This is the second unit we have had. The first one worked properly for several years requiring annual battery changes. Then it quit and we purchased the same model as a replacement.
We have the lock on the door between the garage and the utility room. We keep the door locked and use it many times a day. Just program an easy to remember number in to the unit's memory and punch it in and you are in. If the batteries go dead, you can use the provided key to gain entry. Batteries are easy to replace and last at least a year of heavy use.