iPhone 16 Pro Max battery health percentage decreasing rapidly

Expect your Maximum Capacity to decline about 1% for every 50 Charge Cycles.

If your phone is at 250 Charge Cycles, your battery should be at 95%.

You should send flowers to Apple. Other users are wishing that their luck was as good as yours.

This tells me that your battery was really at 104-105% when it was new, although Apple would still still display that as 100%. But, the averages are now starting to catch up for you and things will act more normal going forward.

At 350 Cycles, your battery should be at about 93%. At 500 Cycles, it should be at 90%.

Send more flowers to Apple if your battery is above these averages at the time.

Make sure you are not micro managing the charging of your battery. Some users will prevent it from ever charging to 100% and that is required for it to calibrate. Those users see a larger drop because the battery had not had a chance to calibrate previously and when it was able to calibrate, the actual Battery Health was able to be updated.

Even when using the 80% limit, the iPhone will charge to 100% occasionally in order to perform this calibration. That is normal. Your battery is doing great by the way, so you have nothing to worry about. Enjoy your phone, as it is doing much better than average and should be closer to 95%.

Well yes. Once my iPhone dropped below 100% the battery health started to decline very fast. But it will plateau at some point. So I’d expect the battery health to decline rapidly for a little bit!