Temperature extremes reduce every vehicle’s battery performance, but study finds all models aren’t equal — and Geotab’s tool invites you to compare

Newly published research from Geotab provides valuable insights on how the range of various electric vehicle models are affected by changes in outdoor temperature.

The findings are based on data gathered from 4,200 fully electric vehicles tracked over 5.2 million trips. It demonstrates what many EV drivers already know: despite the ratings advertised by automakers, EV ranges fluctuate dramatically as thermometers rise and fall.

Cold and heat hurt range

The key insight provided is that across the board, most EVs respond to temperature changes in the same manner, with both colder and hotter days reducing the distance a car is capable of traveling without a charge.

It’s not news that EV ranges suffer in colder weather; Geotab attributes at least some of that impact to the battery power drain required to keep a vehicle cabin warm in cold temperatures. According to the research report published on the company’s blog, “To what degree does temperature impact EV range?” the average EV was capable of using about 54 per cent of its rated range at -15°C.

What fewer people may realize is that the rate of performance decline in the heat is slightly greater.

The “vehicle trip efficiency sweet-spot” was found to be 21.5°C (70°F), at which point many vehicles operated more efficiently than their rated range. The average EV had a range 15 per cent higher than it was rated for, and the top 10 per cent of performers had a range 50 per cent higher than rated.

Unsurprisingly, according to Geotab, 20°-22°C is the temperature humans tend to be most comfortable at, and as such are less likely to use up battery power on air conditioning or heat. Batteries themselves also operate more efficiently at moderate temperatures; if energy is not being used to cool or heat battery packs, more is available to keep the car moving.

The data also indicate that the average EV achieves at least 100 per cent of its rated range anytime the temperature is between 10°C and just above 30°C.

Some ranges sturdier than others

Alongside its findings, Geotab has published an interactive tool which demonstrates how the ranges of individual electric vehicles operate in different temperatures. After selecting a vehicle model, year, and battery size, users can measure how each of the EVs tracked perform in certain temperatures.

As the tool demonstrates, despite a consistent temperature arc, the level of range loss varies fairly widely. The top 10 per cent performing vehicles maintained 32 per cent more range than average, and twice as much as those in the worst 10 per cent.

Note: this post has been updated to correct an earlier error we reported on the range improvement at the “sweet-spot” operating temperature