I feel something is missing at the moment with our ability to choose on the device how I want it to charge. Would be nice to plug the phone in and unless I say otherwise it does a nice slow charge even if the cable and charger is capable of more. But if I press a button on the front after I plug it in then I can select fast and it goes as quickly as the combination allows. Its irritating to have to have different chargers for this to preserve the battery.
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.
> 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
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.
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...
Totally agree. Tbh I never needed the phones to become as thin as cardboard. At the cost of sacraficing the ability to easily remove/replace the battery I certainly never wanted it.
>I never needed the phones to become as thin as cardboard
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.
PD was never deployed for USB-A and was removed from the most recent standard. The grandfathered nonstandard charging protocols will linger around so long as type-A ports are the default.
Adaptive Charging on Pixel devices gets most of the way there: it will learn how long it's typically on the charger each day, and automatically slow the rate of charge to match, so that it finishes approximately an hour before you usually unplug it.
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.
Another problem is the constant charging and discharging of battery while connected to external power. I believe the latest pixels got or will soon get the ability to run directly off the wall when connected to certain chargers.
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.
> Another problem is the constant charging and discharging of battery while connected to external power.
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.
It is absolutely too much work. It's incredibly easy to get bogged into the weeds of config stuff like this and almost no one will care. if they did, I bet it's turn into a cluster of hearsay about magic settings that make almost no practical difference.
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.
I don't like the 80% option because every time I'm leaving the house for extended periods, going hiking or traveling I think "is it worth it to go through 3 settings screens to take an extra 15% charge with me?" 15% is a micro optimization and it was easier when there was no option and I never thought about it. I want to think about other things, not my phone's battery capacity.
Yeah but in android or something this would be just another "quick settings tile" like the "flashlight" or "night light" or "battery saving mode". You could call it "overcharge mode" or "extra battery mode", and like the "night light" mode it would get disabled once you reach a full charge, so you don't have to dig into settings to turn it off again.
I use ACCA[0] to select my charge rate and limit. This can also set battery idle mode (power from USB without using the battery) when the charge limit is reached if the hardware supports it. I usually limit it to 60%, and charge at 500mA when I'm not in a hurry.
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.
100% is always just an arbitrary value chosen by the device or battery manufacturer, there's no 100% level inherent to a battery. Unfortunately there's very few manufacturers that will tell you their estimated number of cycles and none (as far as I know) that will give you the number of cycles as a function of charge percentage.
It's not arbitrary. Lithium batteries charging uses voltage termination, and the usual cutoff for 100% on lithium-cobalt batteries (so not LiFePO which is not yet widely used on phones) is 4.2 volts. It's the same for all batteries I've ever used or heard about. You can charge it to higher voltages, but basically nobody sane does that as it quickly becomes dangerous, and 4.2 is pretty much the standard voltage.
Pouch batteries straight from distributors might all recommend 4.2V, but what's actually used in phones varies a lot. The Samsung Galaxy S21 for example charges all the way to 4.4V. I don't have a huge sample size to work with, but I have seen a number of recent Samsung batteries degrade alarmingly fast, likely because of this.
According to [1], the S24 has gone all the way up to 4.45V.
My Galaxy S21 lets me pick between normal, fast, or super-fast charging in the settings. Not quite one tap, but it does let you do it.
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.
For sure, but for terms of battery wear all that really matters is the time to charge. Under 1 hour is getting into the realm of 'really fast' and heat inside the cell starts to become an issue.
My hack is to only use fast charging bricks, but at home I charge my phone wirelessly. So that means in practice I rarely fast charge it.
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.
There has been some noise about wireless charging causing faster battery degradation because the batteries are usually warmer with wireless charging. Could be a specific hardware or firmware defect only on the iPhone 14 line, I am not sure.
>In such a situation, the best solution is slow charging, for which a low-power charger from your old feature phone is ideal.
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%
My Pixel just bases this off of the morning alarm clock. Since I don't like waking to an alarm, this just means that I have a permanent silent 9am alarm.
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 never even strictly enabled it, but I'm a big fan. My pixel 5 from 2020 still easily gets a full day of battery life, and without direct evidence, I suspect always slow-charging has helped with that.
Many phones/chargers with propietary protocols are also equipped with USB PD compatibility. For example, you can pick up some random Xiaomi phone labelled at 90W and expect it to charge at more than 20W with USB PD, or even ~90W on some vivo models.
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.
One thing I was hoping the article would explain is how fast charging actually works: IE, how does the charge controller turn incoming electricity into a full battery?
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.
All charging does is reverse the flow of lithium ions through the electrolyte that happens when the battery discharges.
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.
It's basically as simple as a buck converter that reduces the incoming voltage.
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.
> 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
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.
Anecdotally speaking, the 80% limit seems to be key to better battery aging long term.Anecdotally speaking, the 80% limit seems to be key to better battery aging long-term.
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.
I don't think Apple was the first to use the magnets to align the phone to the charger. I think I had a nexus 5 that had the magnets in the phone and google Qi charger -- that would perfectly align the phone and charger.
Pretty sure magnet alignment was part of wireless charging with the Palm Pre, and I'm not even a Palm person (I did have an IBM branded Palm Pilot, but it was very outdated when I got it for almost no money, and it didn't call to me)
Unfortunately I’m not sure this article is good, as it doesn’t seem technically sound.
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.
It is annoying that while the connector itself is now finally standardized, the details of implementation diverge. So while you may be able to charge, it'll be slow charge.
This was my complaint when the connector was standardised. There’s also no guarantee that the USB c cable you buy will support it even if your phone and plug do.
In China, replacing an Android smartphone battery is relatively inexpensive—around 100 RMB (approximately 15 USD) for a full battery replacement service. Therefore, we treat it as a consumable item and don't worry much about battery wear. Fast charging and reaching 100% charge are what matter most, as battery concerns shouldn't interfere with my other priorities.
On a rooted phone you can install acc which lets you set a maximum percentage to charge to, percentage at which the phone shuts down, max charging current and voltage, max charging temperature, etc.
You may already know this but getting 12V out of a 15V PD is relatively straightforward with either a linear regulator (less ripple but less efficient) or a buck converter (more ripple but more efficient). The Internet is full of very inexpensive boards that do all that.
I disagree. 12 V is not that much for an adult when you put it on your tongue, but with today's ubiquitous technology in everything, a toddler that puts everything in his mouth, will lead to a lot of distress and fears. I prefer the existing 5V. I suspect you are young and still not a parent.
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.
> I disagree. 12 V is not that much for an adult when you put it on your tongue, but with today's ubiquitous technology in everything, a toddler that puts everything in his mouth, will lead to a lot of distress and fears. I prefer the existing 5V.
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.
This does not make sense as PD needs to negotiate with the device to get anything more than 5V. Putting random cables in your mouth won't result in getting 12V or even the 48V that PD can output.
Today, a charger is a full-fledged computer with more processing power than the Apollo 11 spacecraft that brought humans to the Moon. Before the charging adapter starts pumping the voltage, it must first communicate with the smartphone. Incompatibility of the communication software protocol is the reason why a smartphone with USB PD, for example, cannot fast charge from a VOOC charger.
Read on technical details of fast charging technologies. Find out why the best charger – is your old feature phone's charger.
I feel something is missing at the moment with our ability to choose on the device how I want it to charge. Would be nice to plug the phone in and unless I say otherwise it does a nice slow charge even if the cable and charger is capable of more. But if I press a button on the front after I plug it in then I can select fast and it goes as quickly as the combination allows. Its irritating to have to have different chargers for this to preserve the battery.
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.
> 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
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.
[1] https://chargie.org/product/chargie-c-basic/
I had never thought such thing existed commercially. Mainly because I had looked for it myself in addition to asking about it without results.
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.
will change their phone regularly
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...
Feel like all of this would be a bit irrelevant if we just had easily replaceable batteries. Phone batteries don’t cost that much.
Rather than worrying about charge speeds and charge %, I’d rather just slap a new battery in after 4 years.
Totally agree. Tbh I never needed the phones to become as thin as cardboard. At the cost of sacraficing the ability to easily remove/replace the battery I certainly never wanted it.
>I never needed the phones to become as thin as cardboard
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.
PD was never deployed for USB-A and was removed from the most recent standard. The grandfathered nonstandard charging protocols will linger around so long as type-A ports are the default.
Adaptive Charging on Pixel devices gets most of the way there: it will learn how long it's typically on the charger each day, and automatically slow the rate of charge to match, so that it finishes approximately an hour before you usually unplug it.
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.
Another problem is the constant charging and discharging of battery while connected to external power. I believe the latest pixels got or will soon get the ability to run directly off the wall when connected to certain chargers.
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.
> Another problem is the constant charging and discharging of battery while connected to external power.
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.
It is absolutely too much work. It's incredibly easy to get bogged into the weeds of config stuff like this and almost no one will care. if they did, I bet it's turn into a cluster of hearsay about magic settings that make almost no practical difference.
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.
I don't like the 80% option because every time I'm leaving the house for extended periods, going hiking or traveling I think "is it worth it to go through 3 settings screens to take an extra 15% charge with me?" 15% is a micro optimization and it was easier when there was no option and I never thought about it. I want to think about other things, not my phone's battery capacity.
Yeah but in android or something this would be just another "quick settings tile" like the "flashlight" or "night light" or "battery saving mode". You could call it "overcharge mode" or "extra battery mode", and like the "night light" mode it would get disabled once you reach a full charge, so you don't have to dig into settings to turn it off again.
I think that's the case on my mom's Android. And it's a basic Samsung galaxy something-or-other, nothing customized.
I use ACCA[0] to select my charge rate and limit. This can also set battery idle mode (power from USB without using the battery) when the charge limit is reached if the hardware supports it. I usually limit it to 60%, and charge at 500mA when I'm not in a hurry.
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.
[0] https://f-droid.org/packages/mattecarra.accapp/
Charge it up to 80% in the firmware but show 100% in the UI. Wear leveling algorithms probably do something similar already.
100% is always just an arbitrary value chosen by the device or battery manufacturer, there's no 100% level inherent to a battery. Unfortunately there's very few manufacturers that will tell you their estimated number of cycles and none (as far as I know) that will give you the number of cycles as a function of charge percentage.
It's not arbitrary. Lithium batteries charging uses voltage termination, and the usual cutoff for 100% on lithium-cobalt batteries (so not LiFePO which is not yet widely used on phones) is 4.2 volts. It's the same for all batteries I've ever used or heard about. You can charge it to higher voltages, but basically nobody sane does that as it quickly becomes dangerous, and 4.2 is pretty much the standard voltage.
Pouch batteries straight from distributors might all recommend 4.2V, but what's actually used in phones varies a lot. The Samsung Galaxy S21 for example charges all the way to 4.4V. I don't have a huge sample size to work with, but I have seen a number of recent Samsung batteries degrade alarmingly fast, likely because of this.
According to [1], the S24 has gone all the way up to 4.45V.
[1]: https://old.reddit.com/r/techsupport/comments/1ayqveg/samsun...
Don’t forget a “defeat” mode where the system detects you’re a reviewer and really truly does charge to 100%.
My Galaxy S21 lets me pick between normal, fast, or super-fast charging in the settings. Not quite one tap, but it does let you do it.
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.
https://en.m.wikipedia.org/wiki/Quick_Charge
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.
For sure, but for terms of battery wear all that really matters is the time to charge. Under 1 hour is getting into the realm of 'really fast' and heat inside the cell starts to become an issue.
My hack is to only use fast charging bricks, but at home I charge my phone wirelessly. So that means in practice I rarely fast charge it.
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.
There has been some noise about wireless charging causing faster battery degradation because the batteries are usually warmer with wireless charging. Could be a specific hardware or firmware defect only on the iPhone 14 line, I am not sure.
Most multichargers solve it by having faster and slower charging ports. This may be not an app, but a nice / simple hardware based solution
>In such a situation, the best solution is slow charging, for which a low-power charger from your old feature phone is ideal.
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%
My Pixel just bases this off of the morning alarm clock. Since I don't like waking to an alarm, this just means that I have a permanent silent 9am alarm.
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 never even strictly enabled it, but I'm a big fan. My pixel 5 from 2020 still easily gets a full day of battery life, and without direct evidence, I suspect always slow-charging has helped with that.
Many phones/chargers with propietary protocols are also equipped with USB PD compatibility. For example, you can pick up some random Xiaomi phone labelled at 90W and expect it to charge at more than 20W with USB PD, or even ~90W on some vivo models.
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.
One thing I was hoping the article would explain is how fast charging actually works: IE, how does the charge controller turn incoming electricity into a full battery?
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.
All charging does is reverse the flow of lithium ions through the electrolyte that happens when the battery discharges.
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.
It's basically as simple as a buck converter that reduces the incoming voltage.
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.
> 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
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.
Anecdotally speaking, the 80% limit seems to be key to better battery aging long term.Anecdotally speaking, the 80% limit seems to be key to better battery aging long-term.
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.
My iPhone 15 Pro Max, first use on September 2023 is at 98% capacity. Charged mostly on a wireless charger and the charge limit set to 80%.
Iphone 15 Pro here, first use Nov 2023, is at 94% capacity. Mostly wireless charging at 80% too. 290 cycles.
I don't think Apple was the first to use the magnets to align the phone to the charger. I think I had a nexus 5 that had the magnets in the phone and google Qi charger -- that would perfectly align the phone and charger.
Pretty sure magnet alignment was part of wireless charging with the Palm Pre, and I'm not even a Palm person (I did have an IBM branded Palm Pilot, but it was very outdated when I got it for almost no money, and it didn't call to me)
Unfortunately I’m not sure this article is good, as it doesn’t seem technically sound.
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.
> Fast charging to 80% at cool temperatures will give a much better lifespan than charging slowly to 100% in a warm room.
How low do you suggest I should put the temperature in my bedroom, so that my phone would be comfortable fast charging?
It is annoying that while the connector itself is now finally standardized, the details of implementation diverge. So while you may be able to charge, it'll be slow charge.
This was my complaint when the connector was standardised. There’s also no guarantee that the USB c cable you buy will support it even if your phone and plug do.
In China, replacing an Android smartphone battery is relatively inexpensive—around 100 RMB (approximately 15 USD) for a full battery replacement service. Therefore, we treat it as a consumable item and don't worry much about battery wear. Fast charging and reaching 100% charge are what matter most, as battery concerns shouldn't interfere with my other priorities.
On a rooted phone you can install acc which lets you set a maximum percentage to charge to, percentage at which the phone shuts down, max charging current and voltage, max charging temperature, etc.
Wish they’d kept 12V throughout the PD standards. So useful for hobby stuff
You may already know this but getting 12V out of a 15V PD is relatively straightforward with either a linear regulator (less ripple but less efficient) or a buck converter (more ripple but more efficient). The Internet is full of very inexpensive boards that do all that.
I disagree. 12 V is not that much for an adult when you put it on your tongue, but with today's ubiquitous technology in everything, a toddler that puts everything in his mouth, will lead to a lot of distress and fears. I prefer the existing 5V. I suspect you are young and still not a parent.
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.
> I disagree. 12 V is not that much for an adult when you put it on your tongue, but with today's ubiquitous technology in everything, a toddler that puts everything in his mouth, will lead to a lot of distress and fears. I prefer the existing 5V.
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.
Yep, it's even mentioned in the article - it's maximum of 48V @ 5A for total of 240W.
This does not make sense as PD needs to negotiate with the device to get anything more than 5V. Putting random cables in your mouth won't result in getting 12V or even the 48V that PD can output.
This comment is incredibly rude and patronizing. Many young people are parents and many older people are not.
also that's not how USB-PD works...
Today, a charger is a full-fledged computer with more processing power than the Apollo 11 spacecraft that brought humans to the Moon. Before the charging adapter starts pumping the voltage, it must first communicate with the smartphone. Incompatibility of the communication software protocol is the reason why a smartphone with USB PD, for example, cannot fast charge from a VOOC charger.
Read on technical details of fast charging technologies. Find out why the best charger – is your old feature phone's charger.