I have been taking apart some of our old PCs and cannibalizing them together to get some computer experience in while I have nothing better to do, and I noticed that most of the cooling fans I have seen use the red and black ends on an RWB cable. I mounted one on my bot like this, and it runs perfectly. I checked the specs on the fan I am using, and it only draws .12 Amps. possible uses would be something like a cleaning bot or even just to keep the battery cool.
if you can fin the fan online (if they still sellem) get 5 or so so you have 1 for battery and 5 to use on motors and such
they sell them at Staples, and with cool LEDs too!
http://www.staples.com/office/supplies/p1_Cooling-Fans_207016_Business_Supplies_10051_SEARCH
I have answered the questions on the image page about the fan, if you posted there, check it out. Sorry for not replying to any of the posts on the image page before now; I hadn’t checked it.
Here’s something that would be better for a cleaning bot. I don’t think this particular thing is even made anymore though, as I pulled it off a Win 95 Gateway. It probably wouldn’t be hard to find something equivalent though. The big plastic part was covering the Motherboard cooling fins.