Just looking at the installers manual for the R8 now, it doesn't mention a backup battery other than the main one so I don't think the NVM requires one.
However, it does mention that if you've lost the engineers code, you can reset the panel to factory defaults. This involves disconnecting all power, re-applying it followed by a button press within 10 seconds, having read the detail, it's entirely possible you reset it yourself without knowing what you were doing.
And before anyone suggests this is bad practice or immoral, this information is available publicly via a google search so I'm not putting anything out there that bad types can't already find (worst of all, it's being hosted by an alarm company).
However, it does mention that if you've lost the engineers code, you can reset the panel to factory defaults. This involves disconnecting all power, re-applying it followed by a button press within 10 seconds, having read the detail, it's entirely possible you reset it yourself without knowing what you were doing.
And before anyone suggests this is bad practice or immoral, this information is available publicly via a google search so I'm not putting anything out there that bad types can't already find (worst of all, it's being hosted by an alarm company).