Since 2023, Apple’s newer iPhones have had an 80 percent charge limit intended to extend battery lifespan. I used that setting for three years on successive Pro Max models — I started with the iPhone 15 Pro Max, then the iPhone 16 Pro Max, and most recently the iPhone 17 Pro Max — and here are the measured results.
After 12 months at an 80 percent maximum charge, my iPhone 17 Pro Max is at 97 percent maximum capacity with a cycle count of 277. Last year, my iPhone 16 Pro Max was at 94 percent capacity after 12 months, and in 2024 my iPhone 15 Pro Max was also at 94 percent capacity after its first year.
iPhone 80% charge limit: measured capacities and cycles
Over longer periods, the devices show the following battery-health figures while kept at the 80 percent limit:
iPhone 15 Pro Max (36 months) — 88%, 369 cycles
iPhone 16 Pro Max (24 months) — 93%, 343 cycles
iPhone 17 Pro Max (12 months) — 97%, 277 cycles
During the year I tested the iPhone 16 Pro Max I tried not to let the battery dip below 20 percent. This year I did the same and also tried to charge more over USB-C than over Qi2 or MagSafe; I am not sure if that helped, but 97 percent capacity is the best result I have had so far with the charge limit enabled.
Apple transitioned to aluminum and added vapor chamber cooling with the iPhone 17 Pro Max; I observed that the 17 Pro Max spent less time uncomfortably warm than the iPhone 16 Pro Max, and it may be that the vapor chamber cooling made the biggest difference and limiting wireless charging didn’t matter.
The iPhone 17 Pro Max has a bigger battery and faster charging than the iPhone 16 Pro Max, so an 80 percent charge limit was easier to live with. I rarely ran out of battery, though I still brought a battery pack most places. My favorite battery packs are those with built-in USB-C cables, especially ones that attach magnetically but charge over USB-C, and I also like super-slim battery packs that add little bulk.
For the iPhone 15 Pro Max and iPhone 16 Pro Max, I didn’t think sacrificing a fifth of my battery was worth the capacity I ended up with, and that’s still mostly the case. I’m guessing my 97 percent capacity isn’t far off from the battery-health readings on iPhones that didn’t have the charge limit turned on.
As for older devices, my two-year-old iPhone 16 Pro Max lost only 1 percent capacity from 2025 to 2026, and my iPhone 15 Pro Max didn’t lose any capacity during that year. Both phones had fewer battery cycles (44 and 17, respectively) but are holding capacity even after sitting dead for short periods throughout the year.
The most hands-off way to manage battery health is to use Optimized Battery Charging, since it minimizes time spent at 100 percent while still charging to full. Setting an 80 percent limit and then turning it off on days you need 100 percent is a workable compromise that could save capacity over time; Apple also offers 90 and 95 percent options.
My iPhone 18 Pro Max is already set to 80 percent, and I’ll check in again in September 2027. I’ll stick with USB-C charging when I can, and I’m curious how the even bigger battery will affect longevity and what the 80 percent limit is like day to day.
What’s your iPhone battery capacity and cycle count? Share it in the comments below and weigh in on whether you think battery charge limits are worthwhile.
