Its pretty bad that only recent phones have started to add the ability to charge to only 80% to keep the battery in the optimal zone to extend the life given how long we have known that 80% was the optimal maximum. There are also a few phones now able to power themselves from USB without using the battery which if you leave them in chargers a lot throughout the day and night seems like a good feature to have to preserve the battery further.
Maybe all the complexity around this is too much and people just want to plug it in and quick 100% as quick as possible and will change their phone regularly but its pretty wasteful. We ended up going through lots of special chargers that all do very similar things and now you get a device and it often doesn't even come with a cable let alone a charger and you are digging through the specs of your charger, cable and device to work out if its all going to mesh correctly together or you'll be stuck on slow mode. We have ended up with so many standards for getting quicker than the basic charge its going to take a while for all these devices to age out and in the meantime chargers are going to be doing QC and PD and a host of other things besides for a while.
It's this, 100%. The nerds that care about charge temperature and battery degradation and proliferation of incompatible charging standards are a rounding error, most people just want to know it can charge fast in case they forget and need to leave soon.
I am happy with my Chargie [1], an interposing dongle which provides a Bluetooth receiver and app that lets you set arbitrary preferences on your phone and fast charge, slow charge, or turn off the charger at configurable state of charge setpoints or times.
It needs an app but doesn't mention interoperability. There, I said it. It is not perfect.
At least they allow you to set-up-in-app-and-use-without-app which is more than many products.
Now imagine the same product but with different physical toggles or buttons on it for all the different charging modes. No apps. That'd be great.
How would it determine when the attached device reaches 80% state of charge? Or what the time of day is? How could you program a schedule for weekdays and weekends?
There are good reasons for Chargie to have an app, it's not just there to siphon up analytics.
The same way it determines that the battery is fully charged. It is a solved problem.
Rather than worrying about charge speeds and charge %, I’d rather just slap a new battery in after 4 years.
I’ll take the reduced size, lower weight, sturdier construction, and better waterproofing I get from the current build style.
Saving tens of dollars and an hour or two of my time every 4 years isn’t worth the compromise.
All to have a slight thinner device.
And it is only thin until you put on the bulky case. If phones put a real battery and intigrated basic protection, it would still be thinner than the current small battery/outer case situation. Most people don't need tank-like Otterbox protection, they just need something that keeps bumps and small drops from shattering something.
Battery life is much better now. I put phone on wireless charging pad and it is always charged when I need it. I use it all day and still have power. I carry power banks in bags if need it. External battery is better because it works with any device without having device specific batteries. Also, there are now batteries that magnetically attach to phone and wirelessly charge.
It would be nice if it was easier to replace battery, but don't need replaceable battery every day for something that happens in couple years.
The big difference is simply that battery chemistry has improved and new cells have more energy per volume.
There is no technical reason at all that we can't have replaceable cells with the capacity of current internal batteries. Unless you count waterproofing, which I've always viewed as nothing more than an excuse for planned obsolescence. There are definitely ways they could engineer water-resistant phones with replaceable cells.
The same way my Game Boy worked in the nineties with NiMH batteries. Why did we abandon that pattern?
"Don't you want to be online all the time, so we can spy on you ?" . Sincerely, FAANG /s
There's a manual option to turn it off (charge at full rate this time only), but not to manually turn it on (such as giving it a target time to be fully charged). Older Pixels used what time the alarm was set as the target time to finish charging, which I preferred as someone who doesn't wake up at the same time every day; I'm not sure why they took that away.
(I do have an old, lower wattage charger beside my bed to limit the charge rate)
I would love to see this technology come to all phones. 80% cap might be controversial but I don't think what I am asking for is controversial in the least.
Is that actually the case? Anecdotally, all my devices which spend 99% of their time connected to external power show the least degradation in reported capacity and the best preservation of their original battery life. I'm talking about iPhones, macbooks and hp laptops.
For the latter, I have two basically identical ones, one for work and the other for home (same model number, same generation, same battery p/n). The home one rarely if ever runs on battery, it has something like 50 cycles in 4 years. The battery lasts pretty much as when it was new. The other runs often on battery and it only lasts half as much. I doubt it's a lemon, because it's the standard issue laptop at work, and my colleagues' are in the same boat.
My iphone 14 pro's reported battery health has also degraded much faster than my iphone 7's. I use it much more often on battery than the old one which spent 90% of its time plugged in. But since the devices are different, the comparison isn't as meaningful as with the laptops.
Chemically speaking, Li batteries do degrade much faster when kept at 100% for weeks on end compared to being stored at 50%, but not as fast as cycling it. The absolute worst case (without cycling) is being stored at 100% at warmer temperatures, like 40C. They will lose over 10% within a month in those conditions. I highly suggest a laptop cooler for any desk where you may use a laptop plugged in for extended periods.
Additionally, only the cheapest of cheap garbage phones would behave the way you imply. Charge controllers are readily available from TI et al with battery bypass. When the battery is full, the system runs on external power exclusively, except for the top-off charge.
It's really a pretty standard feature. You can get controllers with and without this, but you'd have to be either extremely cheap or extremely dumb to not use a controller with battery bypass in an application like a phone.
Based on my own testing, my pixel 8 will run on USB. No current fluctuations that would indicate battery cycling, just a constant draw. My previous Samsung also behaves this way.
You're right that cycling the battery this way is bad for them, that's why competent engineers don't.
https://old.reddit.com/r/GooglePixel/comments/1ha8tv9/pixel_...
Also, I'd argue it's not obvious that 80% charging is better for most people. You're taking an immediate 20% cut to battery life, and chances are it will take years for it to actually be better than charging to 100%. I guess it's good to have the option, but only if you almost never need that last bit of capacity.
That said "super-fast" charging on it is like 18W and still about an hour from 20%, so it doesn't really qualify as fast charging IMO, and at an hour is certainly not going to be causing any excess battery wear. It's just normal speed.
Quick charge started at 7.5W
My charge "Standard" was set in the time 500mA was supplied by most phone chargers. Just saying I am old.
The arbitrary value is what voltage you stop charging at. You set your maximum cell voltage and stop charging once you reach that voltage AND input current is below a threshold. Once charging is complete, you store the current energy value as the latest full capacity. That value then becomes the 100% mark.
Remember that batteries lose capacity over time. You must continually scale your state of charge percentage to the actual state of the battery.
The final charge voltage is a tradeoff between safety, longevity, and usable capacity. Higher voltages squeeze a few more joules into the cell at the cost of much faster degradation and increased risk of catastrophic failure.
A cycle count figure on lithium cells is pretty much worthless. It depends quite a lot on exactly how you cycle the battery. A 100 to 0% cycle is much, much more damaging that a 100-50% cycle. Higher currents and temperatures degrade the cell faster. Most cell manufacturers I've seen do give cycle counts under specific test conditions, but that's hardly applicable to real use cases.
According to [1], the S24 has gone all the way up to 4.45V.
[1]: https://old.reddit.com/r/techsupport/comments/1ayqveg/samsun...
I used to build quadcopters around 2015, and some of the battery mfgs released "LiHV" batteries, which were supposed to be safe up to 4.35v, however if you actually charged them that high, they would puff up like balloons after only a couple flights. Maybe with the cumulative advancements in the last 10 years, they've been able to push up the max voltage more safely.
Yeah, I need my phone to just last until the end of the day. The charger is on the night stand. To Android's credit, if I have an alarm set, it'll time the charge to reach 100% as the alarm goes off.
With these habits, I've never had to replace my phone due to the battery, so going the extra mile to preserve the battery seems like an exercise in futility...
The Samsung phone I had was pretty good, you had separate options to disable fast charging on either wired or wireless.
But really my solution is quite simple: none of my habitual charging spots have a fast charger, they're all 5V 2A adapters. I do have a couple of fast chargers around the house, I just don't use them unless I really need to. It's a deliberate decision to fast charge.
That and where applicable I limit my devices to 80-90% full charge. My Linux thinkpad has firmware level support for this, it's very nice.
Maybe that's too much fuss for most people, but I'm still using a five year old Pixel 4A on the original battery and its showing no signs of reduced battery performance. I probably wouldn't put in the effort if it was easy to replace the battery, but it is not. I might be a little less aggressive about it if I liked any current phones, but I do not.
There's one for battery protection (the 80% thing) but not for fast charging.
On my current phone I use wireless charging overnight and the 80% limit and I think that gets me most of the benefits of that hacky solution without requiring root.
Yes, it does heat up due to energy losses, but I suspect that's way less hard on the battery than the same amount of heat from actual high current charging (please correct me if I'm wrong).
This means the only drawback is that my phone charging is cost-inefficient.
This is Windows 95 style UI. We don't do that anymore. We are "smart" now. With blockchain security. And you can choose any colour you like, as long as it is a shade of grey. /s
It seems like most Android phones now have a feature that does this, though you have to enable it. Mine asked me to put in the time I go to bed and the time I wake up, and it slowly charges the battery over that time period to 100%
I do hope that USB PD and (to a lesser extent) Qi takeover the charging space. There is really no reason to have every SoC vendor create their own incompatible fast charging standard.
I've been charging my iPhone this way since the iPhone 4 (trickle charging overnight) and have noticed zero improvement in battery degradation performance vs. fast charging.
As a current example, my iPhone 15 Pro, purchased a month after launch, is at 85% capacity.
My launch-day iPhone 15 Pro Max is at 95% battery health. That phone has had the 80% limit enabled since day one, and I very rarely have had to increase it for specific busy days.
My previous iPhone 12 Pro Max very quickly descended to 88% battery health after a year.
My charging habits remain the same: fast and furious Magsafe/Qi/Qi2 charging every time there is a charger nearby (remote worker, so that’s almost all the time).
I do have unpleasant thoughts about the 80% battery charge limit not being available on anything older than the 15, since it turns out it can be sideloaded via Nugget and MobileGestalt manipulation.
Not enough to push me away from the walled garden (these phones are aging better than my previous flagships from other ecosystems), but a reminder of the rough edges in it.
Feels a bit like worrying about tomorrow stealing joy from today
Not at all, I only use around 40% per day.
> in exchange for just one day of simplicity
More like avoiding months of that mental anguish in the future because my phone can still easily handle the 40% I use instead of having degraded down to where that is the limit.
I used to think this way. Spent decades justifying it as a motivator. It's a trap.
It made sense if you were risking your life whenever you went to get food. If you're trying to recreate those feelings by undercharging the battery of your smartphone, you're just bored
I don't see why the best charger is the old feature phone's charger - the point in fast charging is that you don't have to wait too long if in a hurry. That charger is the "best" if only you have almost unlimited time to charge, like during the night.
The reason why I switched to wireless charging was because I had a phone go bad due to problems with the charge port. USB-c ports on my Pixels to tend to clog with dust and other debris, but as long as I use a wireless charger, it doesn't matter.
With PPS (programmable power supply), AFAIK the phone will typically ask the charger for a voltage twice as high as it wants to send to the battery, possibly a bit more to compensate for losses in the cable, then halve that with a highly efficient charge pump (https://en.wikipedia.org/wiki/Charge_pump).
The best (most "gentle") way of charging a battery would likely be a phone that is intentionally not trying to fast charge, connected to a PPS-capable power supply. This would minimize losses and thus heat within the phone without charging the battery faster than necessary. I suspect that the difference to charging off a non-PPS charger is negligible in practice.
Wireless charging creates a lot of waste heat, which isn't great for the battery.
Wireless charging is usually worse long term because of the extra heat the coils create from the waste energy. It's probably about as bad as the really fast charging phones do now though. I principally have mine do a slow charge over night these days though as is mostly last through the day.
Phone batteries need either 4.2V or 4.35V to charge fully, so whatever voltage comes in (5-20V typically) at whatever current, gets reduced down to the correct voltage and current to charge the battery.
https://batteryuniversity.com/article/bu-808-how-to-prolong-...
There is usually some setting to limit charging to 80%, and while it depends on your model and usage, going down from 80% to 30% at the end of the day is quite typical. Then you can charge overnight (preferably using slow charging) back to 80%.
But when you need it (ex: travel), you have the option to unlock full charge and use fast charging.
This is a regular superspeed USB-A connector (albeit with both SSTX/SSRX contact pairs omited). Standard SS USB-A cable would work just fine here:
Are we seriously discussing how fast charging can lead to 1.6% degradation of 2-4$ every 100 days? Maybe it's better to discuss why to replace it at the service center costs 50$
Disclaimer, I was expecting an article with such a title to talk more about silicon anode batteries, or perhaps LTO (lithium titanate oxide) batteries that can charge in about 6 minutes (10C). It’s fine that the article doesn’t talk about that… however some of its other claims are a bit problematic.
> In such a situation, the best solution is slow charging, for which a low-power charger from your old feature phone is ideal. These devices offer a small power output of 2–5 W, stretching the charging process to 5–7 hours depending on the adapter's power and the battery capacity. This way, your phone's battery charges under the best conditions, minimizing degradation. Fast charging leads to up to 1.6% battery degradation every 100 days, according to an experiment comparing 5W and 25W charging on six identical smartphone batteries.
Sorry but that’s not the correct conclusion (or advice). Fast charging to 80% at cool temperatures will give a much better lifespan than charging slowly to 100% in a warm room. The issue isn’t charging speed, it’s the heat, along with time of strain (at high SOC). In fact there are pulsed very high speed charging patterns under testing that show even lesser dendrite formation than standard charging.
For anyone wanting to learn more, I highly recommend battery university. They’re probably the best resource out there on the net for genera purpose info on lithium batteries.
How low do you suggest I should put the temperature in my bedroom, so that my phone would be comfortable fast charging?
If I leave them on, they get warm, and the pods (not necessarily the case) lose their charge.
I’d like to just buy 10 of a given charger, maybe with a couple of adapters for different devices.
What’s the best option today?
Rather than 10 of a given charger, consider a smaller number of GaN chargers with multiple ports, but be aware that many of the "smart" ones will reset all ports if any port is reconnected or renegotiates. I have a "smart" charger capable of outputting 100 W on one port or some mix of wattages on multiple ports (mainly for travel), and a "dumb" multi-port charger that I use both for slow charging of phones and for powering IoT devices that I don't want to be reset. The latter simply has multiple USB-A ports, which lets me charge almost anything - either with an A-to-C cable, or A-to-whatever-that-device-needs (either Micro-USB, Mini-USB, or something proprietary).
Then maybe another slow charger for all those miscellaneous things around the house.
This article has all the info you need to be able to answer that question. But the answer is, it depends what phone brands you use.
I have discovered that certain Anker chargers are happy to supply 12V PD though...and it tends to be their cheaper charger lines. e.g. A2149 while the more expensive ones refuse 12V requests
Also, as a hobbyist, you can pretty much get a cheap PC power supply and transform it in a very professional "every volt and power under the sun" power supply for your hobbies. That's what I did.
But PD not only already has 20V (or 19?) which can do everything 12V can, but I hear there's a new standard for going above 100W, which, presumably, works at an even higher voltage. Not sure how removing 12V specifically helps with the situation you describe.
also that's not how USB-PD works...
Guess what USB-C PD defaults to when you put in on your tongue. Low current 5V. ;)
Most PSUs will happily send 50-100 watt down the 5V line to anything that's connected including childrens tongues while usb-c will top out at 15W without negotiation
So maybe spare me the misinformed lecture about what is safe...
Read on technical details of fast charging technologies. Find out why the best charger – is your old feature phone's charger.