Hi, that red X on the battery, hasn't to do anything with the Device it self.
I also had first a red X with a car charger, so I read the manual. The car charger has to be from Samsung it self, or it has to be approved by Samsung. Using a other charger, can damage the device or it will even turn out in explosion, don't take the explosion thing to serious, but it does stand in the manual. So buy a Samsung car charger, or a approved one. Read the manual yourself if you want to be sure. You can also contact Samsung it self.
Hope this helped, have a nice day.