would you have noticed your batteries degrading slightly faster because they were often at 100% as an "issue"?

my M2 Pro mbp battery is 94% health after 3 years usage. battery will drain faster but power still acceptable in most of cases with battery only. I don't think it is an ssue.

After I turn off M5 Max macbook pro, it starts to charge battery based on power meter.
power meter shows that mbp take 50w to charge battery.
and then second day mbp drain battery from 100% to 80% again.

it looks like mbp is a big iphone. charging after mbp shutdown and drain to 80% when mac os turns on.

I could turn off `Optimised Battery` , but will new stratedgy benefit battery health in long term?

 

[Bigwaff]

I could turn off `Optimised Battery` , but will new stratedgy benefit battery health in long term?

Do you trust Apple? It’s in their financial interest to have batteries last as long as possible.

 

[Honza1]

This subject has been beaten to death over the last 5-10 years. Even AI knows the answer to this today and provides very good answer.
Apple is trying to help you - and it was others which implemented this first - Google AlDente.app and read some of their explanations. Apple is actually providing features AlDente provided for years now.
Short version : permanently charged battery may report 100% health while failing very quickly when you actually try to use it. It needs to be occasionally cycled to even know what the health is. Or you will be badly surprised when you eventually need it.

 

[ewu]

This subject has been beaten to death over the last 5-10 years. Even AI knows the answer to this today and provides very good answer.
Apple is trying to help you - and it was others which implemented this first - Google AlDente.app and read some of their explanations. Apple is actually providing features AlDente provided for years now.
Short version : permanently charged battery may report 100% health while failing very quickly when you actually try to use it. It needs to be occasionally cycled to even know what the health is. Or you will be badly surprised when you eventually need it.

haha, 5-10 years such long time discussion
battery and charging are key topic

 

[Honza1]

haha, 5-10 years such long time discussion
battery and charging are key topic

There is research on this subject going on at universities, national and company laboratories (for way more than 10 years), since proper battery management is safety and efficiency critical issue. Results are published in literature, peer reviewed, tested, and re-evaluated. You can check this yourself in publications.
Why do you think even more discussion on Macrumors web site, instead of just learning what these teams with extensive resources have discovered, is going to make any difference? This is issue of physics/chemistry which no amount of discussion will change. And the "learning" is exactly what chatGPT is good at ;-)

 

[ewu]

There is research on this subject going on at universities, national and company laboratories (for way more than 10 years), since proper battery management is safety and efficiency critical issue. Results are published in literature, peer reviewed, tested, and re-evaluated. You can check this yourself in publications.
Why do you think even more discussion on Macrumors web site, instead of just learning what these teams with extensive resources have discovered, is going to make any difference? This is issue of physics/chemistry which no amount of discussion will change. And the "learning" is exactly what chatGPT is good at ;-)

as I mention before, my m2 pro mbp which is 3 year old with mac os sonoma, it also turns on battery optimise. but battery never drain such way (forced drain from 100% to 80%). my 2019 Intel MBP with mac os sequoia don't have such optimised way. therefore, such optimised way do happen very recent years (around 2 or 3 years).

battery optimised way are different among mbp and different mac os. that is why I raise it. They have same name 'battery optimised', but behavior are different.

 

[Honza1]

as I mention before, my m2 pro mbp which is 3 year old with mac os sonoma, it also turns on battery optimise. but battery never drain such way (forced drain from 100% to 80%). my 2019 Intel MBP with mac os sequoia don't have such optimised way. therefore, such optimised way do happen very recent years (around 2 or 3 years).

battery optimised way are different among mbp and different mac os. that is why I raise it. They have same name 'battery optimised', but behavior are different.

Some of this may be hardware limits (some stuff may be implemented on very low levels) and some may be battery technology. We all call it Lithium ion battery, but there are many different technologies behind this generic term with VERY different properties and requirements. And new/improved/modified pop out in products few times each year... Apple does not really publicize the technology changes over time, which must be quite significant. I wonder when we get the solid state Li ion batteries like are coming out in Chinese cars now. Those will be game-changers as they are supposedly not burning on failure. Somehow useful for devices which fly as often as notebooks.

 

[MacCheetah3]

About Optimized Battery Charging and Charge Limit on Mac - Apple Support

To improve the lifespan of your battery, Optimized Battery Charging allows your Mac to learn from your daily charging routine so that it can delay completing a full charge in certain situations. And with Charge Limit, you can limit what your Mac considers a full charge.

support.apple.com

Your MacBook Pro is almost always connected to a power source (e.g., Thunderbolt monitor, charging “brick”), correct? So, what’s the problem with the battery charge being at 80% most, if not all of the time?

As others have pointed out and reminded (as well as the above linked article):

Optimized Battery Charging is designed to reduce the wear on your battery and improve its lifespan by reducing the time that your Mac spends fully charged.

The problem is not that your Mac or any device shouldn’t be charged to 100%. Rather, having a battery always or almost always at 100% most of its life is extra stressing on the cells.

Not the only reason, but a constantly full-charged battery is also far more common to swell.