Super Long Time for diffusing the oil can last above 48 hours for add water once diffuse the essential oil with the flowing waterhumidify the dry air a little and will not add too much moisture to the airadding ambiance to your living room, office, bedroom, or anywhere you need to add a relaxing touch. the flowing water can add some negative ion and energy to the environment7 changing colors lights The night light create a relaxing & comfortable atmosphere that is good for sleepthe product is made with BPA free and food grade materialcan work seperately without connecting to the power. When the battery is fully charged, it can work for more than 15 hours. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin