Emerson Research SMARTSET CKD5809C Owner's Manual page 7

Installing The Sure-Alarm Back-up Battery (Not Included)
The Sure-Alarm battery compartment is located on the back panel.
1.) Press down on the battery door locking tab as
shown and remove the battery door.
2.) Gently pull the battery terminal outside
of the compartment just far enough so
you can connect the battery.
3.) Connect a fresh, well-known brand of
9-Volt Alkaline battery to the battery
terminal. It can only be connected one
way.
4.) Push the battery back into the battery compartment and replace the battery
door.
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