16" MacBook Pro M1 Max Battery Management - always charging to 100%

I purchased this new 16" M1 Pro Max planning to leave it on my desk plugged in most of the time. I was depending on the battery managment in the system to keep the charge level at no more than 80%. However, it keeps the battery charged to 100%. Battery managent is checked in System Preferences. I have run it on battery a few times to get the charge under 80%, but it always charges back to 100%. My understanding was that keeping the charge to 80% max when plugged in would maximize battery life. Am I missing something?

It takes several days of consistent behavior per each 24 hour period. If you are doing something like unplugging it every third day, I don’t think it’s going to work (or at least not likely to–the ML is not perfectly predictable.)

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Here’s the TL;DR for Apple devices:

Just use it the way you want to use it.

For iPhone, iPad, iPod, Apple Watch, use them between 32° and 95°F (0° to 35°C).

For MacBooks, use them between 50°F and 95°F (10° to 35° C).

Store any device between -4° and 113°F (-20° and 45°C).

If you have a case on your device and it gets hot when you charge it, take the case off when you charge it.

If you’re storing it more than 6 months, charge it to 50%, and do so every 6 months.

What I wrote in more words direct from Apple.

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thanks for the help!

Thanks most appreciated!

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Does it make a difference if you use the MagSafe or a USB-C port to charge?

No difference—just as mobile charge optimization learns regardless of lightning port or Qi charger use.

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There’s an article about this in the latest Macworld.

That last 20% is a “trickle charge” which they say doesn’t add heat or overcharge the battery.

I’ve noticed the same thing on my Macbook M1 Pro and I can confirm that even when charging fully the machine remains cool – unlike my 2016 Macbook Pro.

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It took my Mac few weeks to understand my behavior and it’s connected 24/7 to get it self adjusting the battery at 80% and not charging it.

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Many thanks, I will give it more time.

Did you have to run it on battery to get it under 80% or did it just make the adjustment on its own?

As an additional data point, I used to observe my always connected late 2018 MBP charge only up to 80% but now it’s been 100% charged for a solid day.

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My M1 MBA stays plugged in 24x7 also. I do run it down to 30-40% 3 or 4 times a month but it always charges to 100%. I use it as a portable server so if I’m shortening its life I’ll just replace the battery as needed. Fortunately Apple just charges $129.

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I disconnected it once to use it, it went to 80% and it didn’t recharge back. As @JohnAtl mentioned, just use it and it will handle itself.

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That’s amazing. I’m a few decades in and still don’t understand my behavior.

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It took over two weeks, but is now working perfectly.

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