battery health

Well, that battery is reaching the critical point of its life (80%) and could have unpredictable behavior.

I suggest that you create a full backup of your iPhone on a regular basis (at least once a week) to avoid surprises.

Using this link, you can get an estimate for battery replacement of your unidentified model (after selecting your country:-->Choose Your Country or Region - Apple Support

Then, just to be sure that your specific model's battery is in stock, I recommend that you make an appointment (*) and have your battery replaced at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> https://locate.apple.com/choose-country-region .

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.

Absolutely normal.

Bear in mind that that value is approximate (it could be 99.9%) and, most of all, that it is related to when the battery (not the iPhone) was new. Start worrying when that percentage goes down to 83-80.

Seeing your screenshot, I suggest that you never let the battery level go down below 20% (when possible).

See also this useful user tip:--> When to charge your iPhone or iPad - Apple Community

Regards

Giulio

This may help --> Prolong and Maximise Battery Performance … - Apple Community

My battery health is at 83%, does it need to be replaced?