SendaiBoy 4 Works wonderfully as a motion light for our dark genkan and for wandering into the kitchen at night. The battery seems to last for about a week in such situations.The only real complaint is it is very insensitive to ambient light. This is fine for the genkan which is normally very dark and lightly travelled. But in the kitchen, it has to be very bright - usually the main overhead light at full power - before this thing will not turn on due to motion.