I was afraid to finish but I am rather reassured. 15 days that I use, alkaline batteries seem to hold and the clock does not disrupt. The light / dark sensor is very sensitive: the screen is slightly illuminated in the darkness and lighting switches off any ambient light. Personally, I activate this dark sensor (sensor button on / off) at bedtime to save batteries. If your room is still in the dark during the day and if you do not use it, it is better off in the morning. The touch button on the top is used for powerful lighting for a few seconds (I never use myself) or to stop the alarm. This button is not always very responsive but responds better when using 2 fingers. A smaller unit would still have been better (I put it vertically to save space as is 15cm wide). My model also has a connector for connecting an AC adapter, but never tested.
