Optimised charging not working, 8 months, Macbook Pro M4 Max

musafarmanu wrote:

My usage is mostly connected to an external monitor(Dell UltraSharp 27 Thunderbolt™ Hub Monitor, U2724DE) with an inbuilt Thunderbolt hub. I use it with the Thunderbolt 4 cable, and it is always charging. It has been more than 8 months now, and it still has not learned to hold the charge at 80%. I have tried many things, such as using the Mac to turn down the charge below 50% and then charge again; macOS is also up to date. It does not seem to work.

Any help would be appreciated.

Are you plugged into power independent of the external monitor(Dell UltraSharp 27 Thunderbolt™ Hub Monitor.

I would try the magsafe or USBC charge cable plugged in direct to the Mac and compare your results.

There is no harm—the macOS manages the better power supply.

I would give that some time/weeks to see if the optimize battery charging responds to that stimulus.

it may well be hub/monitor related.

no harm here 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.

M1/M2/M3/M4 SoC

About battery health management in Mac notebooks - Apple Support

The current stable release of Tahoe including bug fixes, security updates is macOS 26

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

Battery Health Management feature tracks your usage history and detects that you do not generally run your battery down to low levels. So when you see less than 100 percent as a full charge, it is charging less than the highest level for longest battery lifetime.

NOTE that charging to 80 percent is a side-effect, NOT the GOAL.

The goal is to have some hurly-burly (percolating activity) around using your battery, either by your actually using it, or by leaving it less than fully charged, so that the cells are not 100 percent charged 100 percent of the time. Battery Health Management will also from time-to-time let the battery decline slightly to 'get some exercise' and run lower (thought to be around twice monthly) if you do not do so by your ordinary use.

The feature tracks you actual usage. If you continue to not require 100 percent charge for a few weeks, it generally will revert to a lower "full" level. but it takes some experience, which takes some time

If your recent usage patterns demand top battery capacity, the battery will charge completely to be sure you are not stuck out in the wild with no power.

Executive summary:

“If you keep your Mac plugged in continuously for several days, it will start pausing the charge at 80%. If you run a small amount of the time on battery, it will keep doing that. If you run some of the time on battery, it will charge to 100%.” © 2025 neuroanatomist

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

When you say 'mostly connected' what do you mean? If you run on battery for a little while every day or two, that's probably enough to prevent holding at 80%.

musafarmanu wrote:

Do you mean I should also plug in the 140W charger and connect to my Mac, with the thunderbolt cable connected?

If macOS manages the better power supply, does that mean it would not take the power input from the thunderbolt cable and will choose the power adapter?

Yes and yes.

Odd. I use my Mac (16" M4 Pro MBP) mostly connected to a Stone Pro 3 dock (it provides 85 W power) and mine usually holds at 80%.