I had a spare computer fan laying around along with some other parts, so I decided to make this portable fan.
Step 1: Materials
12v. computer fan
2 9 volt batteries (preferably one good and one dead)
hot glue gun
Step 2: The case
Use a screwdriver and pliers to open the case on the dead 9 volt battery. remove the "guts" and set them aside. now take the connector part of the battery you took apart and solder the positive wire from the fan to the negative terminal and solder another wire to the positive terminal. Now cut a hole for the switch in the side of the battery with the dremel. (use safety glasses)
Step 3: Case cont.
Now put the switch through the hole you made. Solder the negative wire from the fan to one prong on the switch and solder the wire from the battery terminal to the other prong. Hot glue the battery terminals and the bottom of the case back in place inside of the case. Now hot glue the battery shut. Finally, just hot glue the battery to the bottom of the fan.
Step 4: All done!
now just connect the good 9 volt battery and flip the switch. I posted a video below to show me using my fan. I hope you enjoyed this instructable. please rate and comment. thanks for viewing :)