The Truth About Commercial Battery-Electric Vehicle Range and Efficiency

E = mv². That’s the equation for the energy required to move a vehicle. This energy equals the mass of the vehicle times the velocity squared. Yes, other variables matter, such as coefficient of drag and powertrain efficiency, and the energy draw of accessories such as air conditioning, heating and lifts, but all of those are small contributors relative to mass and speed. In other words, the range of a commercial electric vehicle depends primarily on the vehicle’s weight, its drive cycle, and its battery capacity. That’s down to physics; and one would expect similar vehicles to have similar ranges.

However, the ranges claimed by some of the vendors in the industry make one wonder if they’re somehow in a parallel universe where physics is different!

Since commercial vehicles are categorized based on gross vehicle weight, the playing field is level there.  The drive cycle is generally independent of the vehicle, thus the playing field is level there too. The benefits of a “ground-up” or purpose-built vehicle design (as opposed to converting existing vehicle platforms to electric – read more) in fact have very little impact given that the mass and drive cycle are the same.  Certainly a BEV-designed vehicle may achieve higher payloads due to having a lower base vehicle mass; but again, this will have less than a 5% impact.

So the bottom line is, if you see a commercial electric vehicle manufacturer or sales person advertising a range or efficiency more than +/- 10% different than the industry fit-line in the chart below, you should immediately ask for their dyno and track results and their test criteria.

In one recent case, we saw a competitor advertise 50% higher range/efficiency than the industry average, but after some searching we discovered that they had run the test at zero payload and a steady 28 mph. Clearly no customer will see those results in real-world driving, so this kind of manipulation is not helpful to anyone.

Lightning eMotors has CARB-certified dyno range and efficiency test results for all of our Class 3 (Ford Transit) vehicles. Our results are industry-leading because our control algorithms for regenerative braking are the best in the business, and we use the very best battery, motor, and EV accessory technologies. These advantages put us a little to the right of the fit-line in the chart; but not by an amount that places us in Physics La-La-Land.

Lightning’s Class 3 results are the only data points on the chart based on certified EPA City/Hwy dynamometer testing.  All other data points are based on each OEM’s self-reported modeling, or on-road testing using whatever algorithm they chose.

We are now working to test all of our other platforms on dynamometers (a more difficult task because there are very few certified heavy-duty dynamometers). In the meantime, we will use standard road testing that is representative of customer’s real drive cycles to provide range and efficiency data. We believe every EV manufacturer should be forced to the same standard — and if the certifying agencies do not force it, we believe that customers should and will.

 

Sponsored by

by Tim Reeser, Lightning eMotors CEO

Source: https://www.fleetforward.com

CUT COTS OF THE FLEET WITH OUR AUDIT PROGRAM

The audit is a key tool to know the overall status and provide the analysis, the assessment, the advice, the suggestions and the actions to take in order to cut costs and increase the efficiency and efficacy of the fleet. We propose the following fleet management audit.

FLEET MANAGEMENT AUDIT