The batteries will last for quite a while but eventually need to be replaced. Replacing them is quick and easy.
Remove the Allen screw on the door handle with the Allen key and set the handle aside.
Remove the metal shroud by pulling it. Notice that the black bearing will also fall off.
Remove the plastic cover.
Replace all 8 batteries. Ensure that the negative pole of the battery (- / flat side) is touching the spring.
push the plastic cover back onto the Motor Module.
Put the metal shroud back over the enclosure.
Slide the black bearing back onto the axle.
Place the handle back and tighten the screw.
ATTENTION: Do not over-tighten the screw! It is unnecessary, and the screw will likely get damaged.
The first time you use the lock, it will automatically calibrate and find the position of the lock.