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teraflop | 21 days ago
This is a big difference because there are all kinds of other factors besides energy capacity that can affect the efficiency of the whole system, and therefore affect range.
Most notably, air is about 28% denser at -40°C than at 25°C, so drag is about 28% higher. So you would expect roughly 28% less range at high speeds even if the battery has no capacity loss whatsoever.
As someone else mentioned, climate control also consumes a lot more power when it has to maintain a larger temperature difference between inside and outside.
gucci-on-fleek|21 days ago
With my gas car, I haven't noticed 30% worse fuel consumption at –30°C compared to +30°C [0]. To be fair, I haven't closely measured the fuel consumption at different temperatures, but I probably would have noticed such a big difference. This is just anecdotal of course, so your values may actually be correct.
[0]: It does occasionally get down to –40°C here, but my car won't usually start then, so I've slightly shifted your temperature range to the values where I've driven most.
rootusrootus|21 days ago
layla5alive|21 days ago
Aspos|21 days ago
schiffern|21 days ago
Note that a 28% increase in drag results in a roughly 22% decrease in range, because 1/1.28 ~= 0.78. Also there are other losses (like rolling friction and constant loads like headlights or cabin heat), so range doesn't scale perfectly with drag. Drag is the main source of loss at highway speed, however
randomname93857|21 days ago
PunchyHamster|21 days ago
But TBF same factors affect ICE cars
jfengel|21 days ago
gpm|21 days ago
I'd add though that rolling resistance tends to be higher, on average, in winter too. When there's often a bit of snow on the roads... Less so on high speed highways admittedly.
[1] https://www.reddit.com/r/askscience/comments/l2cq6b/comment/...
aucisson_masque|21 days ago
Even at 30kmph it's already the majority of the resistance and it scales exponentially with speed so you can imagine how much it matters.
kalenx|21 days ago
baq|21 days ago
Saris|21 days ago