In my pixel 5 for the past 2.5 years I charged using the "adaptive battery" slow charging function. (Which charges the phone in like 6 hours).

And during the day I charged up to 80% or 90% when my battery was going low for the rest of the day.

Also I was charging the phone every 2 or 3 nights because in the pandemic I was not using it a lot.

I think now the battery life is about the same. Maybe 5% worse than new. But it is also hard to test this because the os and the apps and the usage changed between day 1 and today.

An app called "Batt" reports 564 charging cycles though.

This is all anecdotal, so take it as you will. At some point in the past I used to be careful to do 80–20, or even 70–30 when possible. It was usually a pain, because I didn't get the full benefit of the battery, and I was always worried I might go above or below my targets. I still had to replace a battery after 2 years.

Then, with my previous phone, I decided not to worry about that and just charge whenever. The vast majority of the time I charged to 100% using fast charge, albeit not overnight. I had that phone for 4 years and it was only in the last year that I felt the battery had got worse. That last year was also after a big software update.

With my current phone, I'm doing 80–20 again—but more often 85–35—without fast charging. A year and half in and the battery has definitely degraded. I have easy access to a charger most of the time, and I use a software feature on the phone to limit charging to 85%, so my current schedule is easy to keep to, but if it wasn't, it probably wouldn't be worth it for me. I'd just accept that, worst case, I have to buy a $50 battery every couple of years to not have to worry about charge levels.

Don't worry about it. As long as you don't let it get down to 0% and as long as you don't fast charge it 24/7, you'll be fine. Don't bother charging it every 10 seconds either. Endlessly taking on and off a charger is not great for a battery. If yiu have 30 mins and you know you'll need the charge by the end of the day, then go ahead. But if you'll end the day with 70% then why are you charging it every few minutes? Relax.

I would stick with the 80 20 charge.

Also, avoid any fast charging options on the phone as it heats up the battery.

Other than that, just enjoy using the phone. Lithium batteries usually come rated for 1000 charge cycles so they should be able to hold at least 80 percent of their capacity if charged daily after three years.

80-20, but don't be too strict about it either.

65-35 doesn't make sense. Yes the battery is at its most stable around 50%, but then you charge it too often and that's not great either, because it goes through heat cycles rather than charge cycles.

Also batteries degrade by themselves anyway, so it really depends on the quality of the battery itself how long it will last. Inconveniencing yourself too much won't give it much extra life.

Just never discharge fully, don't charge fully with exceptions, and charge slowly and you're good.

I am not sure about article, searching for them would need a navigation through a lot of trash articles.

But for lithium batteries, it is often recommended 20-80. Not sure if there are big margins set by honor at 100% and 0% which would make the phone never close to those values. If there are, going to 100% and 0% isn't a huge deal, but still can have some more wear on the battery than 20/80.

I don't know about the specific % of wear. But I'd also assume that battery tech and way of implementing limits can make the degradation % vary. So not sure it would even be useful.

I'm posting this on a near 5 year old device right now. Original battery. Most of it's life it has been on a wireless charger at 100%. Anecdotal, but the lack of daily charge cycles has made the battery last pretty well IMO.

Seems backed up by science:

Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (DoD) determines the cycle count of the battery. The smaller the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses. Partial discharge on Li-ion is fine. There is no memory and the battery does not need periodic full discharge cycles to prolong life.

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

Most important thing in my experience is getting the most slow ass charging adapter with the crappiest cable and use that for charging overnight. Many phones already have some intelligent charging strategy, but you should limit the charging speed (and thus temperature) as much as possible. My OnePlus already only charges to 80% and only finishes to 100% one hour before I wake up, helps as well. Stay away from 0% or 100% whenever possible.

https://lemm.ee/comment/3070853