Real-world impact of speed and temperature on EV range
Data from 3 million journeys reveals how cold conditions and fast speeds reduce battery range.
Fleet decision makers can analyse the impact of both speed and temperature on the range of electric vehicles, thanks to insights from aggregated data covering 3 million EV journeys and 550,000 hours of battery-powered driving.
As a rule of thumb, the faster an EV is driven and the colder the temperature, the shorter the distance it can travel.
For fleet operators, however, a far more accurate appraisal of the impact of speed and temperature provides valuable information when planning routes for EVs and identifying new EVs capable of fulfilling operational requirements on a single daily charge.
EV Range Analysis
The tool compares the range of both an electric car and an electric light commercial vehicle, equipped with a typical 65kWh battery.
The results show that temperature has a much greater impact at low (urban) rather than high (motorway) speeds. They also reveal that LCVs lose range much more quickly than cars at faster speeds.
Charlotte Argue, Senior Manager of Fleet Electrification at Geotab, said: “Understanding what causes range loss can increase confidence for EV drivers and fleet managers. It provides guidance on selecting the right vehicle for the job and conditions at hand.”
Geotab has shown that EVs can exceed their official range by 15%, but that range can fall by as much as 50% on extremely cold days, due to the energy required to keep both the driver and the batteries at a comfortable temperature.
“At low speeds, a 10 degree change in temperature will have a much larger impact on range than any change in temperature at high speeds,” said Argue.
Optimum speed changes with temperature
The optimal temperature to maximise range is 20 degrees Celcius (68F), but the ideal speed changes depending on temperature.
For a car, Geotab found that its range is highest at 30.5kmh (19mph) at 20°C, but if the temperature drops to 0°C the optimal speed doubles to 60kph (37mph). Faster speeds get drivers to their destinations more quickly, which means less energy is used for heating or air conditioning, but use more power to overcome drag.
For a van, however, drag is much higher, which means that at 20°C the most efficient speed is just 26kph (16mph), and this only rises to 40kph (25mph) at 0°C.
This matters for a fleet operator planning routes.
“Imagine it’s a mild day, about 21°C (70F), and you have two options: take the highway and drive 113kph (70mph) or take city roads and drive 48kph (30mph). If maximising range is your number one priority, then regardless if you’re driving a car or a van, you’re best to take the slower route,” said Argue.
But when the temperature drops to freezing, the car uses only 13% more energy on the motorway and the driver will reach the destination twice as fast.
“However, in the light cargo van, your loss is 26% in range by choosing the highway route versus the city street. When it comes to the light cargo van, speed still plays a significant role,” said Argue.
“The reality is for most fleet applications, today’s EVs can complete their trips on a single charge regardless of speed or temperature. For the longer routes, having an understanding of seasonal temperatures and road speeds can provide guidance on trip planning, and whether a charging stop should be part of the itinerary.”
New telematics tools
Geotab’s EV Range Analysis was one of three tools that it unveiled today, alongside Data Connector, which curates specific fleet data sets and makes the data available via a ‘no code’ integration with the fleet’s business intelligence tool, such as PowerBI, Tableau or Excel. This overcomes data silos, integrating data from different sources, such as vehicle maintenance or finance, with fleet data.
The telematics specialist also announced that engine manufacturer Cummins will provide its customers with over-the-air updates to engine control units via Geotab’s GO9 device.
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Images: Shutterstock and Geotab