DEJI high capacity battery for iPhone 15 Pro Max Capacity: 4422 mAh   Note: If you replace the battery while you have iOS 17.4 installed on your device, the battery health status will not be updated. This is because Apple's IOS system has a bug on this version, so it is fixed in the new version of IOS. If you replace the battery under other versions of IOS (except version 17.4), the above problem will not occur and it can be used normally with updated battery health status. Solution: If you currently have the installed version of the system IOS 17.4, before replacing the battery you should update to a newer version of the system. At the time of writing the current version of the system IOS is 17.5.1. If you currently have a version of the system installed that was released before IOS 17.4, then you will not have any problems. You can freely update the IOS to the latest version after replacing the battery.   Instructions: -Remove the flat from the old battery and attach it to the connector from the new battery -Fleш via 3Tools for iOS on 17.5.1 -Check battery health