Battery Health Dropped from 99% to 98% in Just a Few Days – iPad Air M3

Your iPad battery is rated to retain 80% of its original maximum capacity (when new) after 2000 full battery charge cycles - a full charge cycle being defined as any combination of charging that together sums to 100% (e.g. 40 + 20 + 20 + 15 + 5 = 100 = 1 full cycle).

Simple math, assuming battery health will drop in a linear manner, suggests that you can expect to see the indicated battery health to fall by 1% for every 50 full charge cycles. As the indication in rounded-down to an integer value, a calculated battery health of 98.999% will be expressed as 98%.

With this in mind, your indicated battery health is entirely within the expected range for your described usage.

If you have any concerns whatsoever, you would be well advised seek assistance directly from Apple Support - and request a remote diagnostic test. You can contact the Support Team using the Support link at top-right or bottom-left of this page.

Alternatively, you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:

https://apps.apple.com/app/apple-support/id1130498044

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:

Genius Bar Reservation and Apple Sup

Nothing to be concerned about. The drop you see will not be linear so some months will not drop at all and other months you may see a larger drop. Also note that calibration only occurs when the iPad is allowed to charge to 100% and that will happen automatically on occasion, even with a charge limit, to perform the calibration as long as you to not remove it from the charge while it is attempting to charge to 100%.