You can check your iPad's battery health by following these steps:
Open the Settings app on your iPad.
Tap on "Battery" in the left-hand menu.
Tap on "Battery Health" in the right-hand menu.
You will see a section titled "Maximum Capacity" which will show the current maximum capacity of your iPad's battery. This number represents how much charge your battery can hold relative to when it was new. Ideally, this number should be close to 100%.
Below the "Maximum Capacity" section, you will see a section titled "Peak Performance Capability". This will indicate whether or not your iPad's battery is currently able to deliver peak performance. If this section says "Your battery is currently supporting normal peak performance," then your battery is functioning properly. If it says "This iPad has experienced an unexpected shutdown because the battery was unable to deliver the necessary peak power. Performance management has been applied to help prevent this from happening again," then your battery may be degraded and in need of replacement.
If you have an older iPad or one that has been heavily used, it's normal for the battery capacity to decrease over time. If you notice that your battery is significantly degraded or you're experiencing unexpected shutdowns, you may want to consider getting the battery replaced by an Apple authorized service provider