Is there a technical reason that Windows 11 doesn't have built into it battery charge limitation?

[Solid State Soul ( SSS )]

With everything wrong with windows the awenser is obvious, laziness

 

[Bill_Bright]

It is easy to make Windows the scapegoat and blame Microsoft but once again, battery maintenance is a hardware function and laptop makers have made it clear, each maker wants to do it their way. If that were not true, they all would have agreed upon a PC-type ATX Form Factor standard for laptops many years ago. But they refused to even come together to discuss it, and have repeatedly refused many times since.

The result? Laptops are a proprietary mess that cost consumers more.

 

[OkieDan]

Ummm, sorry, but no. That is not so. A simple multimeter can show if a battery is fully discharged (0%) with 0.0V output or fully charged (at 100%), at full voltage AND no longer taking on a charge (increasing in voltage). So they are not arbitrary at all. This does assume when charging, the correct charging voltage, which is always slightly above the battery's rated voltage output, is being applied.

One common phenomenon with all batteries is the closer they get to being fully charged, the slower the charging rate becomes. That is, a 50% discharged battery can rather quickly be charged to 80%, but take longer to go from 80% to 90% and even longer from 90% to 100%. Some say it is similar to trying to go the speed of light. In theory, we can never go that fast because time goes slower and slower the nearer we get to that speed.

This is exactly why, by the way, battery chargers always output voltages a couple volts higher than the battery's rating. A 12V charger will never fully charge a 12V battery. This is why the alternators in our cars typically output ~13.6 - 14.5V.

The issue with keeping a battery plugged in all the time is about allowing it to sit fully charged, day in and day out for weeks or months at a time.

Generally with laptops and with a good battery, it is impossible for it to fully discharge to 0%. This is due in part because the laptop simply cannot run if the voltage drops too low. That is not a safety factor. It just can't run if the voltage drops too low.

The battery can come close to 0% but the chemical reaction does not completely stop. This is how a low battery will slightly recharge itself on the shelf - the chemical process is still going on.

There are exceptions, of course. Super cold can halt the chemical process. A short in the battery can result in constant drain that will eventually take it to 0.0V. Or a short on the output of a battery can fully discharge the battery (like leaving a flashlight on).

He's clearly using % to represent a minimum and maximum Voltage set by battery mfg. Nothing wrong with that.

 

[Wirko]

He's clearly using % to represent a minimum and maximum Voltage set by battery mfg. Nothing wrong with that.

Yes, this. And sorry @Bill_Bright for overlooking your reply. Those "arbitrary limits" aren't completely arbitrary. However, a notebook manufacturer can calibrate the charge indicator to show zero (and turn off power) at 2.9 volts, or maybe at 2.8 volts. The latter would give the user a slightly longer run time and probably a slightly shorter battery life. And I'm oversimplifying everything anyway, as we know that the voltage alone is a poor measure of the state of charge (also because you can't measure no-load voltage when the notebook is running).

It is easy to make Windows the scapegoat and blame Microsoft but once again, battery maintenance is a hardware function and laptop makers have made it clear, each maker wants to do it their way. If that were not true, they all would have agreed upon a PC-type ATX Form Factor standard for laptops many years ago. But they refused to even come together to discuss it, and have repeatedly refused many times since.

The result? Laptops are a proprietary mess that cost consumers more.

It's not wrong to blame Microsoft, either. Or rather Microsoft+Intel+AMD. They aren't powerless against HP+Lenovo+Dell when it comes to setting standards. If Intel said, hey everyone, we want a small bit of control over battery charging via our API, or else you're not getting that shiny "Evo" sticker, everyone would listen and obey.

Microsoft could also market this feature as an example of how great "AI" is. It could vacuum up all the available information and determine whether you'll be sitting in your office all day (charge to 75%) or out in the field all day, or flying for more than x hours (charge to 100%).

 

[Bill_Bright]

He's clearly using % to represent a minimum and maximum Voltage set by battery mfg. Nothing wrong with that.

Huh? Did you note and understand what I was replying to? Sorry but it doesn't appear you did. Or perhaps the definition of the word, "arbitrary" is not fully appreciated.

I never said representing charge levels as a percentage was wrong. I said 0% and 100% are not "arbitrary" limits set by the maker.

Definition of arbitrary: Determined by chance, whim, or impulse, and not by necessity, reason, or principle.

It appears there is a general misunderstanding of how batteries work and how their charge levels are determined. Depending on the battery chemistry, a battery is generally considered "dead" (in need of replacing - or charging if rechargeable and still good) when it can no longer power the device it is intended to power. This varies greatly by the device, but it is generally to be when its voltage drops below ~75% of its rated value. Again that varies greatly so depending on the battery (and load), that could be as high as 90% or as low as 50%.

Take, for example, a 12VDC car battery. Note a brand new, fully charged car battery should be somewhere between 12.2 and 12.6V when the engine is not running. If it reads 11VDC, that battery is not good and may struggle to start the car. If it drops below 10VDC, you probably will just hear a click (if lucky) when you turn the key. And of course, the load matters. A tiny 4-cylindar engine is much easier to turn over than a big 8-cylindar - and why bigger engines come with higher capacity batteries.

As Wirko correctly notes, 0% charge does NOT mean 0.0V. So, for the record, the voltages at 0% charge will be much higher than 0V on a typical laptop battery since these days, the most common voltage used with laptops is ~19VDC.

Those "arbitrary limits" aren't completely arbitrary. However, a notebook manufacturer can calibrate the charge indicator to show zero (and turn off power) at 2.9 volts, or maybe at 2.8 volts. The latter would give the user a slightly longer run time and probably a slightly shorter battery life.

Right, they are not arbitrary. Thanks for that.

Note a .1V difference between 2.9V and 2.8V (for sure, those are arbitrary numbers you picked) is insignificant. And the runtimes and battery life differences are incalculable. To illustrate, let's use something a little more realistic and assume ~75% charge. Then, using your demonstration and a typical 19V laptop battery, we are looking at 14.25V and 14.35V. That difference is still insignificant and incalculable.

Why?

"IF" a computer presented a constant load on the power supply (in this case, the battery), then, maybe, I repeat, maybe the runtime differences could be determined. But the power demands created by the various components (CPU, GPU, RAM, drives, the display screen, etc.) are constantly changing (1000s or millions of times every second), and therefore, so is the load (and drain) on the battery. I note even the battery's and the ambient (room) temperatures can impact runtimes.

In other words, with a computer there are way too many naturally occurring variables affecting the discharge rate to create a constant, and therefore measurable discharge rate. A computer is nothing like a flashlight or wristwatch that creates a consistent load on its battery.

There is no evidence such a minor difference will extend or decrease the life expectancy of a battery. Other than bouncing a battery off the floor, the typical influences on battery life expectancy of rechargeable batteries are (1) heat - specifically, excessive heat. Cold, even extreme cold generally does not cause permanent damage to a battery UNLESS its case cracks due to the cold. Extreme cold may cause the chemical reaction to slow considerably or even cease. But once temperatures return to normal, the battery typically will too.

(2) Shorting the output. Ohm's Law (I = V/R) says when resistance (R) drops and the voltage(V) remains the same, current(I) MUST go up. Excessive current increases heat. See (1).

(3) A battery can, in rare circumstances "reverse polarity" if it ever reaches 0V. But that is very very rare.

(4) This is controversial and depends on battery chemistry. There are claims that Li-Ion battery life will decrease if they are kept 100% charged 24/7 for weeks and weeks on end.

(5) The number of charge/discharge cycles.

(6) How deep the discharges regularly are.

(7) The normal passage of time.

Note: There are other factors, but those are the main ones I can think right now. And for sure, those factors vary by battery chemistry (Li-Ion, SLA, NiMH, NiCd, etc.).

Clear as mud, right?

 

[ty_ger]

There is no scientific evidence, nor a technical reason that a battery would feel better if it's half empty.

Come on! How can you say that with a straight face? It's chemistry! The scientific evidence is abundant. Fully charged and fully discharged are the two most unstable conditions for a lithium ion/polymer/whatever battery. Everybody knows not to charge them too fast, not to discharge them too fast, and do not leave them long-term in a more unstable state when a more stable state is available; otherwise service life is negatively affected. The way that the battery becomes damaged and why it behaves its way is fascinating.

 

[Bill_Bright]

Everybody knows not to charge them too fast

Huh? Sorry, but nobody knows that because that is not true, or how battery charging even works. Batteries dictate how fast they charge - depending on the maximum capability of the charger.

Chargers do not "push" the charging voltage. That is, they don't cram it down the battery's throat. Instead, the battery will demand and take what it is capable of taking on. A battery will not take on more than it can handle - even with a monster charger.

This is how you can use the battery or the alternator's voltage from one vehicle to jumpstart and charge the depleted battery of another vehicle - all without hurting the battery. Or, you can use a tiny "trickle" charger to charge that depleted battery. The difference is it will take hours instead of minutes.

The danger for allowing a battery to take on a charge "too" fast is heat, not the voltage or charging rate itself. So don't lay a blanket over the laptop, or have the laptop in the sun when charging! If still worried, with the laptop in the shade, flip it upside down and remove the battery cover to allow heat to escape while charging from a near discharge state.

not to discharge them too fast

Again, not true or even possible in normal use - that is, ASSUMING the load on that battery is a proper load and not faulty. If the battery was designed to support that laptop and is in good condition, and that laptop is not otherwise damaged such that it presents a faulty load (like a short) on the battery, then it would be impossible to discharge it too fast.

Fully charged and fully discharged are the two most unstable conditions for a lithium ion/polymer/whatever battery.

Unstable? I understand what you are getting at, but "unstable" is not the right word. Neither condition suggests or creates an "unstable" condition. Nor does either condition hurt the battery AS LONG AS it does not remain in that state for extended periods of time - as in weeks on end. In fact, most batteries benefit from occasional deep discharge/full charge cycling.

I mean what good is a laptop to a road warrior if he or she cannot use it for its full runtime, or use it in battery mode beyond 50% charge?

The scientific evidence is abundant.

No it isn't. ARF is right. There is no scientific evidence to suggest a battery will feel better at 50% charge. There is some evidence suggesting long term storage at either of the "extreme" states may shorten the lifespan. But again, the point there is about the battery remaining at that extreme state, unused, for weeks on end.

Again, it is all about extended (weeks and weeks) periods in one of those extreme (fully charged or fully discharged) states. And, the battery chemistry matters too. Some batteries could care less the charge rate when stored.

 

[ty_ger]

what?!

You guys are off in left field somewhere. lol

It's not worth my time.



I think you are making a lot of assumptions about built in protection and charge controllers. True, with proper protection and charge controllers, you can't over-charge them, over-discharge them, or use them or recharge them too fast. Conversely, for faster advertised charge times, higher power output, or longer advertised battery life, compromises may be made in the controllers which definitely will affect battery life.

Take a Li-Ion battery and do what you want with it, with no controller or protection, and you definitely can ruin it within minutes, hours, days, months, or years. Based on how you treat it, it will respond.

I assume the OP is asking about enabling more conservative limits on a controller which is not conservative-enough for their liking.

No it isn't. ARF is right. There is no scientific evidence to suggest a battery will feel better at 50% charge.

Absolutely false. Well, more like 80%, but whatever.

Don't anthropomorphise its "feelings", instead study its chemistry. Charge state absolutely affects rate or deterioration of the plates and/or separating layer. Not just storage, but use. There is no real difference between long-term storage and "use" when the battery is always full. They are effectively the same thing.

 

[ZAPD0S2009]

When plugged in the laptop does not take current from the battery. It takes power from the charger in A/C mode. Download some simple lightweight software like BatteryBar and it will show you your cycles, and degradation. It will also show how the laptop will be running on A/C, which is almost similar to technically "disconnecting" the battery.
edit - grammar

 

[Bill_Bright]

Absolutely false. Well, more like 80%, but whatever.

Totally true. Sorry but it is you out in left field and it is you making assumptions.

LONG TERM STORAGE​

​

EXTENDED PERIODS​

​

EXTREME STATES (fully discharged, fully charged)​

​

ABUSE​

Those are the conditions where these issues may be a factor.

Take a Li-Ion battery and do what you want with it, with no controller or protection, and you definitely can ruin it

What a silly statement. Now you are saying misusing, abusing or not using the battery as intended will be detrimental to the battery. Well, no sh!t Sherlock!

It's not worth my time.

And then you kept going.

Well, I'm not. Have a good day.

 

[ty_ger]

What a silly statement. Now you are saying misusing, abusing or not using the battery as intended will be detrimental to the battery. Well, no sh!t Sherlock!

Then you recognize that there is a spectrum. What do you think happens if you charge a battery more or less? Or discharge it more or less? Or charge or discharge it faster or slower? The result on long-term serviceability is affected. It isn't black and white. And companies (Tesla for example, or any number of phone or laptop manufacturers) push the limits of batteries for various sales reasons, and longevity is affected. Without doubt it is affected. Proven. Their are valid situations where a charge limit would be beneficial. Some products more than others; as explained.

Research it.

Or live in a fantasy world where batteries have feelings, and the only possible feelings are binary happiness or sadness.


You agree on the long-term thing. Long-term storage is not use. Neither is leaving the battery fully charged the whole time. Now, consider why your concerns in one case remain in the other case.

"100%" is an arbitrary value. It is not defined. The higher the manufacturer pushes its "100%" value for operating-time advertising reasons, the worse it is to remain in that range long-term.

 

[ARF]

The scientific evidence is abundant. Fully charged and fully discharged are the two most unstable conditions for a lithium ion/polymer/whatever battery.

Can you post at least one link, so everyone of us could read it?

Fully charged means that the voltage reaches 100% in a certain voltage range, say 3.2 volts to 4.2 volts.

I don't think the lithium "feels" worse if its state is at 3.5V than if it were at 4.19V.

 

[ty_ger]

Fully charged means that the voltage reaches 100% in a certain voltage range, say 3.2 volts to 4.2 volts.

Don't you wish it were that simple? If it were so simple, you wouldn't have to say "say".

This is a big topic, if you dig in. Surface level seems simple, but digging in, it gets complex. If you assume that everyone chooses safe practices, with the best equipment, with best battery longevity, you have a much different outcome than reality.

Critical thinking time. Why does the military/aviation/critical systems use a lower "100%" voltage threshold than standard consumer electronics? Continuing on, do you still think that leaving a standard consumer battery fully charged is not detrimental?

 

[OkieDan]

Huh? Did you note and understand what I was replying to? Sorry but it doesn't appear you did. Or perhaps the definition of the word, "arbitrary" is not fully appreciated.

I never said representing charge levels as a percentage was wrong. I said 0% and 100% are not "arbitrary" limits set by the maker.

Definition of arbitrary: Determined by chance, whim, or impulse, and not by necessity, reason, or principle.

It appears there is a general misunderstanding of how batteries work and how their charge levels are determined. Depending on the battery chemistry, a battery is generally considered "dead" (in need of replacing - or charging if rechargeable and still good) when it can no longer power the device it is intended to power. This varies greatly by the device, but it is generally to be when its voltage drops below ~75% of its rated value. Again that varies greatly so depending on the battery (and load), that could be as high as 90% or as low as 50%.

Take, for example, a 12VDC car battery. Note a brand new, fully charged car battery should be somewhere between 12.2 and 12.6V when the engine is not running. If it reads 11VDC, that battery is not good and may struggle to start the car. If it drops below 10VDC, you probably will just hear a click (if lucky) when you turn the key. And of course, the load matters. A tiny 4-cylindar engine is much easier to turn over than a big 8-cylindar - and why bigger engines come with higher capacity batteries.

As Wirko correctly notes, 0% charge does NOT mean 0.0V. So, for the record, the voltages at 0% charge will be much higher than 0V on a typical laptop battery since these days, the most common voltage used with laptops is ~19VDC.


Right, they are not arbitrary. Thanks for that.

Note a .1V difference between 2.9V and 2.8V (for sure, those are arbitrary numbers you picked) is insignificant. And the runtimes and battery life differences are incalculable. To illustrate, let's use something a little more realistic and assume ~75% charge. Then, using your demonstration and a typical 19V laptop battery, we are looking at 14.25V and 14.35V. That difference is still insignificant and incalculable.

Why?

"IF" a computer presented a constant load on the power supply (in this case, the battery), then, maybe, I repeat, maybe the runtime differences could be determined. But the power demands created by the various components (CPU, GPU, RAM, drives, the display screen, etc.) are constantly changing (1000s or millions of times every second), and therefore, so is the load (and drain) on the battery. I note even the battery's and the ambient (room) temperatures can impact runtimes.

In other words, with a computer there are way too many naturally occurring variables affecting the discharge rate to create a constant, and therefore measurable discharge rate. A computer is nothing like a flashlight or wristwatch that creates a consistent load on its battery.

There is no evidence such a minor difference will extend or decrease the life expectancy of a battery. Other than bouncing a battery off the floor, the typical influences on battery life expectancy of rechargeable batteries are (1) heat - specifically, excessive heat. Cold, even extreme cold generally does not cause permanent damage to a battery UNLESS its case cracks due to the cold. Extreme cold may cause the chemical reaction to slow considerably or even cease. But once temperatures return to normal, the battery typically will too.

(2) Shorting the output. Ohm's Law (I = V/R) says when resistance (R) drops and the voltage(V) remains the same, current(I) MUST go up. Excessive current increases heat. See (1).

(3) A battery can, in rare circumstances "reverse polarity" if it ever reaches 0V. But that is very very rare.

(4) This is controversial and depends on battery chemistry. There are claims that Li-Ion battery life will decrease if they are kept 100% charged 24/7 for weeks and weeks on end.

(5) The number of charge/discharge cycles.

(6) How deep the discharges regularly are.

(7) The normal passage of time.

Note: There are other factors, but those are the main ones I can think right now. And for sure, those factors vary by battery chemistry (Li-Ion, SLA, NiMH, NiCd, etc.).

Clear as mud, right?

I clearly understood what he meant, he confirmed as much in his reply to me. The arbitrary "0%" he referred to is the arbitrary "~75%" you referred to. When he said 0% it was clear to me he was referring to the amount of charge a device would report is remaining, which we can presume device mfgs base partially on battery mfg specs, which are based on battery chemistry. If you took just a little bit of time to understand what other people are referring to, you would have understood this as well.

 

[Bill_Bright]

The arbitrary "0%" he referred to is the arbitrary "~75%" you referred to.

No it isn't.

I am sorry but you once again have shown us you do not understand the definition of the word "arbitrary". I did not come to that ~75% value "by chance, on a whim, or impulse". I used my friend Bing DDG Google to verify my "facts" before posting. What a concept, huh?

"If you took just a little bit of time to" do a tiny bit of research yourself with your preferred search engine, you would have seen it is not arbitrary at all, but an approximation (hence the "~") of the consensus noted among several authorities on battery behavior and battery chemistry.

I clearly understood what he meant, he confirmed as much in his reply to me.

Then you ignored his next reply!

"If you took just a little bit of time to" read through the thread "and understand what people" are saying and "referring too", you would have seen where, in his very next post, post #29, @Wirko clarified his comment and acknowledged that the manufacturers did not come to that 0% representative value arbitrarily either. He went on to correctly point out that manufactures set and "calibrate" their monitor circuits to a predetermined (not arbitrarily picked) value.

Wirko and I are on the same page with the facts. You are not.

***

This thread is about Windows 11 support for (or lack thereof) battery management. And to that, I refer back to the OP's topic and the following comments in his first post,

My phone I have limited to 85% as Samsung understands this and offers that in settings.

So, I was wondering why does Microsoft not have this feature

Yes! "Samsung" understands that and it is important to point out that Samsung is the "hardware" manufacturer of the phone. The "operating system" used on Samsung phones is developed by Android and NOT Samsung.

So why expect Microsoft, the "operating system" developer used on those laptops, to have this feature and not the "hardware" manufacturers of the laptops?

As @cvaldes and other have correctly noted, this is the hardware makers responsibility. And as he later, correctly IMO, points out, people want more battery life (runtime). So manufacturers have purposefully (not arbitrarily) set the monitoring circuits to allow the battery to run down to near zero charge.

It must also be understood they cannot allow the battery to actually reach 0% charge. If that were to happen, the battery would not even have enough power remaining to power the laptop so it could put itself into hibernation mode. The laptop would simply crash and that is never good for any computer.

As far as capping the charge to some value less than 100%, again, as cvaldes points out, people want maximum runtime. Thus, it is up to the "hardware" maker to provide the option to limit that, if they choose to.

 

[ty_ger]

"If you took just a little bit of time to" read through the thread "and understand what people" are saying and "referring too", you would have seen where, in his very next post, post #29, @Wirko clarified his comment and acknowledged that the manufacturers did not come to that 0% representative value arbitrarily either. He went on to correctly point out that manufactures set and "calibrate" their monitor circuits to a predetermined (not arbitrarily picked) value.

They start out as arbitrary. Once chosen they are no longer arbitrary. But why one value is chosen versus another does often seem arbitrary. We are not in their meetings. All we can do is say 'oof, that was a pretty poorly chosen value' 2 years later when a strong trend forms for a laptop model to have puffed-up batteries breaking keyboards and track pads or needing battery replacements regularly at a certain age.

There is no standard voltage value for specific percentages. It does seem very arbitrary. It is not defined.

 

[Bill_Bright]

They start out as arbitrary. Once chosen they are no longer arbitrary.

That makes no sense at all.

"Chosen"??? How? Eenie meenie miney moe? Darts on the wall?

Certainly not, according to you, by any logical method base on measurable, empirical data for that would not be arbitrary then, now would it? Wow!

We are not in their meetings.

Right! And yet you just claimed to know how they start out and supposedly when they no longer are arbitrary.

There is no standard voltage value for specific percentages.

Of course not! Why would there be? Math is math. If a fully charged battery normally reads12V but now reads 10V, guess what? It is 83.3% charged. How do I know. Math! If it drops to 9V, it is now 75% charged. If 6V, 50%. See how that works? It is not rocket science. It is 5th or maybe 6th grade math.

Now of course runtime remaining will be different because every computer becomes a unique computer within the first few minutes after the very first boot by the end-user. And because every user uses their computers in unique ways, performing a wide variety of tasks that place a wide variety and ever -changing loads and demands on the battery.

Therefore, runtimes are always estimated. Not exact, nor arbitrary either.

It does seem very arbitrary.

"Seem"?? Ah! Now I get it. If ty_ger doesn't understand how the manufacturer came up with a value, they must have just pulled a number arbitrarily out of a hat. Got it.

No more.

This thread is about Windows battery management support, or the lack of it.

 

[ty_ger]

I think you don't read.

There is no 'x.xx volt is defined as full'. That value doesn't exist. Same for empty. The manufacturer can choose whatever value they want. Some are more harmful than others. But they will be aggressive or tame for various reasons. Aggressive for higher reported performance capabilities or longer reported battery on-time or just due to poor/cheap circuit design, or tamer for longer battery longevity or for a product with a longer warranty period which doesn't use a lot of power. Thusly, longevity is affected by the manufacturer's decision. And how long the consumer chooses to remain at undesirable levels available to them (leaving it always charged, for example), affects the battery longevity.


Read.

Repeat. Repeat. Repeat.


This isn't a fantasy world which exists without compromises.


This was a thread about the idea of allowing consumers to choose limits, and whether it would be feasible. It then devolved into nonsense about a battery's emotions, about a fantasy idealistic world where no compromises exist, and a fantasy world where the only battery damage which occurs happens due to intentional abuse.

It would be better if we argued to the OP that it is unfeasible, rather than argue that battery degradation is impossible and the OP is dumb.