How do I wired a 7.2V fan to 14.8V 4s Lipo

[BrianG]

Using resistors is possible, but it would be much better to use a voltage regulator. The LM317T is an adjustable unit which can be hardwired for whatever voltage you want from 1.25v up to about 1v less than the supply voltage. There are diagrams, pinouts, and formulas on the back of the package if you get it from radioshack.