iPhone 15 Pro Max iPhone 15PM: iOS not respecting 80% charge limit

[Mity]

My iPhone 15 Pro Max is currently on iOS 26.4.2. Either starting with 26.4.1 or the update right before it, my iPhone stopped respecting my battery charge limit of 80%. See screenshot showing the phone charging to 96% despite optimized battery charging being on. Has anyone else noticed this as well?

 

[Snørrbjørg]

This will happen with intervalls to calibrate the BMS. Normal.

 

[FreakinEurekan]

Yep the 80% charge doesn't PREVENT it from charging above, it will do that from time to time.

Just "Generally" it'll remain at 80% or below.

 

[Antaris]

This will happen with intervalls to calibrate the BMS. Normal.

I keep forgetting that, thank you for the reminder! It's also tempting to unplug the charger if I see it go above 80 but I hold back as well. Due to heat, I avoid wireless charging and often baby it by using 15W or 25W maximum for the charger mechanism to avoid excess heat. Mostly because cats love heat and if they feel the heat from x feet away, they'll curl up on it which probably won't do the phone any good either...)

 

[doogm]

FWIW, I experimented with charging my iPhone 15 Pro with low-wattage charging overnight (and to an 80% limit) and the battery health degraded as much as my 13 Pro using Power Delivery charging with no limit. Since then I've just used power delivery charging (to 100% over the summer, 95% otherwise) and the battery health loss is the same as it was using low-wattage charging. So, I understand the cat reason, but it's likely not going to change anything at all about long-term battery health.

 

[James6s]

This is interesting. My iPhone 17 charged to 100% yesterday morning with the charge limit set at 85%, which is fine because iOS does this sometimes for battery calibration.

However, this morning it done another 100% charge with the charge limit still at 85%.

Will see if it does the same tomorrow.