Most high-quality LiPo-powered devices already do this at the hardware-level. The 100% level you see on the software is usually 80% actual charge on the battery.
This sounds like the battery and the charger's problem to handle, not mine.
All this tech, all this automation for every damn thing, and people keep coming at me like I'm supposed to do everything manually with my fingers and eyes and maybe an alarm or something to keep me on schedule. No. Stop it.
Make the charger handle it, or shut up. Make the phone, the charger, and the battery handle it together, you know, with digital automation. Do not even mention it to me.
Just build phones with the understanding that batteries are consumables and make them easy to replace and standardized. Then swap in a new $5 battery when you need to so. Make the raw materials reclaimable too of course.
If you don't ever charge it to over 80% then it's effectively already degraded 20% since the day you got it. I'll rather just use it as intented and then replace the battery when it no longer holds charge. That's just one of the reasons I didn't buy one with built in battery.
I don't like this article because it misses some of the more important details around how to lengthen your device's life and why you may or may not want to keep your battery at a specific state of charge.
State of charge is pretty arbitrary, your charging circuit could charge between 3.0V and 4.2V (pretty typical), or it could charge between 3.2V and 4.0V and still show 4.0V as being 100% charge. Different chemistries can have slightly (or significant in the case of LFP) different voltages. The cynic in me wouldn't be surprised if eventually 100% becomes ~4.35V because it makes their device look better to tech reviewers, but then have it default to only charge to 4.2V because it still gives suitable device life.
The most important factors in how long your device's battery will last are temperature and how deeply you discharge the battery. Discharging your phone down until it dies does way more damage than keeping it charged at 100%.
At some point practicality comes into it, you would get even more total energy out of a cell if you kept it between 40% and 60% all the time, but obviously it isn't very practical to only use 20% of your phone's available capacity in day to day use.
Consider how long you are storing your device. If it is always plugged in or won't be used for months, then something like 40% to 60% would be a more suitable state of charge to keep your device at if possible. If it sits on your desk and you need to unplug it periodically and know you don't need the full charge, then sure keep it at 80%.
Personally, I don't stress about the batteries in my devices at all. I generally keep an eye on the power and plug it in when convenient, but target plugging it in before it gets too far below 50%. I've historically had almost zero issues with the batteries in my devices wearing out before I'm ready to replace it for other reasons unless it started out with marginal battery life.
Damn, some of you must have pretty chill lives if paying attention to what level your battery charge is at DAILY is something you want to add to your plates. I mean sure, if there was a setting that allowed you to have the phone automatically cut charging at 80% this might be worth thinking about. But when I charge my phone its during times when I dont have to think about it (Aka 90% of the time, when I'm asleep)
... Aren't devices designed to only charge the battery to 90% (and report that as 100%), because actually changing a battery to 100% is pretty harmful for it?
Depends who you ask. To manufacturers it's a brilliant idea. It's not a mystery that no electrical engineer knows that Li-Ion batteries don't like to be fully charged. It's just that manufacturers realized that charging 100% means you battery will die at around 2 year mark or 600-1000 charge cycles and that will be enough push for some people to buy a new device while at the same time your device seems to last longer on a single charge. Charging to 80% or 85% significantly extends life span of a battery. At that point chemistry almost doesn't degrade.
And it's not just with mobile devices and batteries that this is happening. Engineering with a plan to fail at specific time has become a precise science. Making something that will last forever is not that difficult, just not lucrative to them. Take for example LED lights. Manufacturer states 50k hours at 3.1V for white LED. Reduce that voltage down to 2.5V and you have basically made it infinite but it glows less, so to compensate you'd have to add more LEDs and that hits their income. Big Clive has a great video on the subject.
My samsung n20 ultra has the 85% charge option built in and I've always used it to keep my battery good. Back when it was easier to use custom roms in the 2010-2014 Era there was a lost of them that had custom "stop charging options" like it.
I also have fast/ultra fast charging disabled. If you don't need to quickly charge your phone, it's something else you should avoid.
For steam deck owners it gets a bit more complicated. SD has pass through charging, so once the battery is fully charged and also while it is plugged in, you aren't powering it through the battery like cell phones and most laptops do. It's just running off the USB c power, so if you usually play while plugged in, you aren't cycling the battery, but you are having to allow it to fully charge.
They talk about Apple but Sony phones have had this feature for a while. In the settings you can choose whether the phone is always 100% charged, or whether it charges to 80% (or a custom %) or whether you want it full by the time you wake up.
I use the 3rd option. It stops charging when it gets to 90% and I tell it when I'm getting up, and just before it will charge up to 100 %.
Best of both worlds. Only ever having 80% to start is not nice because you get less juice during the day and need to charge by the evening. Plus battery anxiety. I'd rather have a 100% full battery.
Clearly newer, better battery tech is needed. Plus replaceable batteries.
I'm convinced that apples laptop battery saver feature that's AI powered and decides when to charge above 80% vs just letting you set it to 80% and manually set it to 100% when needed is to cause the batteries to die sooner, because ITS GOD AWFUL AT DOING ITS JOB PROPERLY.
For android users, we can easily set notifications if battery level reach certain range by using apps like Tasker. Before this I set it for full charge. Change it to above 80% just now.
EDIT: tasker proj file in case anyone is interested. Link.
Degraded battery life is rarely the thing that tanks a device for me (sure, it degrades, but it's rarely the reason I replace it). I mean it's great to know about this, but the last four phones I've replaced have been because (a) my old phone didn't work on my new network, (b) my camera failed, (c) my chipset wasn't up to the task of the most recent OS update, and (d) there was a fundamental flaw in my handset and the manufacturer offered a $50 upgrade to their newer model with trade.
Actually, thinking about it, a and b might be switched, but the point stands: it's probably been twenty years since battery life was the reason I upgraded (from a flip phone to another flip phone, iirc).
If 80% is enough, there is not much to loose that is usually where the battery health finds its plateau after some years.
I rather change my battery once it hits 80% health after two years. I don't want to use it like it would behave when the battery is already dead.
I still charge to 100, but I use a slow charger, so my phone doesn't start to spew flames while it's charging. I wouldn't be surprised if that helped as well (as heat is another battery killer).
I just can't be bothered to handle that shit manually.
I do this myself. I have mine set to 81% as the max and get a notification when it hits that level and then I get another notification when it hits 30% so I can plug it in.
There used to be a magisk module that would charge the battery intelligently and stop before b
Full charge but I don't think it exists anymore sadly, or at least I haven't been able to find it