You think it's a big step-up from 25W to 45W charging? - You might be wrong!

[Tech Enthusiast]

1 hour ago, HenrySalayne said:

Oh yes you can. And it's trivial. If the 25W charger reaches 25%, the 45W charger has to hit 45% (or at least something close). If this would be the case, we would not have this conversation. As it stands right now, the best case recorded is just one quarter of the advertised improvements. What a joke.

You really need to stop posting this crap.

That is just not how charging works, and it never has and does not work like that for ANY phone or whatever else for that matter.

Just like, 200 horsepower don't accelerate a car twice as fast as 100 horsepower do.

 

Laws of physics are in place that don't match your expectations, but that is a "you" problem, not a Samsung problem.

 

Samsung claims a 50% charge in 30 minutes, and they reach that under best-case conditions, fall short of it by 2-4% on worse conditions. Marketing has always been the best-case kind of thing, and people know that. And the best case recorded also matches their advertised improvements.

 

YOU are the only one that reads 45w charging as "advertised 80% improvement". Neither does Samsung claim that, nor is it possible or sensible.

 

Your example with Ryzen is baffling as well. You compare a CPU that needs to be spot on and every % counts to get a stable FPS in games in real time, ... and compare it to charging that is usually done HOURS before you wake up. OF COURSE, people care more for the former and can't be bothered to get all upset about the latter.

[HenrySalayne]

1 hour ago, Tech Enthusiast said:

You really need to stop posting this crap.

That is just not how charging works, and it never has and does not work like that for ANY phone or whatever else for that matter.

Just like, 200 horsepower don't accelerate a car twice as fast as 100 horsepower do.

Wow. I think you should spend some time filling the gaps in your scientific knowledge. The energy of a moving body follows the quadratic equation E = 1/2 * m * v². So you need four times the power to get to the same speed two times as fast.

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

 

1 hour ago, Tech Enthusiast said:

Laws of physics are in place that don't match your expectations, but that is a "you" problem, not a Samsung problem.

So energy conservation is a lie? Oof...

 

1 hour ago, Tech Enthusiast said:

YOU are the only one that reads 45w charging as "advertised 80% improvement". Neither does Samsung claim that, nor is it possible or sensible.

Refer to paragraph 1.

 

 

[mr moose]

1 hour ago, HenrySalayne said:

 

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

 

Lithium batteries don't typically charge in a linear fashion.   The most linear stage you could argue would be the CC stage of a cell charge from 0v to anything from 2.5V to 3.2V.  Keeping in mind most cells aren't fully charged until 4V+.  But this is solely dependent on who's measuring, what they are using to do the measuring and which battery they are measuring.   Charge curves can and do  look very different from device to device.   In fact I have seen charge curves that are complete opposites, one a log while the other is an inverse log during the CC stage.   

 

EDIT: I need to add for clarity, that when I say the CC stage is the most arguable as being linear, I mean the actual charge state over time.  The Power being supplied to the cell over this time is anything but linear.

[starsmine]

1 hour ago, HenrySalayne said:

Wow. I think you should spend some time filling the gaps in your scientific knowledge. The energy of a moving body follows the quadratic equation E = 1/2 * m * v². So you need four times the power to get to the same speed two times as fast.

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

 

So energy conservation is a lie? Oof...

 

Refer to paragraph 1.

 

 

Dude, no, the physics of lithium ion, NO battery has ever charged linearly. 
Yes, Energy is power times time, but you can not charge a battery, ANY battery like that. Because of the chemistry, a discharged battery is able to accept more instantaneous power then a 90% charged battery. On top of, the fact its more efficient at lower charge states, as in less of the wattage going in turns into heat. 

Energy conservation isnt a lie, but you are consistently ignoring the rest of the system, where there are losses, and where there are limits. So no, twice the power will not cut the time in half. 

Lets put it in terms of a Power supply for your PC.
this hypothetical Power supply is pulling 100watts from the wall. If it starts to pull 200W from the wall, is it providing double the power to the PC? no.
Things have been lost to heat. and the efficiency curve changed. 
Or just imagine a simple wire, a wire can handle X amount of watts... at temp y. However, at temp y+z, it can now only handle X-t watts. That said, putting in X watts, will heat up the wire, so now the wire can no longer handle X watts.

[HenrySalayne]

10 minutes ago, mr moose said:

Lithium batteries don't typically charge in a linear fashion.   The most linear stage you could argue would be the CC stage of a cell charge from 0v to anything from 2.5V to 3.2V.  Keeping in mind most cells aren't fully charged until 4V+.  But this is solely dependent on who's measuring, what they are using to do the measuring and which battery they are measuring.   Charge curves can and do  look very different from device to device.   In fact I have seen charge curves that are complete opposites, one a log while the other is an inverse log during the CC stage.  

Yes, but that wasn't the point here. The energy stored in the cell is proportional to the integration of the power over time. And there are power limits changing with charge state.

If we charge a battery with 5 W for 1 hour, the battery will be charged to 5 Wh.(ignoring losses). If we charge the same battery (and just assume the battery can take this) with 10W for 1 hour, it will be charged to 10 Wh.

 

And just to get back on topic:

If we charge a phone to 25% with 25W and then in the same timespan to 28% with a different charger, it was effectively charged with 28W. It's seriously that simple. What's actually happening in the background with the battery is interesting but should not be our concern as costumers. Samsung did not write "faster charging with our 45W charger" or even closer to the truth "up to 25% faster charging with our 45W charger", they write "super fast 45W charging" and that's evidently false.

The video in this post shows that it a maximum of 40W for a short time (while the 25W charger managed 29.something W continuously).

 

 

[HenrySalayne]

16 minutes ago, starsmine said:

Dude, no, the physics of lithium ion, NO battery has ever charged linearly. 

Yes, Energy is power times time, but you can not charge a battery, ANY battery like that.

Oh yes you can. Charge it with 1 W, charge it with 2 W, time halved. Yeah, I know there are maximum power constraints changing with charge state but that is not important for the underlying maths. If you can't charge a battery with a set amount of power and you need to lower the power, the time increases. It's seriously not rocket science.

[Gamer Schnitzel]

I returned my 45w charger and ordered the 20w Apple charger. Thanks for posting this. I am glad I won't be ruining my battery!

[LAwLz]

1 hour ago, HenrySalayne said:

Oh yes you can. Charge it with 1 W, charge it with 2 W, time halved. Yeah, I know there are maximum power constraints changing with charge state but that is not important for the underlying maths. If you can't charge a battery with a set amount of power and you need to lower the power, the time increases. It's seriously not rocket science.

That's not really how chargers for phones work though. They dynamically adjust how much power gets sent depending on the battery. The wattage you see advertised on the chargers is just the maximum allowed, not the average wattage that you will get.

 

A 45 watt charger will not constantly provide the phone with 45 watts. That would be madness. It would completely ruin the battery. This is not exclusive to Samsung either. It goes for everyone that does fast charging.

 

 

As for the whole "Samsung's 45 watt charger only provides a maximum of 40 watts", that might be because the charger is rated for 45 watts of AC current. With a ~90% efficienct that 45 watts turns into 40 watts at the port, which is where Phone Arena were measuring.

[Tech Enthusiast]

3 hours ago, HenrySalayne said:

Wow. I think you should spend some time filling the gaps in your scientific knowledge. The energy of a moving body follows the quadratic equation E = 1/2 * m * v². So you need four times the power to get to the same speed two times as fast.

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

Ah, my bad. So charging is just a matter of energy flow and neither materials on both ends have any impact or losses due to heat, conversion, chemistry or something unimportant like that. Did not know that charging negates those laws.

3 hours ago, HenrySalayne said:

So energy conservation is a lie? Oof...

What do you think heat is?

3 hours ago, HenrySalayne said:

Refer to paragraph 1.

Same.

 

It seems like you are thinking a power line --> charger --> battery is like a bottle --> hole --> cup. Which is simply wrong on about every possible end.

Really should stop trying to argue that against all the people trying to explain why it is wrong. You are just making yourself look bad by googling random snippets from Wikipedia and forgetting to look at all the context (funnily like in that test lol).

[05032-Mendicant-Bias]

I'd rather have a longer battery life than having a powerful 25W or 45W charger that tax the battery.

 

I bought a phone whose battery lasts two weeks and I use a 5W charger that takes half a day to preserve battery life, I can't stand charging devices every night or multiple times a day.

 

 

[05032-Mendicant-Bias]

3 hours ago, HenrySalayne said:

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

This very simple model isn't even accurate for capacitors. When you double the current, you increase the ESR losses and need more than half the time to charge the capacitor. How much more depends on how much power is wasted by the ESR.

Batteries are electrochemical devices with complex internal states (like temperature, how dendrites formed on the electrodes, how is the electrolye faring, etc...). charging is non linear. Even the statement "Increasing power will reduce charge time" might not be valid depending on the battery state.

[HenrySalayne]

1 hour ago, Tech Enthusiast said:

Really should stop trying to argue that against all the people trying to explain why it is wrong. You are just making yourself look bad by googling random snippets from Wikipedia and forgetting to look at all the context (funnily like in that test lol).

Hilarious. Spreading wild theories to make yourself feel better and to undermine the credibility of your opponent after making a fool out of yourself. A classic move and quite popular in recent times.

Maybe we can once again take a step back from the kindergarden level and return to a more factual discussion.

 

1 hour ago, Tech Enthusiast said:

Ah, my bad. So charging is just a matter of energy flow and neither materials on both ends have any impact or losses due to heat, conversion, chemistry or something unimportant like that. Did not know that charging negates those laws.

I assume you still haven't crunched some numbers? Because if you did, you should be outraged about the incompetence of the engineers working at Samsung. You bought a 45W charger and more than 75% of this additional juice is turned into heat? Outrages!

Nice try but I highly doubt the level of efficiency is this abysmally bad. But maybe I'm wrong and the culprit is not in the marketing department but from engineering.

 

1 hour ago, 05032-Mendicant-Bias said:

This very simple model isn't even accurate for capacitors.

It's a model. Like every other model it has it's inaccuracy but it still shows the fundamental underlying principles. I don't know why nobody is complaining about E = 1/2 *m * v². That's just another model with it's own inaccuracies.

But I think we can agree on one thing: losses cannot explain why adding 20W results in less than 5W of additional, effective charging power.

[Tech Enthusiast]

Just now, HenrySalayne said:

Maybe we can once again take a step back from the kindergarden level and return to a more factual discussion.

Sure, if you start presenting facts and not just wild fever dreams for once. Like really... your nonsense has been debunked time and time again. There are quite a few people in this topic alone that really know how batteries and charging works (much better than me), and you just insist on ignoring all they say, while keeping your happy wonderland ideas intact and repeated over and over.

[wanderingfool2]

6 hours ago, HenrySalayne said:

Wow. I think you should spend some time filling the gaps in your scientific knowledge. The energy of a moving body follows the quadratic equation E = 1/2 * m * v². So you need four times the power to get to the same speed two times as fast.

Charging on the other hand is a linear equation. It's simply E = P * t. So twice the power will cut the time in half.

Honestly, stop posting this nonsense; thinking you know the answer when you clearly are just throwing around equations with the concept you know how they apply in this situation when you obviously have zero clue how charging batteries work.

 

If you don't believe me; look at the 3:55 mark in this video

Summary:

5w -  2h41m

10w - 1hr57m

20w - 1hr34m

 

Based on your super flawed logic of a linear one based of 5w charging as a baseline:

5w - 2h41m

10w - 1h 20m (37 min off actual)

20w - 40 min (54 min off actual)

 

So please just let this topic stop and stop trying to claim that it's false advertising because you're to set in your ways to properly recognize that it's not really false advertising.  If you are going on about that, then you need to go on about Apple and their 30w fast charger claims.  The fact is it charged faster than Apple and Pixel to the 50% mark (beat both by 10 min).  Even comparing the 25w to 45w the 50% mark is on the order of minutes not seconds.

 

The whole issue I also have is that other outlets are already starting to pick up the GSMArena and running with the numbers and starting to form a false conclusion (and then like you sticking to that conclusion)

 

[HenrySalayne]

26 minutes ago, Tech Enthusiast said:

Sure, if you start presenting facts and not just wild fever dreams for once. Like really... your nonsense has been debunked time and time again. There are quite a few people in this topic alone that really know how batteries and charging works (much better than me), and you just insist on ignoring all they say, while keeping your happy wonderland ideas intact and repeated over and over.

You want facts: there is no 45W charging. Every theory so far could not at least explain the differences between Samsung's 25W and 45W charging. So I would kindly ask that you crunch some numbers before claiming "45W charging is legit".

And here is another free fact for you!

Results by phonearena:

Mean power (to 100% with 45W charger: 17.9 W

Mean power (to 100%) with 25W charger: 15.9 W

And for GSMArena:

Mean power (to 100%) with 45W charger: 18.8 W

Mean power (to 100%) with 25W charger: 17.3 W

 

And who am I ignoring? I'm pretty sure I covered almost every response.

 

In an surprising turn of events, the title is still accurate. You think it's a big step from 25W charging to 45W charging? - You might be wrong!

 

[HenrySalayne]

51 minutes ago, wanderingfool2 said:

If you are going on about that, then you need to go on about Apple and their 30w fast charger claims.  The fact is it charged faster than Apple and Pixel to the 50% mark (beat both by 10 min).

I love learning new things. Quite recently I learned this is called "fallacy of relative privation" (pointing at other things that are considered much worse).

 

53 minutes ago, wanderingfool2 said:

So please just let this topic stop and stop trying to claim that it's false advertising because you're to set in your ways to properly recognize that it's not really false advertising.

So the average consumer takes a look at the S22 and the S22 Ultra. There are four key features listed for the latter, one of which is "super fast 45W charging". The S22 on the other hand is only capable of 25W charging. And this consumer must be totally out of their mind to assume this is a noticeable difference. They even published two values, one of which is 80% higher. It's completely unreasonable to assume one of these two phones would charge quite a lot faster.

But if all the tests show that in a best case (one outlier) it's not even 25% faster, this is not considered false advertising, because? I don't know how anybody could drew this conclusion.

 

59 minutes ago, wanderingfool2 said:

The whole issue I also have is that other outlets are already starting to pick up the GSMArena and running with the numbers and starting to form a false conclusion (and then like you sticking to that conclusion)

Oh, GSMArena? Wasn't that the test with the overall best results for the 45W charger. They must have messed up badly!

Keep it going, I can't stop laughing. It's good to have some quality entertainment with all this stuff going on in the world.

[Curufinwe_wins]

Without the stupid shade being thrown around here (the analogy to car horsepower is actually extremely apt, on many levels. and the current fleet of EVs have the exact same issue btw)... I do legitimately wonder if the disappointing gains from the higher power charger (which lets be blunt, no one should use regardless of the situation, higher charging rates damage batteries faster and we are way past diminishing returns with current battery sizes)... have to do with relatively tight thermal management of the device already. Similar to performance throttling from skin temperature, it is quite common for imperfect positioning on wireless chargers to lead to excess heat and massive speed losses. Likewise, it is plausible that under normal idle workloads the device simply cannot sustain charging thermally significantly above 20W.

 

One relatively easy way to test this would be to do an icewater bath charging test, similar to the macbook air tests LTT did years ago now demonstrating how to boost sustained perf by increasing cooling.

-------------

Example of the situation in cars. Both of these vehicles 'support 250kW charging'. Neither one comes close to sustaining 250 kW over a charge duration, yet the average power of charging is noticeably better in the beefed up cooling and battery of the Plaid.

 

 

https://www.caranddriver.com/news/a38451158/tesla-model-s-plaid-charging-test-ev-quickest/

 

The second graph here is the reality of charging. Yes though, it is disappointing companies advertise peak instead of average.

[wanderingfool2]

35 minutes ago, HenrySalayne said:

Oh, GSMArena? Wasn't that the test with the overall best results for the 45W charger. They must have messed up badly!

Keep it going, I can't stop laughing. It's good to have some quality entertainment with all this stuff going on in the world.

Are you trying to be trolling or just plain ignorant.  You keep arguing all this non-sense but you can't even realize that the GSMArena, the one you quoted had the most flawed numbers in their testing.  GSMArena was claiming 1% delta for Ultra (It's right there in a big bold graphic on your first post)!  Yet all other sources tell quite a different picture.

 

Anyways, the short of the answer is you are wrong and the fact you think GSMArena, the one you quoted had the best results for 45w says it all.  This is a non-story that was generated from horrible reporting by GSMArena.

[HenrySalayne]

13 minutes ago, Curufinwe_wins said:

The second graph here is exactly what OP seems to be missing/misconstruing about the reality of charging. Yes though, it is disappointing companies advertise peak instead of average.

I'm not missing that point. I try to look at this from the eyes of the average consumer and I'm not evaluating the entire charging process but the differences between Samsung's own 25W and 45W charging. Samsung did a good job with their 25W charging and it's exactly what it should be (they did not just take the peak value but a reasonable average). But 45W - oof, not even close. Neither peak nor average are anywhere near to what you would expect compared to 25W.

And I would not have bat an eye if Samsung did not put their 45W charging claims as one of four key features on their store front. If this is the key selling point of this product, it should be judged accordingly.

 

26 minutes ago, Curufinwe_wins said:

which lets be blunt, no one should use regardless of the situation, higher charging rates damage batteries faster and we are way past diminishing returns with current battery sizes

Exactly.

 

27 minutes ago, Curufinwe_wins said:

I do legitimately wonder if the disappointing gains from the higher power charger have to do with relatively tight thermal management of the device already. Similar to performance throttling from skin temperature, it is quite common for imperfect positioning on wireless chargers to lead to excess heat and massive speed losses. Likewise, it is plausible that under normal idle workloads the device simply cannot sustain charging thermally significantly above 20W.

That is probably one of several reasons. In this test (previously posted by lawlz) the 40W are only a short burst and then it drops even below the 25W charger. But for a consumer it should not make a big difference because I highly doubt they will put their phone on ice to charge. The net benefit is so small, I would question why anyone would spend the extra cash on the 45W charger and even worse - why is it a key feature?

 

 

[HenrySalayne]

9 minutes ago, wanderingfool2 said:

Are you trying to be trolling or just plain ignorant.  You keep arguing all this non-sense but you can't even realize that the GSMArena, the one you quoted had the most flawed numbers in their testing.  GSMArena was claiming 1% delta for Ultra (It's right there in a big bold graphic on your first post)!  Yet all other sources tell quite a different picture.

 

Anyways, the short of the answer is you are wrong and the fact you think GSMArena, the one you quoted had the best results for 45w says it all.  This is a non-story that was generated from horrible reporting by GSMArena.

You don't need to troll to have some fun!

 

And I know these graphs are really confusing and contain a lot of information you have to work through, so I marked the best overall result for you: 

 

As you can clearly see, they beat SamMobile with their 1:03 h and PhoneArena with their 1:02 h. Amazing! How the hell did they pull this off with their incredibly flawed testing? Illegal substances? Should WADA take a closer look at this? I don't know, but they clearly manipulated the numbers!

 

It gets better by the minute!

 

[wanderingfool2]

11 minutes ago, HenrySalayne said:

You don't need to troll to have some fun!

 

And I know these graphs are really confusing and contain a lot of information you have to work through, so I marked the best overall result for you: 

 

As you can clearly see, they beat SamMobile with their 1:03 h and PhoneArena with their 1:02 h. Amazing! How the hell did they pull this off with their incredibly flawed testing? Illegal substances? Should WADA take a closer look at this? I don't know, but they clearly manipulated the numbers!

 

It gets better by the minute!

 

This will be my last post here against you, I don't want to waste my time trying to spoon feed you the answers that clearly you have no intent of actually seeing.  Here's a hint, actually try understanding what people are talking.

 

GSMArena:

1% delta on Ultra at 30 min mark.  Every other outlet that's tried testing it shows 7-9% delta.

 

So yea, they utterly bungled things up, and if they are talking about "tangible" differences, then yea getting the 30 min charge number correct would have been a lot more useful of a state to get correct.  As I've clearly stated from the get go, a real use-case that most people will use it for is that quick 5-10 minute charge.  At which point a difference of 15% faster makes a whole lot of difference.  So yea, GSMArena clearly messed up somewhere in their testing if they found no real difference in % after 30 minutes.  Fact is 15% increase is not a "negligible" difference.

[HenrySalayne]

28 minutes ago, wanderingfool2 said:

This will be my last post here against you,

Sorry to see go. Thanks for the entertainment and farewell old friend! 

 

30 minutes ago, wanderingfool2 said:

GSMArena:

1% delta on Ultra at 30 min mark.  Every other outlet that's tried testing it shows 7-9% delta.

 

So yea, they utterly bungled things up, and if they are talking about "tangible" differences, then yea getting the 30 min charge number correct would have been a lot more useful of a state to get correct.  As I've clearly stated from the get go, a real use-case that most people will use it for is that quick 5-10 minute charge.  At which point a difference of 15% faster makes a whole lot of difference.  So yea, GSMArena clearly messed up somewhere in their testing if they found no real difference in % after 30 minutes.  Fact is 15% increase is not a "negligible" difference.

Ah, the good ol' cherrypicking results. "But they got the best overall result among all other tests!" - "These results don't represent my opinion so they must be flawed and we should ignore them!" But to be fair that was quite surprising. It was only no. 3 on my list of most likely responses.

[HenrySalayne]

@Curufinwe_wins

Sorry to bother you again. Could you give us your opinion on how accurate the charge levels reported by the device are and how much a higher temperature might change these numbers? Could the temperature of the device also influence when it reports "fully charged" (100%)? You seem to have some insights into the matter and your opinion would be much appreciated.

 

[Curufinwe_wins]

11 minutes ago, HenrySalayne said:

@Curufinwe_wins

Sorry to bother you again. Could you give us your opinion on how accurate the charge levels reported by the device are and how much a higher temperature might change these numbers? Could the temperature of the device also influence when it reports "fully charged" (100%)? You seem to have some insights into the matter and your opinion would be much appreciated.

 

It's all fine. 

 

Anyways... charge level accuracy is a big unknown tbh, in that rated capacities and nominal rarely match for a battery, and the level of overprovisioning is not commonly displayed. We tend to presume based on a lack of contrary evidence (unlike in some car evs) that the accuracy is high. Splitting a difference of 1 or 2% at the top end is not really a big consumer issue, and in an ideal world, lion batteries should really only be charged to around 90% anyways.

 

On the previous topic though, one reason I tend not to be super sympathetic towards worrying about wattage ratings and instead only start caring about potentially misleading claims about X times faster or whatever (like a device claiming it can charge in 20 min up to 90% and it actually takes 40min), is actually an older example with phones, particularly with Apple. See for years, after everyone else moved to 11-15+ W chargers apple was still shipping 5W tiny bricks while supporting faster charging. But 11W charging on a phone that is turned on is not 2x faster than 5W. It is more like 3-5x faster (in fact, while screen on, many modern devices don't charge at all on a 5W trickle brick). This is because net charging is naturally the input-consumption. If total consumption is 2W while idling (high but not implausibly so), then a 5W charger is "maxing out" at 3W net and an 11W charger is netting 9W. Up until thermal constraints of course change things.

 

Additionally as a battery gets fuller, two additional factors become relevant. The voltage difference drops, thus providing more back emf and less efficiency (and more heat) and the sensitivity to temperature (in terms of the physical durability of the cells) increases. Both of these combine even beyond the nominal peak skin temperature to cause massive reductions of charging speed above 80% in most smartphones (and cars for that matter).

[HenrySalayne]

13 minutes ago, Curufinwe_wins said:

Anyways... charge level accuracy is a big unknown tbh, in that rated capacities and nominal rarely match for a battery, and the level of overprovisioning is not commonly displayed. We tend to presume based on a lack of contrary evidence (unlike in some car evs) that the accuracy is high. Splitting a difference of 1 or 2% at the top end is not really a big consumer issue, and in an ideal world, lion batteries should really only be charged to around 90% anyways.

Thanks for the input. I still remember from my Note 3 that the battery level indicator jumped up by a few percent when I got from freezing temperatures outside into the heated apartment (which makes sense if it's just measuring the voltage and estimating the battery level)..

That's also what's bothering me about this graph. Why is it getting steeper between 40% and 80%? He says in the video that he only measured a peak power of 40W while the device was below 25% which is quite the contrary to this graph (the flattening at the top is expected).

14 hours ago, LAwLz said:

 

 

I guess temperature differences and variance in battery capacity and quality, and heat dissipation of the device would pretty much explain the deviation of all the charging tests. And it also points towards the conclusion that 25W is pretty close to the design (and thermal) limit of this device (under standard conditions). 

 

 

23 minutes ago, Curufinwe_wins said:

On the previous topic though, one reason I tend not to be super sympathetic towards worrying about wattage ratings and instead only start caring about potentially misleading claims about X times faster or whatever (like a device claiming it can charge in 20 min up to 90% and it actually takes 40min), is actually an older example with phones, particularly with Apple. See for years, after everyone else moved to 11-15+ W chargers apple was still shipping 5W tiny bricks while supporting faster charging. But 11W charging on a phone that is turned on is not 2x faster than 5W. It is more like 3-5x faster (in fact, while screen on, many modern devices don't charge at all on a 5W trickle brick). This is because net charging is naturally the input-consumption. If total consumption is 2W while idling (high but not implausibly so), then a 5W charger is "maxing out" at 3W net and an 11W charger is netting 9W. Up until thermal constraints of course change things.

That's a good point. What would be your expectation for "25W charging now 45W charging!" ? A lot of people said "I would not expect more than a few percent improvement but that's all you need" and from a consumer perspective I would strongly disagree with this statement (personally I also not use 45W charging for the reasons you already explained in your previous post but Samsung seems to think it's a big selling point).