This diffuser works very well and looks really nice. I like the way that it lights up and doubles as a night light which is great, It fills my room with a nice aroma of whichever oil I add to the water, Most of the time I leave it plugged in and run it, but I have let it run off of the battery and it lasts a good 7 to 8 hours on the intermittent setting.  So far I have nothing but good things to say about this product.  I plan to buy another one for my daughter's room.