Can i leave a usb fan on over night?

Can i leave a usb mini fan on over night but not plugged in to the computer instead a iphone 5 plug

Added (1). I don't mean a motherboard fan i mean http://www.wilko.com/fans/beldray-fan-mini-usb/invt/0332344

Yes for sure i tried it and it was cool but if you didn't found the one that you was searching for you will do as me… Make your own hehe

Thats good init

You can leave it in, depending on the motherboard, it might still run after the pc has been turned off, but it won't take damage from it.