iPhone 80% Charge Limit: Three Years, 97% Capacity

MacRumors has published a three-year experiment on Apple's 80 percent charge limit for iPhones, a feature introduced in 2023 to extend battery lifespan by charging to 80 percent instead of 100 percent. The site's writer tested the setting on three consecutive Pro Max models: the iPhone 15 Pro Max, iPhone 16 Pro Max, and iPhone 17 Pro Max.

After 12 months with the 80 percent limit, the iPhone 17 Pro Max reported 97 percent maximum battery capacity and 277 charge cycles. That's the best result of the three. The iPhone 16 Pro Max and iPhone 15 Pro Max each ended their first year at 94 percent capacity, the report says.

The writer also tracked longer-term data on older devices. After two years, the iPhone 16 Pro Max lost just one percentage point of capacity from year one to year two, and the iPhone 15 Pro Max lost none. Both phones saw very few additional cycles (44 and 17, respectively) but held their charge while sitting idle.

During the year with the iPhone 17 Pro Max, the writer avoided letting the battery drop below 20 percent and tried to use USB-C charging over MagSafe or Qi2. The report notes that the iPhone 17 Pro Max has a larger battery and faster charging than its predecessor, which made the 80 percent limit easier to live with. The writer still carried a battery pack but rarely ran out of power.

MacRumors suggests that the most hands-off approach is Apple's Optimized Battery Charging, which charges to 100 percent but minimizes time spent there. The 80 percent limit remains an option, and Apple also offers 90 and 95 percent limits for users who want a compromise. The writer already set the iPhone 18 Pro Max to 80 percent and plans to report again next year.

• Apple
• battery health
• charge limit
• iPhone
• MacRumors