Defaulting - restoring to factory settings and codes
Unlocking - so defaulting can be achieved , if locked you have mess around to unlock on many panels and some never will
Mostly the defaulting procedure is done incorrectly lol
Ah quick read thought You said cr123 pretty standard which reality is , it isn't
But yes no one said it's a door contact , and yes stupid array of batteries
Customers buy those dial batteries or whatever they are called and expect them to last lol