Help With Electronics Project

What I want to do I want to take an RC 3S lipo battery and turn it into a USB power bank so is what I need to do is step the voltage down from 12v(Lipo) to 5v USB I was given a Mosfet from a friend he said would do it with a heat sink. But I'm pretty new to electronics so how would I set this up so I can charge the Lipo with the Wall Balance charger use it as a High Ampage USB charger but then also have it cut power when voltage drops to a certain point and what all would I need?

So I have:

Arduino Uno Bread Board LM338T 3x Aluminum Heat Sinks Hundreds of LEDs and Jumper wires and a 3S 30C Lipo Battery

How quickly can you get a degree in Electrical Engineering ?

Hi,

http://www.ti.com/lit/ds/symlink/lm338.pdf

How quickly can you get a degree in Electrical Engineering ?

I think your mate ought to as well.

LM338 is not a MOSFET.

I think you need to learn some electrical/electronics basics before attempting this project.

Tom.... :)