Schlage keyless entry and keypad locks use batteries to control the locking mechanism and store the key codes. Some locks use two sets of batteries, while many use just one set. The lock has an indicator light that flashes when the batteries are low and require replacement. Changing the battery on a Schlage lock does not require re-coding the system. The lock has memory, which keeps the code intact when changing batteries.
Remove the screws securing the cover on the inside of the door with a Phillips-head screwdriver. Grasp the cover by its sides and pull the cover from the door.
Find the screws that secure the battery cover to the lock mechanism. Depending on the model you have, there is either one or two square battery covers. Remove the screws and pull the battery covers from the lock mechanism.
Pull out the AAA batteries from the lock and install new AAA batteries. If you have a lock with a 9-volt battery, carefully remove the battery from the compartment and disconnect the wire cap from the top of the battery. Install a new battery onto the wire cap and carefully insert the battery back into the compartment.
Place the battery cover back over the battery. Avoid pinching the wires if you have a lock that uses 9-volt batteries. Secure the battery covers with the retaining screws.
Position the lock cover over the mechanism until it is flush against the door. Secure with the retaining screws.