iPhone 8 crashes unless on charging pad

Richard Hertzberg wrote:

My iPhone 8 worked fine until a few days ago (I recently did an iOS upgrade to 16.7.10 ). Now it goes dark as if battery is dead. If I keep it on the charging pad, it stays on and works normally. If I take it off the pad, the battery shows 90 to 100% charge, but still winks off after a few seconds. I did get one notice of the battery management being faulty and that it was being reconfigured. But that did not help.

The cable cannot be used as its port is faulty so does not connect.

Have you shutdown & restarted the iPhone ie power off/on...if no resolve proceed

Restart your iPhone - Apple Support

Reset or a Force Restart,

Force restart iPhone - Apple Support

Restore from backup, restore as new device.

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

Put your iPhone in diagnostics mode - identify potential hardware and software issues

How to put your iPhone in diagnostics mode - Apple Support

iPhone Repair and Service - Apple Support

iPhone Repair & Service - Apple Support

Check Device Coverage

Check Your Service and Support Coverage - Apple Support

The cable cannot be used as its port is faulty so does not connect.

My immediate thought (without actually knowing the technical details of Lightning ports nor battery management) is that maybe the port itself has a short that is rapidly draining the battery somehow.