Getting battery health information of attached iOS device from macOS

Quick one, mostly for my own memory. I’ve wanted to find the battery health of attached iOS and iPadOS devices from a Mac, and today I figured out how.

Install libimobiledevice first, probably with brew install libimobiledevice.

Then, run idevicediagnostics ioregentry AppleSmartBattery with a device attached.

Apparently the iPhone 7 and below will use idevicediagnostics ioregentry AppleARMPMUCharger instead.

The data comes back as a plist by default. The health information you’re looking for is likely AppleRawMaxCapacity for the full charge capacity and DesignCapacity for the original capacity. Divide AppleRawMaxCapacity by DesignCapacity and you have the device’s battery health.

This might help as people try to figure out how the iOS Battery Health meter determines the health of the battery. The calculation is obviously not as simple as AppleRawMaxCapacity/DesignCapacity since it will list 100% health at far below that number in raw mAh. Maybe Apple wrote the algorithm to take battery cycles into account, for example if the raw capacity is 80% and there have been 500 battery cycles the health is 100%?

Not sure, but now we know how to get the info.

Thanks to https://github.com/libimobiledevice/libimobiledevice/issues/1095 for finally unearthing this information after weeks of searching.