Bad battery on iPhone X?

You should see your local Apple Store about this, I'm sure they will replace it for free.

When did this happen? If you have plugged in any iPhone Accessories into the Lightning port, that may be the cause of this, for example, there is a Fan which you plug into your lightning port, and it completely kills the battery.

But as I say, see an Apple Store.

Good Luck.

Hi

Sounds like a faulty battery make an appointment at Apple store For checking.

Or go to Support.apple.com.

If you purchased from a network provider return iPhone to them.

Cheers

Brian

🇬-1F1E7;