I wrote cyber power on this unit, and they gave a nice explanation on how to mute the device. Problem is, there is no mute. So you sit there, with a light on listening to beep beep beep over and over till it drives you nuts. I used it for the first time last night when the power went out. It was so aggravating I turned it off, and used a candle. Candles.. the old fashion way is the best alternative, rather then paying out 150 -200 dollars for these useless noisy units. WHY would cyber power even put a loud beeping noise on this thing while your sitting in the house trying to read at least while there is no power is beyond me. The most stupid option you could ever come up with, it reminds you how much electricity is left, so its basically a count down. Unlike the candle that lasts much longer for light in the house, this thing lasts a hour or so. What a bloody waste of money. I bought another unit off them also, for the computer. Watched some hour show and it ended with this other one shutting down. I sat in the dark thinking some big shot at cyber power is smoking a cigar on my 300 bucks I just wasted for noisy devices. DON'T WASTE YOUR MONEY... Get a cheap alternative. Technology for this is not good enough. These days they should have something that lasts more then 2 hours. Flashlights, lamps on battery, and the good old candle work fine, invest in something smarter, and less noisy. I unplugged both of these now, and prefer silence to noise.