A.Does the desk fan have a rechargeable battery? Does this have to be plugged into a usb to use it?
The mini desk fan without battery, you need to plug the USB cable comes with the fan to use it.
B.If I have a portable charger for phones could I use this on the fan?
You can plug this Mini USB Fan to any USB ports on laptop/PC, power bank, phone adaptor to a wall strip etc.
C.If I unplug it while its on, when I plug it back in will it turn on automstically without pressing the power again?
No. It will not.You must press the power button again to turn it on and select one of the 3 speeds you need.
D.Is the 360 degree angle easy to adjust?
Yes,very simple.Only need to turn up and down,and then you can enjoy any angle wind you want.
E.Does the cable detach / unplug from fan?
No,it doesnt.This will prevent the power cable from being lost.