Apple's Battery Health Management Feature Cannot Be Disabled on Apple Silicon Macs

[acidblood]

Based on the heat aspect it seems that induction (wireless charging) would be the battery killer as it is heat heat heat. What do you think of that?

All I can say is, I bought a wireless charger before researching this issue as deeply as I did recently, and haven't used it ever since.

 

[Carrotcruncher]

Does the use of M1 Chips mean replacing worn batteries will now mean a warning and the disabling of the optimised like the iphones ?

 

[jimbobb24]

All I can say is, I bought a wireless charger before researching this issue as deeply as I did recently, and haven't used it ever since.

Thanks a lot for the info. Very helpful and grateful for your research.

 

[rgbrock1]

This actually works? How? Is it by keeping the charge cycles of max to min from happening?

It interfaces with Apple's SMC and sets a max amount of charge the SMC allows the battery to receive. it's not 100% accurate but close. Example: if I set max charge to 70% it might charge it to 72% or even 73% but not more than that.

 

[MacBH928]

In my reading of the scientific literature, I've identified four main factors that, each to a different (and somewhat unknown) extent, will help in prolonging the lifetime of batteries. I'll list them in what I understand to be the order of importance, most important first.

(a) Avoid heat. Turn off the laptop when not necessary, and if performing intensive processing, ensure an adequately cooled environment, avoid blocking the fan ducts. If possible, periodically clean inside the computer -- I know from personal experience that a lot of dust accumulates there. Heat is the worst enemy of a battery

(b) Reduce the number of cycles in the battery. If you put enough cycles in the battery, it'll degrade, regardless of whether you do everything else right. You can only postpone the degradation, but not prevent it indefinitely. So the best thing you can do is -- if there's a nearby outlet, plug it in. Lately I've even been using a power bank to reduce the rate of discharge on my MacBook Pro while I'm away. Yeah, defeats the purpose of having a light, battery powered laptop -- I agree 100%. Problem is, Apple charges a fortune to replace the battery on the MacBook Pro, and I refuse to pay for that (it's the equivalent of 1.5 to 2 monthly minimum wages in my country, just so you have an idea), so I am forced to resort to desperate measures like this.

(c) Avoid keeping the battery at a high state-of-charge. 100% is awful, 80% is much better, 60% is just perfect. This is what the AlDente app does.

(d) Avoid charging and discharging at a high rate. This appears to be more important for very fast charge/discharge (say, when you deplete the whole battery in < 1 hour, or recharge it that fast, which is supported in the iPhone but not the Mac). Prefer to perform any CPU-intensive tasks with the battery plugged in. Ideally, you'd use an undersized charger to charge the computer overnight when necessary -- for instance, a 30W charger for the MacBook Pro. But at this point you may as well compete for the world record of battery longevity -- economically it makes no sense to buy another charger just for this, plus the benefits are just too small.

So to answer your question: your option (1) is awful because of my point (c), and yet basically it's what used to happen before optimized charging (at least in the Apple ecosystem). Option (2) is awful because of point (b) and also point (c) -- it's only good to ensure the gas gauge IC is kept calibrated, but otherwise you're needlessly wasting cycles. In fact, the recommendation to drain it periodically has to do, as far as I'm aware, with recalibrating the gas gauge IC. Option (3) is bad if you're purposefully connecting and disconnecting the power adapter to ensure this state of charge (because of point (b)). The "right" way to do this is using an app like AlDente which keeps it at a set state-of-charge indefinitely -- it just stops draining more power from the power adapter than is required to keep the battery at its current state of charge. So you can keep the power adapter on, and the battery won't charge. This is what I recommend doing. Apple's optimized charging tries to do something like that, but since it assumes you'll need the battery at 100% at some point, you can't prevent it from fully charging the battery -- with AlDente you can. And that's why I want Apple to give me the choice -- so I can use AlDente to manage it myself.

Thanks I highly appreciate the detail in the reply. So Al Dente charges the laptop all the way to 60% and then run off the power cord?

 

[acidblood]

Thanks I highly appreciate the detail in the reply. So Al Dente charges the laptop all the way to 60% and then run off the power cord?

Yeah, basically that's what it does. Once it reaches the set amount (60% in your example), it will drain exactly the amount needed from the power adapter to supply the power required by the CPU, GPU, screen, etc. but not any further charging of the battery.

 

[ninjasoforca]

You have no idea what you’re talking about. I, unlike you, do — I’m an electrical engineer, I’ve designed Li-Ion battery-powered products, and I’ve read dozens of actual scientific papers, on peer-reviewed high-impact journals, about battery lifespan.

The Apple feature tries to predict when you’re going to need 100% battery charge, and time the charges that way. To maximize battery lifespan, the main thing it can do is keep it at a lower charge (e.g. 60% seems to be an ideal value) for as long as possible. Batteries degrade much much much faster when near 100% state of charge than when at 60% or even 80%.

I, unlike Apple, actually know when I’m going to need 100% charge. In my case, the answer is: never — OK, maybe once or twice a year, but this year I’ve yet to purposefully charge it beyond 60% (using the AlDente app to control the state of charge).

So, Apple may have the best and brightest engineers of the world. Maybe they can do the very best, state of the art machine-learning mumbo-jumbo (actually, from my experience it’s crap — optimized battery charging doesn’t work for me in the iPhone at all — but let’s pretend for a moment that it’s not crap). Unfortunately one thing that’s beyond Apple is predicting the future: i.e. when will you need 100% charge, so you can start charging it exactly X minutes before so the moment you unplug it, it’s at 100%. Since it can’t do that, those that care enough about managing their battery will always be able to do better. It’s simply impossible to argue with that.

I believe that you do know what you're talking about when it comes to electrical engineering, but you don't seem to know what you're talking about when it comes to Apple features. You are conflating two different battery features:

1. optimzed charging - learns from your use and keeps the charge to 80% until the ML algorithms believe you will need 100%. In my case, my laptop is essentially a desktop and rarely gets unplugged. Thus, MacOS keeps my battery charged to 80% of its maximum charge (more on that below) all of the time. I can manually click "charge to full" if I ever am going to take it out of the wall socket and use it on battery only. I understand that this feature may not work for everyone, but since I almost never unplug my computer, it seems to work correctly for me.

2. Battery health management: This feature actually reduces the full charge capacity of the battery because, just like you say, keeping the battery below 100% helps it age slower. Over time, the OS has dropped the full charge capacity from its factory rating of 7336 mAh to about 5609 mAh, or about 76.5% of its design capacity (per coconut battery). This is a SEPARATE feature from the optimization above, so with optimization also only keeping it charged to 80% of its stated design capacity, we have the battery always plugged in but only charged to about 60% (the same magic number you cited) of its factory design capacity.

In other words, the TWO features, together, do exactly what you say they should be doing

 

[Done Kwotme]

Its not just heat, and not just State of Charge, it is both of these together that stress the battery. Wireless charging is very inefficient, 10% of the power lost at the AC adapter of course but not another 20% of the power goes immediately to heat in this thing we call a core-less transformer (mostly in the wireless charger side, and because all designs are sunny side up, this means the battery gets heated as if its running with a high load) But this is momentary stress that stops when the charging tapers. But once the charging stops, and the phone isn't used, State of charge is not that key of a stress and room temp is optimal for the battery. So even the heuristic "know when you wake and keep delay charging" is kind of useless because aren't using the phone (keeping it hot), and as soon as you are not charging but using the phone, the SOC drops and the momentary stress is gone. Lots of papers on this, lots of data. So if are connected to a charger and not using the phone--no real stress. Even, because once the battery is ~75% full the amount of power from the charger starts to taper to where at 100%, there is almost no power at all and temps slow down on their own. The delay of charging to the last minute or hour theoretically helps, but only a little if you are charging to 100%, probably none at all if you are limiting to 90% charge. And if you are the kind that doesn't mind swapping the battery or the phone every 2 years, you don't have to over allocate the battery capacity this much.

And yes, advances in lithium ion batteries mean more and more capacity---but then whoo-hoo, the battery you are given is limited to 80%. And this is a shame, you were probably better off when you used older cells with less capacity and operated them at 100% charge. Li cells are a tradeoff between structure and capacity---so the lust for more capacity is like building your walls out of 2x2" timbers instead of 2x4" to get more floor space...Advertise a higher capacity and then disable its use. And this is how a Tesla works to get a battery that will live for 8 years, by giving a 90kw battery where the top 30% and the lower 20% of the battery range is disabled, its like putting 400 pounds of dead weight in your car in order to save the world. Another story.

But yes, the disables are about the lawsuits---because a lawsuit is only about a creative lawyer finding a magic ticket to court, biting on the trousers like a small dog with the defendant absolutely certain to not recover their own legal bills while the plaintiff (who isn't a real customer with a complaint, they are basically an employee of the law firm trying to get the class action certified) gets a token and the Company is only trying to minimize the settlement...Yet another story.