The X-Core controller has a mode that no longer requires the battery tab. The controller instead goes into a hibernation mode after 30 seconds. The screen will reactivate after you press and hold the plus button for 10 seconds. The controller in hibernation mode with no AC connected to the controller will hold Date/Time for approx. 5 years.
CAUTION: RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE. DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS.