Should I charge my new phone only to 80%?

[Christian]

I agree that 4% is a lot, but I am not so sure that you absolutely have to enable the 80% option to prevent battery degradation. I think it depends on how you are charging your phone: how often, when and under what circumstances (temperature, duration).

I posted about the battery of my iPhone 15 Pro Max 5 days ago:

iPhone Slowing Down Before New iPhone Release

I never had such significant battery degradation after one year. My iPhone 15 Pro Max right now: Battery health - Normal Max Capacity - 100% Cycle Count - 213 I don’t use the 80% max charge setting. The iPhone gets its charge daily during the night between 3:30 and 6:30 am via the Belkin Boost Charge Pro 3-in-1 Wireless Charger (the charger is sitting behind a smart plug that turns the power on and off at the times mentioned above).

Apple apparently is doing a very good job preserving your battery with the standard setting for optimized battery charging, if the iPhone is able to reliably predict when and how you are charging and picking up the phone. My way of charging three hours on a Belkin Wireless charger from 3:30 to 6:30 am (the charger is receiving power only during that period from a smart plug) has the result that the iPhone starts charging at 3:30 and until it reaches a healthy charge level of 80%. And finally it pushes the battery to 100% not much before 6:30 am. My result: each day an iPhone fully charged at 100% with a battery capacity of 100% after one year. I am impressed.

I have no CarPlay, so my iPhone is not charging in the car and I do not charge it apart from this nightly session. My phone is sitting on a stand in the office by day - with no wireless or wired charging connection.

The 80% setting may be a good idea, especially if the iPhone is connected to a charger very often (wired CarPlay connection, stand with a built-in charger and so on). But if not… I don’t know. It is nice to have the actual capacity available if you need it. Unexpected things can happen. A few years ago, I had a little accident and had to go to the hospital. I was so glad that my iPhone was fully charged back then: when I woke up from the surgery at about 3 am, my iPhone still had about 30% charge and it was only in the morning when I was able to get it charged again (when I was able to get hold of a charger again).

EDIT:

I think, this user has a point (Macrumors forum):

The more damaging part is keeping the device at 100% for longer periods of time. Charging it once and then using it is less harmful than keeping it at 100% overnight. (…) But aside from 100% charging, draining it to 0-20% also does harm.