Even with MagSafe, my wife and I have noticed that we've woken up to a burning hot phone despite it being 100% (although it was rare) but it was enough to make my wife stop using wireless charging. That said, she uses her phone far more than I do, so much so she has to charge every day. Despite this, her battery health is fairly similar to mine.
Wireless charging, especially not MagSafe (meaning it does not align the coils perfectly) definitely generates a lot of excessive heat in the body of the phone. And add that it takes even longer for wireless to charge, that's a lot more heat the battery has to deal with every single time one charges.
Batteries don't like heat. While batteries today handle heat a LOT better than they used to, it's still the #1 way to kill them.
I think that if you keep devices for a while, this is a very important point, and one that requires some consideration. I think that the main question is “why not?” Is there any inconvenience to charging slowly and wired? Do you need that 15w non-aligning wireless charger? Do you have a combination of a phone and a usage pattern which allows some time to charge? (i.e., can you charge slowly without inconvenience?) if so... why not do that? If you can avoid a quick degradation for no tangible drawbacks, I’d do it.
I’m a light user on an iPhone Xʀ with efficient settings on the most efficient iOS version ever, iOS 12. I get 16 hours of screen-on time with light Wi-Fi use and 12 hours of moderate LTE use with outdoor brightness. Do I really need to charge it in one hour with a 20w USB-C charger? Or, alternatively, do I really need a 15w wireless charger? In my experience, the answer is no. Yeah, sure, my iPhone Xʀ with the little 5w charger takes like 4 hours to charge... but it’s fine! I don’t mind, and as somebody who doesn’t replace batteries AND keeps their devices, it’s just all benefits and no drawbacks.
Now, a massively heavy user on an iPhone 8 on iOS 16, perhaps needs to charge two more times because their screen-on time is very low due to their usage patterns. Can they wait? No. Therefore, they will charge as quickly as possible, maybe even with a fast wireless charger because it is convenient. It that ideal? No. Is there an alternative? Also no. Is it wrong? Absolutely not. They can’t wait 4 hours. I have a conservative charging pattern and pay attention to this (somewhat). Would I wait? No, of course I wouldn’t.
If someone upgrades every year, or every other year - it's not going to make a big difference whether one charges wirelessly or not. Look at the Apple Watches... I had an AW3 that I used for years, and my family used for more years up till a few months ago - it got "wirelessly" charged every single day of its life and it was fine. Yes, not exactly an exact equivalent of a phone, but we have posters here who claim to wirelessly charge for years with no detriment to battery health. In most of the iPhone battery health threads people notice their health going down - wired or not, even those who 5w charge their Pro Max. I think people just notice it because the battery health threads only recently exist and Apple now shows it vs neither before.
Battery health loss usually tapers off and levels out. It's not like a glass of water being constantly drained. It should level off. That's why you can old devices with 8x% and sometimes thousands of charges. It's the way batteries have always been. We just never had visibility until the health % reader was visible to end users without special software/hardware.
There has been a massive explosion of battery health “panic” which was a rather unfortunate consequence of the throttling issue. People just never cared, and now battery health is incorrectly blamed on every battery life issue.
Battery health is irrelevant unless the device is severely updated, and the user is a heavy user. A light user will just have enough battery life.
For the longest time I had a 5w wireless charger that I loved. Yes, it took forever but it resulted in the phone not getting very hot. 10w non-magsafe chargers get WAY too hot for me. And MagSafe got too hot for my liking the few times it got REALLY hot.
IMO people use their phones today MORE THAN EVER for heavy lifting items that we never did for our older phones. 4k video, video calling, 4k video recording, heavy resource websites, etc. We're spending more time on our phones than we've ever spent before. Battery tech has not really advanced all that much so we're noticing health dropping faster today than usual. Feature heavy OSs with on device AI (instead server side) also has an effect. My best guess/thoughts/opinion.
I reckon this is the most important aspect: battery health is only relevant if - and only if - three conditions are met:
-The device is sufficiently updated
-The user is a heavy enough user
-Battery health is low enough
Like you said, the number and proportion of people who meet all three conditions has skyrocketed. Couple to that the mass “panic” after the throttling issue, and the current battery health focus is both understandable and predictable.
I've always had great battery health/life on my phone but I'm a super light user - I use my MacBooks for reading, video, talking, etc - I could charge my iPhone 14 Pro Max every 3 days if I wanted.
Me too! The times I’ve let my iPhone Xʀ drop it’s taken at least 3 days, oftentimes more.
