This little Vornado has three power levels, 750, 1150 and 1500. We don't run it all night when boondocking, usually just the furnace in the morning to warm things up. I haven't seen any voltage before sunrise - just the back of my eyelids!! We did run it all night last night but we've got hook ups here. It's 38 out right now and we ran it on low all night, woke up to 65. It's very quiet. Mike