Vehicles employ various power-sources for propulsion. Such power-sources may include an internal combustion engine and/or one or more electric motors or a fuel-cell.
Each of such power-sources typically requires an energy storage device to receive and store an energy charge, and to supply the stored energy in order to sustain operation of that power-source. For example, a fillable tank may be employed for supplying fuel to run the internal combustion engine or the fuel-cell, and a chargeable electrical battery may be employed for supplying current to run an electric motor.
A specific degree of the energy storage device's energy charge generally supplies the vehicle with a finite driving-range. Such a driving-range typically depends on a number of factors which may be related to the vehicle itself, as well as to road and weather conditions. A vehicle operator's driving style may also influence the vehicle's available driving-range on a specific degree of charge.