Ioniq Hybrid Alarm System Issue

I also own a Hyundai Ioniq Hybrid, and your issue sounds familiar. If the error message mentions a low voltage or battery signal from the alarm system, the backup battery for the alarm system could be failing. These batteries power the alarm if the main car battery fails. This happened to me some years ago, have you checked the voltage of the car battery?

The error message mentions a low battery signal related to the alarm system. Could a weak car battery cause the alarm system's backup battery to fail prematurely, or are they independent?

They are reasonably independent. A degraded main car battery can cause unusual electrical behavior in auxiliary systems, especially during starting. But, given the error mentions the alarm system battery, and your vehicle's mileage, the alarm system backup battery is likely nearing its end. Have a workshop perform a diagnostic check to confirm before replacing parts. I went directly to the workshop when I experienced this.

I had the car diagnosed at a local workshop, and the additional battery alarm system was defective due to an aging battery. The replacement cost, including labor, came to 330€. Your comments saved me time and worry!