to power computer fans, you can use any power supply that puts out between 200ma-400ma (miliamp) anything higher than that, you will risk frying the fan motor. cell plhone chargers tend o be in the 100ma-300ma range, nothing powerful as they only need to charge a phone. If you have an old cordless phone laying around try that. On the plug box its self it will tell you the volts,ma's ect. Just be sure that all positive terminals connect as well as negative, Dont be afraid of crossing lines and frying the fans, if you feed them the wrong power line, then they just wont start, will not do any harm as long as you done exceed the 400ma mark. This is what i have done and if done properly you can wire up numerous fans together but to be safe, i would NOT wire more than 4 to a single power feed! ! ! ! ! , best of luck -----------------------------------420