iPhone 17 battery maximum capacity at 91% after one year

Months don't matter. Charge Cycles do.

Someone could own a phone for 10 months and not use the phone that much. Another user could own a phone for 10 months and use it heavily. The Maximum Capacity would be completely different for these two users.

We need to know how many Charge Cycles the phone has completed to be able to answer your question.

sharvari227 wrote:

I bought my iPhone 17 in September 2025 and now as of September 1st 2026, my battery maximum capacity is at 91%

Is this considered to be good or bad? How should I maintain my battery’s maximum capacity?

Without knowing the number of Cycle Charges, it's hard to know how your battery is doing. Read this and it may help you --> Battery Health Decline - Should You Worry… - Apple Community

The following was included in the original response, but somehow did not appear:

Ideally, you would see that your battery has completed about 450 Charging Cycles at this time.