Non-volatile memory is a feature on all Hunter controllers, back up memory is stored with the assistance of a lithium battery installed inside the controller. This lithium battery is replaceable on these model controllers:
On all other Hunter controllers the lithium battery is afixed inside the controller's internal components and cannot be replaced.
Under normal power outage situations the back-up battery should provide power to the memory for the life of the controller. Prolonged demand from the battery will however shorten the life span and accuracy of the back up memory. The back-up memory will only call on the battery when memory needs to be pulled off of the controllers temporary hard drive.