iPad Air charges to 97% despite 80% charging limit

Despite setting a charging limit, you iPad will by design occasionally fully (or near fully) charge the battery - this being necessary to both maintain optimum battery performance and periodically recalibrate the charging algorithm.

While the option to a set a charging limit is available to newer models of iPad, independent studies have shown that for an iPad that is in regular usage, there is very little if any benefit in restricting charging below 100%. For devices in regular use, limiting charging to 80% simply shortens battery autonomy before the device must be recharged or used while connected to external power.

Limiting battery charge to just 80% is beneficial where an iPad is infrequently used for long periods - such as setting aside the iPad, unused, for many days or weeks at a time.

Storing a Li-ion battery at 100% charge for extended periods can be detrimental to long-term battery health - potentially reducing the health and performance of the battery over its operational lifetime. For iPad's in regular use, the difference in battery lifespan has been demonstrated to negligible - any recordable performance differences being within the margin of measurement error and inherent differences between individual batteries.

What will significantly shorten the lifespan of a Li-ion battery is allowing a nearly discharged battery to remain in this state unnecessarily - or setting aside a fully battery for any length of time. In this state the battery can enter a state of deep-discharge, this being a condition from which the battery may never recover. Always recharge your iPad battery when low; never set aside, without recharging, if the iPad shuts-down due to low battery.

In summary, what you see is unlikely to be a fault with your iPad. If you have any concerns whatsoever, you would be well advised to seek assistance directly from Apple Support - and request a remote diagnostic test of your iPad. 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 using the excellent Apple Support App. If not already installed on your iPad, 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. If a fault is identified, you'll be in the best possible place to explore your available options:

Genius Bar Reservation and Apple Support Options - Apple

It doesn't always limit to 80% and charges to even 100% occasionally and it's mentioned in the ipad user guide.

I’ve been trading stuff about charging to 80%. Recent studies show charging to 80% does not help with making the battery last longer. Besides by the time your iPad needs a new battery it is so old a new iPad is warranted.

There is a perception, unsupported by any evidence, that limiting to 80% charge will extend the useful life of your battery. Apple provided this “feature” to satisfy users who have read that charging to 100% will shorten the life of a battery. This is untrue, with only a couple of exceptions: Devices LEFT AT 100% for extended periods of time might have a small effect. And EV cars tell you not to charge above 80% for routine driving, only charging to 100% for long trips. Even here the reason is more that charging above 80% is much slower and thus energy inefficient.

Good explanation.

I’m going to take a screenshot shot of your post and repost it over at the Water Cooler.