Reg:-Battery percentage

Your battery is doing just fine.

Batteries degrade over time with usage due to chemical aging, that's just how they work.

You can expect about a 1% drop per month with average use on an iPhone.

Apple recommends replacing it when it reaches 80%. To check your battery health, go to Settings > Battery > Battery Health.

iPhone Battery Replacement.

iPhone Battery Repair & Replacement - Apple Support

About Lithium Ion Batteries

iPhone Battery and Performance - Apple Support (IN)

Here are some tips on maximizing battery life.

Batteries - Maximizing Performance - Apple Batteries - Maximizing Performance - Apple

Apple say, it’s, gonna replace your battery, when it’s come down to 80% within 1year.

unless they won’t.

and for, as of now, battery health, totally depends on your usage,

+ iPhone 11 processor is already old 2019, and it’s dealing with 2023’s apps, so it’s consume more power then usual.