Regarding the question of whether the Stream 94i EU Plus can be operated with batteries: I have looked very carefully at this model but have not found the slightest indication of a battery compartment. However, the instructions for the previous model on page 2 state: Mains or battery operation via the supplied mains adapter or optional rechargeable battery (not included).
If a "battery" is mentioned in some comments, it is always the battery of the associated remote control.
Mobile greetings to all listeners! thomi.