Electric propulsion be it on or off the ground have high standards in order to compete with the internal combustion engine. Requirements peak in off-ground applications due to the extreme danger of fire/malfunction in these situations, the increased load requirements for human transport, and the need to reduce weight and volume for aerodynamic considerations, as with UAVs. The internal combustion engine performs well in each requirement for both on-and off-ground applications, proving a strong competitor to the electric powertrain. Potential cost-savings and vertical takeoff/landing are appealing characteristics of battery-powered flight . Two-wheel electric vehicles (i.e. electric scooters/bikes) also present an opportunity for batteries .