During the last two decades, Unmanned Aerial Vehicle (UAV) technology has spread quickly to many fields of applications. Wildfire mapping, disaster management but also space exploration are just some of the many fields of application and global awareness about the usage and the power of this device is growing up. One of the biggest issue with a UAV is the battery life especially during a long task where the battery cannot be changed or recharged quickly. For this reason, the efficiency of the powertrain plays an extremely important role to maximize the duration of the battery. Drones roots are back to WorldWar I when many armies tried to develop automatic unmanned planes.