How to fix 'Unverified Battery' and 'Unknown Part' error after iOS 26.2.1 update on iPhone 11?

Kindly reach out to the Store/Individual/Agency from whom you acquired your iPhone. They would be best equipped to confirm whether the device has undergone servicing by an unauthorized service provider.

In case you recall not encountering this message at the time of purchase and it surfaced after an update, it's important to note that this message is visible specifically on iOS 15.2 and subsequent versions. It might be beneficial to inquire about any recent updates or changes made to the device's software configuration that could have triggered this notification.

Understanding the circumstances surrounding the appearance of this message could provide insights into any alterations in the device's service history or software updates that have brought about this notice.

Camera and service history

With iPhone 12 models and later using iOS 15.2 and later you can go to Settings > General > About to see the parts and service history of your iPhone and you can see if the camera has been replaced. If the repair was done using genuine Apple parts and processes, you will see "Genuine Apple Part" next to the Camera.

• You will see an Unknown Part  message if the camera installation is incomplete or if the camera:
• Was replaced with a nongenuine camera
• Was already used or installed in another iPhone
• Isn't functioning as expected

This message doesn't affect your ability to use your iPhone or access your camera.

Learn more about iPhone parts and service history.

Battery and Display and service history

With iPhone 11 models and later, excluding iPhone SE (2nd and 3rd generation), using iOS 15.2 and later, you can go to Settings > General > About for the parts and service history of your iPhone. You can also find out if the display has been replaced. If the repair was done using genuine Apple parts and processes, "Genuine Apple Part" will appear next to Display.

• An Unknown Part  message will appear if the display installation is incomplete or if the display:
• Was replaced with a nongenuine display
• Was already used or installed in another iPhone
• Isn't functioning as expected

An additional message might appear that says "Apple has updated the device information for this iPhone." This means that Apple has updated the device information maintained for this iPhone for service needs, safety analysis, and to improve future products. 

If your iPhone's parts have been previously replaced, repaired, or serviced by an unauthorized service provider, it's worth noting that Apple may decline to provide service for your device. The decision to refuse service will depend on the specific components that were affected by the unauthorized service.

Get a Genius Bar Reservation and Apple Support Options - Apple

Contact Genius Bar.

Manage Reservations - My Reservations - Apple

Unverified Battery' and 'Unknown Part' errors are not caused by iOS 26.2.1  . Many things can cause phone problems.  If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.

Remember, the right question often leads to the solution!

Was/Is your device Jailbroken? If that's the situation, please be informed that attributing the issues to iOS updates may not be accurate.

iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. The majority of the issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.

Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.

Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.

See what each update does: OS — iOS 26, About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...