Autoweek (and other car news outlets) summarize some independent testing: https://autoweek.com/article/green-cars/how-much-does-cold-weather-cut-electric-vehicle-range-quite-bit-aaa-study-finds [autoweek.com]
AAA partnered with the Automotive Club of Southern California’s Automotive Research Center for its tests, which allowed it to run drive-simulating dynamometer tests in 20-, 75- and 95-degree Fahrenheit temperatures in a controlled laboratory setting. This is way more scientific than anything we’d be able to achieve toodling around in an EV in Detroit the next time a polar vortex hits.
A handful of key points pulled from the report:
- The increased use of HVAC systems in extreme temperatures has a bigger impact on EV range than decreases in battery pack efficiency caused by the temperatures themselves.
- Moreover, while both extremely hot and extremely cold temperatures affect range, you’ll incur a significantly larger penalty when heating up a cabin than you will cooling one down. Compare that 41 percent decrease at 20 F to a mere 17 percent decrease at 95 F.
- The BMW i3s saw the biggest reductions in range in both hot and cold conditions, losing 50 and 21 percent of range in cold and hot conditions, respectively.
- The Nissan Leaf was the most versatile, losing 31 and 11 percent of range in cold and hot conditions, respectively.
The other test cars, Tesla S, eGolf and Chevy Bolt fell between these extremes. The article includes a link (pdf) to the original report with many more details. Worth reading if you live outside southern CA and are considering an electric car.
This AC is considering an electric car, and I'm fortunate enough to have am attached garage to keep it warm-ish, probably above freezing, even if the outside temp gets down to 0F (-18C) which is a typical low for my location. That means that any trip will start with a cool (not cold) battery & cabin...but after parking outdoors at my destination(s), I'll have a reduced range for the trip home.