Over the past five years, FleetCarma has been logging conventional vehicles in fleets to determine suitability for EV replacement. It also created an EV monitoring solution since existing telematics systems were unable to read and log the new EV signals.
The result is a large database of real-world EV performance, and from time to time the company analyses the dataset to look for interesting trends. One recent report by CEO Matt Stevens, published in latest issue of Charged, plotted the range of energy consumption for different BEV models across real world operating temperatures.
A quick glance and the chart revealed that the shape of the Model S curve is notably different than the others. “Unlike all of the other plug-ins, which show a continuous rise in energy consumption as soon as the temperature drops below standard thermostat settings, the Model S shows a much flatter curve until 25° F (-4° C). This correlated to significantly lower auxiliary loads for the Model S in these temperature ranges as compared to other BEVs,” wrote Stevens. “Unless Tesla owners tend to wear significantly warmer coats, this seemed odd.”
So, the company dug a little deeper into the data between trips and uncovered a notable difference between the Tesla and other plug-ins.
“Nearly all of the plug-ins that are logged in the FleetCarma system wake up between trips and perform some battery management in cold weather, whereas Model S wake-ups are more frequent, last longer and draw more energy,” explained Stevens.
“At 25° F, one Model S would wake up at six-hour intervals, performing maintenance operations for just over two hours, drawing 400-500 Wh in energy. The result is a more conditioned battery. While the wake-up procedure is common, the increased usage of this process in the Model S shifts more energy consumption from during the trip to between trips.”
Top Image by Robert Nordqvist © (used with permission)