iPhone 11 iOS 16 3 battery 81%

Batteries will wear out over time. Updating to iOS 16.3 will not change your battery health. If your battery health shows 81%, then it is soon time to change the battery.

More info about battery usage:

About the battery usage on your iPhone, iPad, and iPod touch - Apple Support

More info on iPhone Battery and Performance:

iPhone Battery and Performance - Apple Support

If your iPhone needs a new battery, look here:

iPhone Battery Repair & Replacement - Apple Support

Apple recommends replacing the battery at 80%. That is not a hard and fast rule, you can probably stretch things for a few more months and get down to 77-78% without noticing much difference in battery performance

The point here is that there is a battery replacement coming in the near future. It is important that a genuine Apple battery is installed. That's why we advised to have the Apple Store or an authorized Apple Service shop perform the service. Other shops do not have access to genuine Apple batteries or other parts.

Battery replacement is about $70 U.S.

Ignore the articles. The first two links are just info if you were more curious about your iPhone's battery. As Bob Timmons writes, update to iOS 16.3 if you want the latest update with bug fixes. However, this will not change the state of the battery.

As we both wrote, if your iPhone's battery health is at 81% - then the battery needs to be changed soon if you want to keep a usable battery life.

If you want to have your battery replaced, start here:

iPhone Battery Repair & Replacement - Apple Support

The battery needs to be replaced at the Apple Store or authorized Apple Service shop when the phone is down to 80% Battery Health / Maximum Capacity.

Update to iOS 16.3 if you want the latest bug fixes and security updates.