New iPhone 16 not showing battery health

Please try a forced restart of your iPhone.

Force restart iPhone - Apple Support

1. Press and quickly release the volume up button.
2. Press and quickly release the volume down button.
3. Press and hold the side button. Do not swipe the off button.
4. When the Apple logo appears, release the side button. It may take as long as 30 seconds for Apple logo to appear.

The iPhone battery should be serviced or recycled by Apple or an Apple Authorized Service Provider. See the Battery Service and Recycling website.

Go to Settings > Battery, then tap Battery Health & Charging. iPhone displays information about your battery's capacity, peak performance, and whether your ...

Check the iPhone battery health and usage

Purchase Apple Products from the Apple Online Store, Apple Retail Stores, and many Apple-authorized resellers and wireless service providers.