Why is my iPhone 16's battery health dropping rapidly after 260 cycle charges?

Your battery is doing much much better than average. The battery in the iPhone 16 is designed to go up to 1,000 Charge Cycles before the Maximum Capacity of the battery declines to 80%.

In general, on average, that works out to a normal decline of about 1% for every 50 Charge Cycles. But, the decline will not be consistent. The battery might go a few months without declining at all, then drop 3% the next month and stay there for a few more months before it declines further.

Remember, batteries are chemical devices. They can vary.

At 260 Charge Cycles, the Maximum Capacity would normally be in the 94-95% range. If your battery is really now at 97%, it is doing great. You might consider sending flowers to Apple.

The battery in my phone is right at 300 Charge Cycles and the Maximum Capacity is 94%.....just as expected. I wish my luck was as good as yours, but my products tend to be average.......not exceptional.

Don't worry about the battery. Replace it when it is down to 80% Maximum Capacity. You will drive yourself crazy if you are checking the battery all the time.

That is excellent and doing far better than average! If you end up over 1000 charge cycles before the battery health reaches 80%, it is even better than Apple's expectations.