IPad mini keeps turning off even when battery status is at 50 percent. Does it need replacement battery?

You might be well advised to seek assistance directly from Apple Support - and request a remote battery diagnostic. Alternatively, if you take your iPad along to the Genius Bar at your local Apple Store, the technicians will be able to test and assess your iPad.

You’ll find the Contact Support link at top-right of this page. You can also initiate contact, or raise a support case, 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/gb/app/apple-support/id1130498044

Always happy to share the benefit of knowledge with those receptive to it. 🙂

The Apple Support App has been available for many years - and provides a direct gateway into help and many support services. The App is frequently updated.

For iOS/iPadOS13 and later, if the Apple Support App is not already installed, there is also a direct link to it from Settings:

Settings > General > About > [ ... Coverage ...] > [Get Repair or Support] Get Apple Support App

Once the Apple Support App is installed, the dynamic link updates to the the Support App itself.

I just learned something else new today!

Never knew about this app ever!

Downloading now, myself!

If you contact Apple directly by phone, they can do the battery diagnostic remotely through remote device sharing.