There is battery health data stored on your iPad, but you won't find it in the Battery menu. Here's a couple of ways to check it manually.

Go to Settings > Battery > Battery Health to check the iPad battery health. If your iPad doesn't have that option, ...

Open the Settings app. Tap your name, then tap "Find My." Turn on "Find My [device]" and "Find My network" to locate your device even when it's offline. Make sure ...