I have a new Cannon safe with keypad. I know it says it will beep when the battery is low but to be honest i'm tone deaf and cant hear beeps very well, in fact when we were resetting the code, I couldn't hear it beep at all. So I'm planning on just changing it out every 6 months. Think thats too much? I figure better safe that sorry, five bucks a year isn't going to break me. Or am I way off and need to change it more often?