I have bought 2 of the reception so I experimented with usb and 4 Duracell batteries with new LR06 new home !! I could costater is that the fans was not reliable (have not esting the air 60cm / 70cm with tests with smoke !!) last week I purchased another fan on the site the same identical model except no mark on the base !! it works very well indeed I was a command on and go back the other 2 ventilos !! can be a bad series !! more flexible is very rigid, were afraid to break everything !!! a wise hello !! more technician and I am very good handyman