TL;DW: Fast charging over 2 years only degraded the battery an extra 0.5%, even on extremely fast charging Android phones using 120W.
And with that, hopefully we can put this argument to rest.
However the Battery Saver mode on Androids that only charges the battery up to 80% DOES extend battery life. Substantial evidence shows that a high State of Charge accelerates degradation through: solid electrolyte interphase growth, loss of lithium inventory, and loss of active materials. (See: mdpi.com)
Here’s a fun fact: phone manufacturers know this. So what they call “100%” is not actually 100%. Your phone will not charge your battery to full. Battery charging is already designed around this.
Got proof? I’ve not cracked open a phone for a while to see if the component labelling matches the interface, let alone tested capacity of an extracted battery directly.
He’s not talking about 80/20 limits. he’s talking about material breakdown at extremes. Not all manufacturers spec in 80/20 limits. AFAIK, only Samsung actually lets you stop it completely at 80, the rest just try to let it sit no higher than 80 all night.
If they were saccrificing 40% of runtime to keep you from having to replace your battery, that would 100% be in the sales pitch.
And honestly, that article isn’t a great source of truth. A number of the statements in there are inaccurate or, at the very least, misleading.
Charging beyond 100% or below 0% is mostly BS. The proper max voltage of the battery is a physics thing, they are in equilibrium at 4.7 / cell. Picking at a low power limit is up to the manufacturer and their choice in power distribution circuitry. He asked the chemist if you could overcharge or overdischarge a battery and mistook that as an answer that it was feasible to overcharge/overdischarge them.
“Leaving a charger plugged in at the wall and turned on wastes energy False (well, maybe a tiny bit)” This is still true for many chargers, and calling it out as a little bit in his own arbitrary numbers is disingenuous.
“Batteries perform worse when they’re cold False (mostly)”
Rest assured, your C rating is wildly affected by temperature; he’s trying to again call it out as slight, which is making his own narrative.
“Powering off a device occasionally helps preserve battery life False”
The whole time your phone is on, you are charging or discharging. Those cycles wear on the battery any time you shut your phone off, you are in the least damaging mode for your battery, especially if it’s around 50% or so.
“Using an unofficial charger damages your phone True”
100% BS, using a crappy charger might damage your phone. Buying a quality 3rd party chager is no problem at all.
The author doesn’t appear to have a strong electronics background and he didn’t ask the right questions or fully understand the importat parts of the answers
“And if too much current is delivered to a battery, that could mean ripping out too many of those lithium ions and leading to the same kind of degradation you read about earlier. That’s not to say that all off-brand chargers will be this bad, Griffith notes, but you’re still probably better off sticking with an official model.” is not the same as “Using an unofficial charger damages your phone”
Article rests on one expert. That assistant professor’s publication list doesn’t seem to contain evidence about it, plus the quotes in the article don’t directly say it happens.
Maybe it does, but that article only seems to be guessing based on (admittedly reasonable) theory.
Iirc the reason Samsung phones were exploding a few years back is because they fucked up the settings for battery management.
That depends on the manufacturer, some do, some don’t. My phone has a setting to control the max charge, so I set it to 80% when I got it.
Yes, but that 100% is not really that. It has been programmed to display that percentage, when i reality its 80%.
No, I’m saying that not all manufacturers have that limit, and it’s a relatively new setting (last few years). If you have an older phone or something not from the top few manufacturers, it might not have that feature.
This is like spinal tap. Yeah but my phone charges to 110%. I don’t think you understood what they’re trying to say. Changing what 100% means isn’t a setting or “relatively new”
I’m saying when your phone charges to 100%, some manufacturers take that to mean 80% of capacity, whereas others actually charge the battery to 100% of capacity.
Exactly, which is neither a user setting or relatively new. Battery manufacturers have always had to decide what voltage is what state of charge (percent).
The user setting where you limit it to 80% is on top of what the previous commenter was describing
No, they’re saying that some hardware manufacturers report 80% as 100% (as you noted) while others do not. Just like some manufacturers report 5% as 5% while others report 10% as 5% with the realization that most people misjudge when they’ll be able to charge.
Source?
I always find the same study referenced, which was good science but also almost 30 years old. I wonder if this is still true for modern batteries?
Correct me if I’m wrong, but as far as I know there haven’t been significant changes in Li-Ion and LiPo batteries aside from extra density - which would only increase the effect. But it seems like solid-state batteries are starting to hit the real world now
I bet thats wrong, but I know ….
There’ve been usage changes
- iPhone has “Optimized Charging” where it predicts usage and tries to keep about 80% charge until it expects you to use it
- iPhone has “Adaptive Performance “. Maybe not charging but tries to gradually ramp to “low power mode” to be gentler on the battery
- all phones likely have refined charging curves to match battery technology
It is, but phone manufacturers know this and already programmed their charging circuits to take it into account.
But if you’re using 18650 cells or some other lithium based battery for other purposes (vapes for example), it’s something to keep in mind.
FYI: During this test it saved about 5% of SoH.
It must help as my dad’s S23 (which I happen to use now) has about 88% battery life with 870 cycle counts (he always charged to 80% with said option), and for that I am grateful.
“And with that, hopefully we can put this argument to rest.”
That’s not how the internet works, but nice try though ;-)
I disagree!
You fool! You fell into the classic blunder! All this time it was I, Dio!
You guys joke and all, but fast charge induces bigger heat and then translates in more harm for the batteries (which will affect more in hot places).
If we want to close this discussion forever I think all the anxiety that comes from this subject at all is due to the fact we can’t easily replace the batteries, if we could (with the normal-ish battery sizes we have today), I don’t think this test would be even worth doing.
While that seems obvious, I’ll disagree
- phones have a charging curve that takes into account heat, battery level and probably more factors specific to battery health. Most of the additional charging speed is likely minimal effect
- You can have a battery replaced on even the latest iPhone for $99 or less, and I expect most phones to be cheaper. Yeah it’s not really diy nor replacement cost only, but it’s just not that bad relative to the cost of the device. Sure I’d rather spend $20 and replace my own battery, but if I’m spending $1,000 on a new phone, then $99 every 3-4 years for batteries is just not that bad
Betteridge’s law of headlines: “Any headline that ends in a question mark can be answered by the word no.”
„Is drinking Paint thinner really as bad as everybody says?“
Well. It could be worse than what everybody says
is the poupe deck really what i think it is
No.
Corollary:
How not following trends and drinking paint thinner boosted my B2B sales
Are we talking about water-based paint?
I believe that paint thinner does contain water
Water-based paints can be thinned with water, so technically water is a paint thinner… which is safe to drink.
Not if it’s for oil based paints.
You joke, but I actually know some contrarians that would legit try it if this was a headline they saw.
Maybe it can be modified to something like:
“Any headline that ends in a question mark can be answered by yes or no, whichever seems the most obvious.”
Nope:
Betteridge’s law of headlines is an adage that states: “Any headline that ends in a question mark can be answered by the word no.” It is based on the assumption that if the publishers were confident that the answer was yes, they would have presented it as an assertion; by presenting it as a question, they are not accountable for whether it is correct or not.
That’s no longer true. As reporting quality continues to decline and headlines focus more and more on outrage clicks straying further and further from the content, all too many can now be answered with ”n/a”
TL;DW: No
Ok, before i watch the video, no damage is not what great scott found from his testings… ( https://youtu.be/iMn2yVoEqPs ).
so i have no idea what to believe anymore, but my (based) experience is that it does damage it. Ill have to watch later.
Yea, but that wasn’t a great rest. I love Great Scott, but a lot of comments fairly call out his conclusion.
Most (all?)phones don’t charge at full speed to 100% charge, they fast charge when the battery is almoast empty, and charge slower the more full it gets.
Right, so basically he removed the software aspect in his tests which removes systems to protect the battery. I assume without them, it is damaging, like what great scott found.
Ye, he should have continued his experiments then!
It’s a true conclusion, though, although it’s not real world applicable.
It is, if you are just dealing with bare batteries without any kind of protection, but if you are dealing with cellphones/modern smart devices, not so much
Those circuits he made up doesn’t take into account that the phones have built in protections that alternate the input based on charge level.
I’ve got some devices I’ve been fast charging for 8 years; it seems to be more of a problem as the device ages; but that’s offset by having it ready to use again quickly.
I always thought that charging beyond 85% or so is what degrades batteries. The LiPos of my quadcopter actually actively reduce their charge if left sitting somewhere for a longer period of time. To prevent them from going up in flames.
The idea with fast charging is it’s going to generate more heat. That extra heat is what damages the batteries life
Video from the same guy.
Thanks, I’ll watch this
It does, but the battery charge controller in your phone already does that. What it shows you as 0-100 is 20-80 of the actual battery. Others may or may not.
What you call 0% or 100% on a battery is an arbitrary number anyway. Absolutely never do this for safety reasons, but back when I worked for a battery lab I did experiments where I discharged cells to below 0V.
In a previous job I once evaluated some returned product that wasn’t having the best battery life or wasn’t working right. It was specialized expensive equipment that used regular alkaline batteries.
TL;DR: ordinary batteries can have negative voltage if you don’t give a fuck and just mix your old and new ones in a drawer before you put them into your high-cost life-saving equipment.
Do you have more info on that?
Lithium-* batteries don’t actually have any specific useful numbers. It’s something like this (the actual numbers are pulled out of my ass and depends on battery time and test parameters and even then I’m simplifying):
-
At 0 volts, the battery is dead.
-
At 1 volts, the battery is practically dead.
-
Discharging to 2 volts kills it after around 100 times.
-
Discharging to 3 volts kills it after around 10 000 times
-
Discharging to 3.5 volts kills it after 100 000 times
-
Charging to 4 volts kills it after 100 000 times
-
Charging to 4.2 volts kills it after 10 000 times
-
Charging to 4.3 volt kills it after 1000 times
-
Charging to 4.4 volts kills it after 100 times
-
Charging to 4.5 has s significant chance of it catching fire
Now choose how many charge cycles you want it to survive, and you know which voltage to consider 0% and which to consider 100%. The bigger difference, the bigger capacity with the same battery.
This is why a phone with 0% battery can tell you that it’s out of battery.
You can also adjust what “killed” means. Is it when battery capacity is reduced to 80%? 50%?
I have to repeat - the numbers are not accurate, and this is strongly simplified.
It’s just an illustration of what 0% and 100% means it’s just where you are on the useful range, according to the manufacturers definition of useful.
-
The battery has a charge curve. What does the most wear or damage to the battery is the ends of the curve - either deep discharging the battery or charging it up fully to the point where it cannot take any more charge. It’s up to the manufacturer where they want to put 0% and 100% on the curve - to protect and extend the life of the battery most manufacturers don’t put 0% and 100% at the extreme ends of the curve.
A cell’s voltage will change with how much energy it stores, but if you keep applying current to force more charge to move you can cause voltages to be quite far outside of the proper range. However you don’t want to do this as at minimum you are damaging the materials in the cell, or worse, cause a significant safety hazard where the cell could catch on fire.
You can look at the Discharge Curve of a cell which compares voltage vs capacity, as a rule of thumb, essentially the steeper the curve changes, the more damage you are doing to the cell by operating in the range.
Best source I can find: https://eugen-barilyuk.medium.com/how-i-realized-android-battery-percentage-wasnt-serious-enough-0310e484d874
3.7v is 0%, 4.2v is 100%. But a lithium battery can go higher and lower, it’s just that doing that can harm the battery, perhaps spectacularly. OEMs just narrow the voltage range to extend life. When you set a charge limit, it narrows that range further.
You’ll find that based on 3.7 - 4.2 that most li-ion batteries are indeed charged from 0-100 and not 20-80 as you previously claimed. Manufacturers have no reason to overprovision consumer products that are made to be replaced in 5 years or so.
Yes, that’s what I said. You could go higher and lower, and it would be reasonable to do for a short-life device, but they reduce it to extend the life. Mapping voltage to percentage is arbitrary.
Something is off with the link’s measurements. 3.7V is a li-ion cell’s nominal voltage, not its lower limit. Typical operating range is 3.0V - 4.2V. No battery chemistry I’m familiar with would have a lower cutoff as high as 3.7V.
This is the type of scientific method that can put all this nonsense to rest. I really appreciate their work proving that the difference between fast/slow/30-80% is insignificant to the majority of people.
Thanks!
Battery lore has been cargo-cult woo since the NiMH days… most of it feels like manufacturers saying “oh, I’m sorry you didn’t get our advertised life, you must have done something wrong.”
And with that, hopefully we can put this argument to rest.
wow… the idea that the anecdotal evidence of some youtuber should be the proof, not the engineering and chemistry knowledge of people who designed the battery and charging system and know how it works, is on par with the belief that global warming is caused by farts of the turtles carrying the earth. sad noises.
Which part contradicts what the engineers or scientists think?
This isn’t a fair like-to-like test though. They used iPhones, which use one battery and then for their 120W test they used iQOO 7, which has two batteries that charge in parallel. They aren’t testing the charge rate effects on a single battery, but just how different phones behave.
While it’s an okay test to see how certain models of phones hold up, it’s not a test for longevity of a single battery using fast and and not-as-fast charging.
So the title, as it often is these days on YouTube, is misleading.
No they did a fast and slow charging group for iPhone, and also did a fast and slow charging group for Androids. Did you not pay attention.
The video was pretty poorly structured to be honest, should have been longer with better information and they didn’t post their data anywhere to read. I mean they had ~30 seconds just growing plants…
But the point stands, they weren’t testing 1 to 1 on batteries (hard to do anyway). There’s good reasons for why manufacturers havent just cranked it all to 200W charging.
The video isn’t a sudden revelation, we already knew how batteries behave, they’ve been tested in labs under much more strenuous conditions too.
That’s a great TL:DW;
Now I want an iPhone that can charge in 20 minutes. :)
Wish granted, the battery is now small enough to slow charge to full in 20 minutes.
Tap for spoiler
The iPhone air is great, isn’t it?
As humorous as this sounds, this is not at all how battery chemistries works.
Some chemistries just charge faster than others.
for the common types of Lion or Lipo batteries, they max out pushing 2C which is around 30 minutes.
For something like LTO, where you lose capacity/density, you can get that up to like 4C (very rough numbers here as this all depends on the temperature of the battery while charging, age and other factors).
So like… this could have been accurate if this was referring to switching to LTO, but afaik, no one makes LTO batteries in this form-factor (not that it can’t be done though).
So put in a big-ass battery and artificially block it at 20% for “full”? 😁
I’ve been a “Pro” user for as long as they’d had that distinction vs. lower end and the “it’s a small tablet” size.
He he Xiaomi 120 watt charge. 19 minutes from zero to full. Well I only have tried from like 12% to 80+ because that was more than enough and I wont let it go to zero-zero. I don’t use it regularly, not because I fear for my battery but it does get the phone warm and warm/cool cycles are bad for electronics.
The day the battery degrades I’ll just have it swapped for a new one, I think we’re far enough into the battery revolution to no longer really care about all this any more.
That’s pretty awesome
modern phones last long enough , that you likely wont see significant degradation unless you somehow using it for 10+years. most people would have switched phones multiples by then.
Is this because it’s using two-cells though, or is it comparing charging one cell vs multiple.
I think this accurate or close to it for phones but my laptop battery a Dell has degraded very quickly through 50 plus or more cycles of battery like 15 percent. It went from 59wh down to 50wh and it ebbs and flows. Runs Linux mint and installed power top and some other low power mods to help dumb things down to conserve. I feel like arm processors vs x86 are wildly different.
What kills the batteries is keeping them at 100% charge all the time, especially when the laptop is hot. Some laptops do have the ability to limit the maximum charge. Setting the maximum charge to 60-80% when the laptop is going to be plugged in for a while will extend the battery life. It is necessary to occasionally do a full charge to keep the capacity sensor calibrated though.
Yeah, but it’s my 0.5% /s
