I understand the Open Sesame systems use a battery. Do they need to be changed frequently?

No. The door operator contains a single 12v, 1.2 Amp-hour sealed lead acid battery. This is what actually runs the system. This type is used in alarm systems. It should last at least 3 years. Some symptoms of needing a new battery are: the door opens and closes slow, the door may start occasionally, failing to open or close, or the clutch stays engaged after closing making the door hard to open manually. The remote control batteries are the type that can be found at a WalMart or a drug store. They should be replaced once a year.