this post was submitted on 09 Nov 2025
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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.
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
Sure, if the manufacturer sets it to not charge to the max. I'm saying some manufactured charge to the max by default, hence why that setting is useful.
I think you're leaning too much into the false assumption that "the max" is some final and definite thing.
Batteries aren't charged from "empty" to "max", there is no "max". They're charged from one voltage level to another which isn't in a percentage value. How do you think your phone knows what percentage a battery is at?
"The max" is the highest voltage the battery can safely store with reasonable losses, and "empty" is the lowest voltage the battery can safely charge from. Or something like that, I'm not a battery engineer. There's surely a bit of buffer here since users will use it outside of ideal circumstances (ambient temperature, heat dissipation, etc).
Regardless, those numbers come from the battery manufacturer. I'm guessing phone manufacturers add some extra buffer given the properties of the phone (heat generated by electronics, heat dissipation of the case, etc).
None of that has anything to do with what I'm talking about.
The 20-80% range is on top of that and is based on efficiencies in battery tech. That's the sweet spot of battery longevity, and some phone manufacturers limit charging to the top end and most (all?) warn when you hit the lower bound. But not all manufacturers report 100% when it hits that upper bound of that range. Many do, but not all. Some report 80% and let you bypass it, and some don't cap that upper bound.
Your first paragraph pretty much agrees with the grandparent of this whole thread. What constitutes "max" is something that the battery manufacturer and the phone manufacturer come up with.
You said "some do this some don't". It doesn't make any sense at all. All manufacturers have to decide what 100% means. There is no some do some don't.
Obviously not. Might as well stop at that then
The OP said "all phone ma manufacturers stop charging at 80%." That means phone manufacturers have a definition for 80% and 100%, and they use 80% universally while showing 100%. The first part is true, the second part isn't. Some manufacturers show 100% when it's actually their definition of 100%, meaning charging to 80% manually on those phones has value in prolonging your battery, whereas charging to 80% manually on the phones that cap at 80% doesn't have value.
Lol um no they didn't.
Someone else mentioned "80%" when you didnt understand the first comment, but they didn't say "all manufacturers stop at 80%" either.
You have got to be trolling at this point to be this obtuse
Original comment:
My response, which was a small clarification:
And the follow up from a different user:
And my response:
Then our conversation started. That's the context. Here's your first comment:
And then my response:
My point is and has always been that this isn't universal, so don't just assume that your phone stops charging at 80% if battery longevity is important to you. Check if your phone does it so you can know.
If anyone is trolling here, it's you.
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.
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.
https://www.wired.com/story/how-to-improve-battery-life-tips-myths-smartphones/
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.
Source?