I have a Patriot (made by Cannon) gun safe with an electronic lock. About 5 days ago the 9V battery went dead. I replaced it, and then next day it was dead again (replacement battery was suspect). I replaced that with a brand new fresh Duracell. Today it was dead again. Is there something that causes these locks to drain the batteries that fast. The safe is about 3 years old and normal battery replacement was about once every 10 to 12 months. Other than the battery drain, it functions fine.