A precision DC energy monitor for electric vehicles

The traditional automotive world uses miles per gallon as a common measurement term that the public and industry can easily understand. The world of electric vehicles (EVs) has needed an equivalent standard for measurement. Something such as miles per kilowatt-hour could be used, but then the low numbers of 3-9 miles per kWhr would make it seem that EVs were much less energy efficient than gasoline vehicles. A better standard would be kilowatt hours, or fractions thereof, per mile-such as watt-hours per mile. To monitor DC energy use in an electric vehicle Brasch Laboratories has developed a precision DC energy monitor. This system was designed to be a low cost precision instrument to quantify energy being extracted from, or returned to, a battery. In vehicle use the continuous digital readout allows for rapid verification of the vehicle's energy use per mile. This instrument was designed to quantify energy use for vehicle comparison, and to be primarily used for vehicle improvement. The rapid feedback of results of changes to the vehicle or driving technique (allowed because energy use can be so easily determined), greatly speeds up the improvement of the vehicle's performance or range.