The Stone of Azrael

The Stone of Azrael dictates what is a monster and what is not. The stone talks to you, or does he have like a beep system. If it's tracking monsters in the area, then that's going to eat them whole time. It takes a while to figure out because sure there were some random beeps at first. These things sort of happen and sometimes it's really hard to read. For instance, when an evil specter came and killed my wife and child and carried them into the abyss, I was really upset that the stone didn't do anything. But I hadn't charged it. Is the battery last third of the day? What depends how much you use it