iPhone Battery icon is now half shaded

It's not a phone issue, it is how it is designed and I see the same thing on mine.

A little history if my memory is correct: when iPhones with the "notch" at the top of the screen were first introduced (iPhone X), there was less space available; before the iPhone X you could display both a battery icon (with shading to indicate charge level) and a battery % beside it. The option to display the % was removed when the iPhone X was released as there wasn't space for it. Numerous complaints followed, asking for the % back. When iOS 16 was released, you could display the % numbers inside the battery icon but if you did, you didn't also get the shading (i.e., numbers OR shading). When 16.1 was released, if you elected to display the numbers it was on top of the shading (i.e., numbers with shading OR no numbers with shading).

I have an opinion about what the best option would be -- but it doesn't matter.

Tricknsensp ~ You may like Apple's "Batteries" widget on your Home Screen:

Use widgets on your iPhone and iPod touch

õ¿õ¬

That was a change made in iOS16.1 -- the battery icon now visually shows the battery level by the shading in the icon (like it did in iOS 15 and earlier) along with the option to also display or not display the percentage.