The range of electric vehicles varies depending on the application and nature of use – for example, the amount of installed energy on the vehicle, and the environmental conditions in which the vehicle will operate. For instance, a terminal tractor's operation range might vary from 4 hours to 10 hours depending on the energy on board, carried loads, climbed ramps, drivetrain efficiency, and other factors such as operating temperatures, climate pre-conditioning of the vehicle before work starts, and auxiliary usage.