Retaining 90% range at -40°C sounds like a game changer, almost too good to be true. I'm definitely going to need to see some third-party real-world range tests to validate those claims before getting too excited.
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.
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/...
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.
Those two things very different.
That's not exponential because the speed (v) is not in the exponent. In fact, it's quadratic.
Corollaries: The power required to push the car at speed v will be proportional to Fv ~ v^3. The gas spent over time t ~ energy spent ~ power time ~ v^3 * time.
But TBF same factors affect ICE cars
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.
>your values may actually be correct
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
As long as you have a heat pump harvesting the waste heat to keep the battery up to temp.
But might be significant on short drives, 10kW for the first 3 km is massive.
AFAIK most EVs already use heat pumps today, so the future happens whenever sodium batteries become mainstream.
Nope, the Mach E and Lightning both have a heat pump (well, just the Mach E now, I suppose, since the Lightning is out of production).
Obviously Tesla and the like are more luxury cars but if EV is to become mainstream they need to compete with ICE Kia's and Volkswagen.
Interestingly, the Hyundai Inster (20k EUR) and Renault 5 (25k EUR) both have heat pumps as standard equipment.
But if they add buttons back as planned, I might be willing to try a new id.4 in 5-10 years.
https://electrek.co/2026/02/05/first-sodium-ion-battery-ev-d...
https://www.energy.gov/energysaver/fuel-economy-cold-weather
At -40F (-40C), it's generally good practice to just stay inside and not drive at all...
Is that actually true once the engine has reached operating temperature?
> Fuel economy tests show that, in city driving, a conventional gasoline car's gas mileage is roughly 15% lower at 20°F than it would be at 77°F. It can drop as much as 24% for short (3- to 4-mile) trips.
1) winter blend fuels have less energy per volume, that doesn't make your engine any less efficient by energy but it does by volume of gas
2) lots of temporary cold effects: fuel vaporization, thick lubricants, etc. these things become less of a problem as the engine warms up but some energy is still lost on long drives
3) air resistance: all aerodynamic forces are linearly proportional with air density. At a constant pressure there's about a 15% difference in air density between the hottest and coldest places you can drive (and thus 15% less drag on a hot summer day than a cold winter day). aerodynamic forces are proportional to the square of your velocity and they become the largest resistive force around 50mph -- so at highway speeds you're losing efficiency because you have to push more air out of the way
4) energy used to maintain temperature: this is hard to calculate but some engine power is lost because the energy is used heating up the engine block and lost to the environment
5) the Thermodynamics 101 engine efficiency goes UP with increased temperature, but it's got a lot of real world effects to compete with, no spherical cows and all
Not sure the engine ever reached "operating temperature" on that drive.
I had a car that developed a stuck-open thermostat and did the cardboard trick to get by until I could replace the faulty part.
It has an 18.8 gallon fuel capacity (https://www.volvocars.com/lb/support/car/xc60/article/dfc6f0...)
That’s a max range of 470 miles. You would need much greater fuel efficiency above 34 mpg to get to 650 miles on an 18.8 gallon tank.
Also you are quoting a value for the B5, which is not what I have, mine is a T8(and before you ask - no, I didn't have any opportunity to charge it anywhere on the way).
The point you are DESPERATELY trying to miss is you can easily "recharge", a "dead" ICE at home too
Eh? All I can see is you DESPERATELY trying to push the narrative that it’s common for people have barrels of fuel at home which is a pretty weird thing to try and prove since everyone reading this will know it’s not true.
'22 Ford Escape hybrid
The remaining miles thing shows less than that on a full tank, but I've been pretty consistently getting upper-600s between fill-ups.
I suppose it would probably be less if I went on the interstate more.
Assuming a 1000km range is a very strange thing to do, as it's a fringe feature that almost no one needs or wants! Recall that "almost no one" means that there's still some, an existence of a handful of people on HN is quite consistent with "almost none."
Which I would expect to typically find something that's, um, fairly typical on characteristics I wasn't selecting on.
Since the Lithium battery prices dropped, there are many Sodium battery companies simply abandoning the research or shuttering. Not a good sign when smart people jump ship.
The Na cells also have lower energy-density, and currently fewer viable charge cycles. One can still buy evaluation samples, but it takes time to figure out if the technology will make economic sense.
Best regards =3
There could be other reasons. Maybe they just cannot compete with CATL.
we can always afford to wait and see.
Have a great day =3