I've been using my iPhone 12 Pro Max for just over three years ... involved a bit of intentional waiting for my iPhone's battery capacity to degrade under 80% of its maximum capacity.

Fans hopeful for a high-capacity battery were disappointed by the ... Our testing revealed that charging a drained iPhone 12 Pro Max to 53% took about two hours. It produced very little heat ...

For instance, one user who set an 80% charge limit on their iPhone 15 Pro Max for a year observed that after 493 charge cycles, the battery retained an impressive 87% of its original capacity.