MBP weird charging behavior

[Grumpus]

I'm seeing weird battery charging behavior on my new M3 MBP and I'm hoping someone here can help me decide whether it's due to a bug in
Sonoma 14.5, a problem with the power brick, or a hardware problem with the laptop. It's connected to power almost all the time, with a green light on the magsafe. Optimized battery charging is on, and there are less than a dozen cycles on the battery so far.

Periodically I will notice that the magsafe light has changed to amber, and the battery indicator in the top bar shows that the battery level has dropped to 96 or 97 percent. Clicking the battery icon shows the power source to be the power adapter and the battery not charging. Looking at the battery in System Settings, however, shows the battery to be charging at 96 or 97 percent.

When things get into this state, they stay that way as long as the magsafe is connected, surviving reboots and shutdowns. Turning optimized battery charging off 'until tomorrow' changes nothing.

If the magsafe is removed, the charge level indicators stay the same, no matter how long I wait, until the laptop is shut down and restarted,
after which the charge level might show anything between 25 and 99 percent, depending on how long I ran with the magsafe removed.

I ran hardware diagnostics and no problems were found. Searching the forums here turns up a lot of complaints about optimized charging, but nothing quite like what I'm seeing.

Am I alone in seeing this strange behavior? Is this hardware? Software? Besides "call Apple" can anyone offer any advice? Thanks!

 

[noblesoul117]

The stuck percentage, then sudden percentage change upon restart, sounds like a possible software issue.

However, the green-turned-amber situation might be normal, since you said it's connected to power almost all of the time.

I've recently been using my M2 MBA, connected to power almost all of the time. After a few days (not sure how many) the green light turned to amber and my battery charge dropped to 80%. This is part of the Optimized Charging.

So I wonder if you're experiencing half of a bug, and half of something normal? I don't know why it would only go to 96%. Maybe if Sonoma doesn't think you'll leave it plugged in forever, but still wants to prevent the battery from staying at 100%? Maybe it hasn't been consistently plugged in, for enough duration, to fully activate the 80% mode?

The Discrepancy between the Menu Bar and System Settings is weird for sure. Attached is what I see: "Charging on Hold: Desktop Mode."

Another app you can use to inspect battery info is CoconutBattery.

And if you wanted to try controlling the battery/charge settings yourself, there's AlDente.

 

[Grumpus]

Thanks for the reply. I've considered AlDente but don't want another variable until I'm sure it's not a hardware issue. Apple support had nothing, except to agree that it's a strange problem. The support rep insisted that I reinstall Sonoma. I did, but since the disk wasn't erased I doubt it helped anything. Now waiting to see what happens.

I've never seen Charging on Hold, even though the laptop stays on the charger pretty much 6 days out of 7, but I've had the laptop for little more than a month now. Maybe it takes longer.

 

[MacCheetah3]

Periodically I will notice that the magsafe light has changed to amber, and the battery indicator in the top bar shows that the battery level has dropped to 96 or 97 percent.

This is (mostly) expected behavior.

Clicking the battery icon shows the power source to be the power adapter and the battery not charging. Looking at the battery in System Settings, however, shows the battery to be charging at 96 or 97 percent.

When things get into this state, they stay that way as long as the magsafe is connected, surviving reboots and shutdowns.

This is somewhat strange.

For the most part masked by Apple, the power management system will take several actions with the battery, some dependent on settings:

• When the battery charge indicator reports 100% or fully charged, the battery may continue to charge for a brief time longer. Basically, this is because of the nature of current battery tech, chemical reactions that are volatile to many conditions, and the subsequent difficulty to consistently, precisely measure the state. In other words, the system may detect the battery (in its current condition) is capable of supporting more charge than the previously measured 100% capacity. You can witness the behavior via apps such as coconutBattery.
• Also when the battery reaches full charge, the system will stop charging the battery. The state-of-charge will continue to be monitored until it drops to ~95%, at which point charging will restart. The cycle will repeat until the device is disconnected from external power. When Optimized Charging is enabled and engaged/active, the cycle happens from ~75 to 80%. This helps to prevent overcharging.
— You might catch this behavior when the system finally updates the level, which can happen when the state-of-charge measurement drops a percentage after disconnecting from the external power source or a device restart/reboot. For example, you disconnect the device from power with the battery indicator showing 100%, although, the charge level is actually measured at 98. You use your device (on battery power), and when the state-of-charge drops to 97% the reported percentage is finally updated (i.e., jumps from 100% to 97%).*
• From ~80 to 100%, the system will step down the charge rate, slowing to a trickle charge. On the other side of the spectrum, at <5% or so battery level, the system will throttle down components (i.e., you’ll probably experience some lag).

* I know it’s not your exact scenario, however, another reason reported battery state-of-charge may jump, device may unexpectedly shut down, and/or the battery health/capacity may not have changed for a very long period is loss of calibration.

Battery Calibration

All newly-installed smart batteries should be calibrated as soon as possible. This helps your phone or laptop get an accurate reading on the battery’s state of charge.

www.ifixit.com

iPhone Keeps Shutting Off Randomly? Easy Fix!

Your iPhone is shutting itself off randomly and you don't know why this happens. The shutdown problem doesn't have to ruin your day. Read on to find out easy and quick fixes so iPhone stop shutting down for no reason.

www.appgeeker.com

— (Re)Calibration also ‘fixed’ my brother’s aging iPhone XR, which he described as laggy when nearing ~30% battery and would then shut down.

Battery Heath Dropped 10% After Calibration

Last night I calibrated my battery. Let it fully charge for 2hrs, took it off the charger, turned up the screen brightness and keyboard backlight all the way, then proceeded to run the battery down watching videos and whatnot. It went to sleep and I went to bed to let it sit for 5 or more hours...

forums.macrumors.com

An iPhone battery can last much more than 1000 cycles!!!

Ok so now I calibrated the battery once and the coconutBattery health aligned to battery health of the settings app. It displays 90% now, which should be the real SoH. And not the 100% from before. This shows that an uncalibrated battery management system can show a false health value for the...

forums.macrumors.com

 

[Grumpus]

• Also when the battery reaches full charge, the system will stop charging the battery. The state-of-charge will continue to be monitored until it drops to ~95%, at which point charging will restart. The cycle will repeat until the device is disconnected from external power. When Optimized Charging is enabled and engaged/active, the cycle happens from ~75 to 80%. This helps to prevent overcharging.

Thanks for that! This may be what's going on, although optimized battery charging is on and I never see the charge level drop to/below 80%, and I've never seen the 'charging on hold' status. It's also confusing that the reported charging status in the topbar icon popup and Battery panel in System Settings don't agree with each other. It's not comforting that the Apple support rep was as confused as I am

This weekend I'll go through the steps recommended by iFixit to calibrate the battery.

 

[MacCheetah3]

although optimized battery charging is on and I never see the charge level drop to/below 80%, and I've never seen the 'charging on hold' status

That’s a whole other ball of yarn. Because the feature uses ML, it’s most reliable when exposed to rigid schedules.

When the feature is enabled, your Mac will delay charging past 80% in certain situations. Your Mac learns your charging routine and aims to ensure that your Mac is fully charged when unplugged.

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

Use the battery status menu to resume charging if you need to have your Mac fully charged sooner.

support.apple.com

However, even then things can be unexpected. A couple of examples:

M1 Max 16" Battery Discharges to 80% and Charges to 100% Daily While on AC

My M1 Max 16" discharges its battery to 80% on a daily basis and charges it up to 100%. I can see it using the "Battery Power Bus" in iStat Menus when it's plugged in and idle. In two months it has already used 24 cycles even though it's been plugged in except for a handful of hours. I move it...

forums.macrumors.com

Optimized Battery Charging - Late

I have an iPhone 14 PM running 16.4.1 with Optimized Battery Charging (OBC) enabled and Clean Energy charging disabled. I wake up every day at the same time, and my phone would always be charged to 100% when left on the charger overnight. Even if I woke up 10 or 15 minutes before my alarm, the...

forums.macrumors.com

 

[Grumpus]

That’s a whole other ball of yarn. Because the feature uses ML, it’s most reliable when exposed to rigid schedules.

Although I use the laptop most days, my usage pattern varies. Also, if I'm in the middle of something at the end of the day, I'll simply close the lid and let it sleep, but if I'm done I power it down. That might affect the OBC algorithm. I've decided to turn it off to see if the flaky behavior stops.