People who charge/discharge between 20-80%, how's your device?

I've had a OnePlus 9 Pro since around when it came out in April 2021. Around 6 months later I installed AccuBattery and started trying to keep my phone between 20-80% battery. I still charge it to 100% sometimes, like when I think I won't have access to a charger or will be out for a while, but generally I stick to it. It is also good to do a full charge (<15% to 100%) once every few weeks because it helps the battery stay calibrated and give accurate percentage readings.
In the 3+ years since then, my phone's reported battery health has gone from a little over 90% to ~83-85%. I also almost exclusively use the 65w fast charger that came with my phone (I'm impatient) so that might be hurting my battery a bit more also. Here's the graph of battery health over time that AccuBattery shows me

I'm a little over 2.5 yrs on a Sony Xperia 5 III, I use the 80% limit feature but not as good about keeping above 20%; and avoid fast chargers for overnight charges.
I don't have hard accubattery numbers but still works fine, I end most days pretty low for last year probably but never with range anxiety. No need/desire to increase my limit to 90% or 100% for extra use time yet

On the other hand, my old S22U that I charged multiple times a day with a 9W wireless charger everyday since I got it, without any of these silly 80% limits, had 95% capacity after 2 years and 4 months, according to a 3 month average on AccuBattery.
I have used fast charging a lot as well, considering that phone would barely last half a day due to the SoC

Pixel 7 Pro here going on 2.5 ish years. I think it's made a significant difference. Normally I'd be ready for an upgrade or new battery at 2 years. Accubattery says battery health is still about 96%
- Same. One of the first things I did (after rooting it) was find the kernel 'files' to make it stop at 79%. Battery life seems about the same as the first month I got it.
  I also have a Wear OS watch (TicWatch Pro 3) that I manually charge to about 79% (with Tasker to alert me on the phone when it's there) and it's still using only around 30%/day after nearly 4 years.

I just use my phone's default "adaptive charging" setting where it charges to 80% for most of the night then up to 100% right before I usually get it at ~7-8am
don't know how to look at the health but in the 2 years since I got it I haven't noticed any drain which is a lot better than my old phone by its 2 year mark.
I don't intend on babying my phone though, I can just replace the battery in the future if it's really needed. understand the benefits but I would accidentally leave it unplugged every other night lol
- what device do you have?

3.5 years almost with the Xperia 5ii. Tried between 20 and 80 but for the last year, the battery life was so bad that now it is between 10 and 80 while barely using it. AVG battery SoT discharge rate is 18%/hr according to accubattery. When I got it, it was around 9%. The killer is screen off time which is 2.6%/ hour, over double what it was originally.
Accubattery has been tracking through the phone's entire life and says it is at 70% or so now. Almost 9% per year loss.
Xperias must have super cheap bad batteries because my girlfriend's A52 (a much cheaper phone) purchased at the exact same time, used much more often, and charged to 100% still lasts 1-2 days easily and the battery capacity is at 85% or so. But maybe if I charged to 100%, the battery life would be at 50% of so with the quality of the battery.
- Do you wirelessly charge your device?
  
  The xperia 5ii doesn't have wireless charging, so no.

3 years of it, I went from 99% to 92% on a OnePlus 8T.
My wife who doesn't follow the same guidelines is at 80% life.
I prefer it since I have a pretty reliable charging schedule. And I also have a small 5000mAh emergency charger with a foldable port in my day to day bag. Win win for me.

Can someone explain what the point of limiting yourself to just using 60% of the batteries capacity is, if all you seem to be getting out of it is it staying above 80-90% after several years? Which is far more than you were using anyway?
I have my current Oneplus for well over 3,5 years now, and I never bothered with the battery capacity. I always plug it into the fast charger that came with it overnight.
Battery capacity really is still completely fine. I don't run out during the day and if it does get close (if I'm very heavily using it) I plug it in for 10 minutes and get like half a charge. Which all seems like less effort than I would have to do to keep the battery within 20-80%?
If the battery does end up failing I can just have it replaced, doesn't really cost that much either. But so far it seems the built-in battery protections work just fine.
- The part you missed is that it doesn't have to be all or nothing. You could maintain 0-80, 20-100, 10-90.
  You could also not take it as gospel but just a soft recommendation, trying to get yourself near to a charger when your phone gets to 20, and plugging out at 80 if you aren't in urgent need for more battery life.
  My laptop which mostly just stays on my desk all day, is limited to 79%. This one makes sense I think.
  
  But even if you limit yourself to 80% battery life, so you stay above 80%, aren't you just... limiting your battery life yourself then? Batteries usually have more than 80% of their original capacity left after several years of usage.
  If I just don't bother with doing this, and after 3 years I have 80% capacity left... I'll have the same experience then as people who limit their usage now. Maybe I'll spend 50 to replace the battery if it gets really bad (eg less than 70%), but I've never had that happen to any of my devices anyway.
  I can understand fixing the charge on a battery that's normally not used like a mostly stationary laptop. But for phones I don't see the point.

Xiaomi Redmi Note 10 Pro here. Battery health is at 88% after 3.5 years of solid daily use. So it's certainly paying off, happy to see more and more devices offering a charge limit option now.

I usually do this on my laptops. It's supposed to make the batteries last longer. But not infinitely. I'll end up replacing them after a several years anyways. It's hard to judge for me, since I have nothing to compare it to. And battery technology is making slow progress, plus my habits change and I used to do one charge cycle per workday and now I'm not.

Does anyone know of a FOSS app that can limit charging on Pixel devices? I imagine it would require root, which is fine for my usage.
I'm using one called "Healthy Battery Charging", but it only gives you notifications and you have to manually plug and unplug the device.
- https://github.com/VR-25/acc
- there is ACCA on f-droid. it can automate charging upper and lower thresholds, make your phone run from cable instead of the battery (and no charging) if yours supports it, limit charging speed, temperature, and can also do schedule based rules by time
  
  Thanks!
  Unfortunately, it seems the Pixel/GrapheneOS kernels don't support limiting the battery charge limits :/ I tried ACCA, and it installed the ACC magisk module, but the device kept exceeding the charge limits.
- I use a slow charger. The trickle charge means it doesn't sit as long
- My Pixel 8a has this built in, the setting is called Charging Optimization, and will limit the charge to 80%.
- There's an app called "Battery Charge Limiter (BCL)" on Github or IzzyOnDroid.
- This one is flashable with magisk
  https://xdaforums.com/t/mod-magisk-root-set-charging-limit-to-80-85-90-95-v2.4482011/
- They added the charge limit feature to Pixels officially in the latest update. Settings -> Battery -> Charging Optimization
  Assuming you have a new enough device running the stock OS.
  
  I'm running GrapheneOS, and they unfortunately do not have that implemented yet.

I usually limit it to 80% during the summer, but because I work outside and through the night too my battery can reach very low temperature levels which absolutely hammers my battery life so I let it charge to 100% / or just to warm it up via a small powerbank on my FLT sometimes during the winter months.
As for longevity? I usually go through a phone every year or two so I don't see the wear of of what others are saying in here using their phone for over two years (that's my max), but I feel the 20/80% guideline is a fair one to go by since the reported 100% isn't fully accurate anyway.

I don't have any hard numbers, but I keep my device between 80 and 30, and do not feel any kind of issues about my phone needing to be charged more frequently than normal, but I've only had it for about a year now.

7.5 year old phone LG G6 works fine, almost like new.
- hows the battery health? is it still within 90%?
  
  86% - measured down to 5% charge playing Full HD video at maximum brightness.

I basically never run out of battery in a single day... Unless one of my anomalous 3rd party apps decides to shit the bed. Just use my phone as much as I want, and charge each night.
... That said, I'll still put it to charge occasionally if I'm in the car and below 60% simply because I'm neurotic.

I charge whenever I need, quite often under 20% and my battery starts acting up after about 3 years, when I'm anyway looking for the next flagship. Last 2 phones were Xiaomi