Why does my iPad Pro charge to 100% when I set it to 80%?

While the optimised charging limit has been available for iPhone for some time, this feature is relatively new to iPad - and is only available to newer models of iPad that have been since released.

Optimised charging (that limits routine battery charging to ~80%) is only available for iPad Pro M4, iPad Air M2, iPad mini A17 Pro. That said, be aware that iPad has always actively managed battery charging, automatically altering the charging strategy where an iPad is connected to an external power source for extended periods.

When used in kiosk applications - where external power is connected for extended periods of time - the iPad may modify its charging strategy and limit battery charge to ~80% of maximum. This modified charging strategy is designed to reduce chemical ageing that might otherwise occur if 100% charge is maintained at all times.

Nominal 100% charging will be restored when a normal charge/discharge routine is restored.

More information about iPad’s battery management can be found here:

About iPad and iPhone Charge Management Feature – Apple Support

It is entirely normal for your iPad to occasionally fully charge the battery to 100% having set the charging limit to 80%. This is required to both calibrate the charging process - and maintain optimum battery health.

Your reply brings up another question. While on my iPhone 16 Pro I set the charging limit to 90% (which gives me two full days of use). However, on my iPad Pro 12.9" 6th generation, I do not see the option for setting the charge limit. Is this only available on the latest and greatest iPad... and not my antique (haha) from last year?