MY Cloud EX2 Ultra / Eaton S3 USV /automatic shutdown


I’ve just a short question; I bought a Eaton S3 USV for my EX2 Ultra and connected it via the USB Cabel.
The USV was recognized and shown on the dashboard under the UBS Sign. I tested it (disconnected it from the powernet) and the EX2 recognized the Battery power supply (LED red blinking / E-Mail with notification) I didn’t wait until the battery was empty. My question: Will the EX2 automaticly shut down BEFORE the battery power is empty (Didn*t tried this yet)?
With kind regards