[SKolja]

The worst range I had on GoM was 170km when temperatures dropped to -10 degrees Celsius. But I drive 99% in city where is hardly any snow. If I know that it is going to be freezing overnight, I keep the car always on cable and setup the pre-heating. This is helping the battery to stay in reasonably good thermal conditions (above 5C). Car is always park outside.
To me, one of the factors you should investigate is temperature and voltage of battery pack/cells. It can well be, that one(or more) of the battery cell performs badly in cold temperatures and BMS is compensating for that (it is trying to protect cells to fall bellow certain voltage) by reducing available range.

 

[HandyAndy]

I've seen a paper where dropping the temp of Li-ion cells from 20C to 0C reduced the capacity by 5%.

 

[vanctour]

I've seen a paper where dropping the temp of Li-ion cells from 20C to 0C reduced the capacity by 5%.

I wonder if there was any mention of whether that battery capacity will restore itself when the weather gets warmer, or if it leaves permanent damage. If it is a seasonal capacity reduction, then I can live with that. But if the battery permanently loses 5% each winter, then I'm not pleased at all.

 

[HandyAndy]

No, it's not a permanent thing. Just the chemistry isn't so keen to operate at low temperatures. Maybe there's more internal resistance so wasting a larger %age of the power when you draw it off. Purely a seasonal effect. Summer sees you back to normal!

 

[jneron]

To me, one of the factors you should investigate is temperature and voltage of battery pack/cells. It can well be, that one(or more) of the battery cell performs badly in cold temperatures and BMS is compensating for that (it is trying to protect cells to fall bellow certain voltage) by reducing available range.

That's a good point, any idea how I can do that?

 

[jneron]

I've seen a paper where dropping the temp of Li-ion cells from 20C to 0C reduced the capacity by 5%.

I wish it was only 5%!...

 

[Bosson]

EV Range vs. Temperature Range Comparison Tool | Geotab

 

[HandyAndy]

Nice tool, but badly needs updating with newer cars!

 

[alsiik]

My yesterday's experience, pushing the limits of the poor car a bit

Was performing till 2AM and then had to drive back home 160 kms of which exactly 100 was a highway drive (flat, no steep climbs), 30 was a outer city drive (80-100 km/h), 30 was countryside driving (90 km/h limit, myself adding +10 to that).

Less than ideal conditions, -4 degrees Celsius, a bit windy (head wind)

Charger was next to the venue so I could prepare - pre-heated cabin and charged to 100% SoC. When started, car showed 242 estimated range without heating. Auto setting with 20 degrees inside.

For the whole 100km highway drive, Cruise control was set at 125 km/h. Zero traffic, didn't have to slow / speed up once.

Managed to get home without charging at 3.50 AM, overal consumption was 18.9 kWh/100km, arrived with 6% SoC.

 

[jneron]

So the range showed 242km, but you only got 160? That doesn't sound ideal.

I'm continuing to monitor mine. We had a cold spell for the last 10 days or so (-25C daytime high), so I thought this would be a good opportunity to measure distance with relatively constant (although cold) temperatures. This time, the actual range was within 10% or less of the predicted. Maybe it's just variations in temperatures that throw off the GOM? I'm starting to think there's nothing really wrong, it's just "the way it is".

 

[HandyAndy]

...For the whole 100km highway drive, Cruise control was set at 125 km/h. Zero traffic, didn't have to slow / speed up once.

This is quick travelling in any weather for a BEV! Translates to 77 mph, speedo probably a bit optimistic so a real 72 mph I'd say.
Aero losses go up wih the square of your speed (also Rolling resistances go up but only very slightly so ignore those).
Going at genuine 72 versus genuine 60 uses (72*72)/(60*60) = 1.44 so 44% more wind force acting against you!
So 44% more energy used on the trip for the aero losses portion.

I did some calcs a while back, and estimated that at 60 mph the Rollign Resistance is using 75% of the energy, and the windage losses 25%. So I'd expect travelling at 72 versus 60 to use something like 15% more energy, ballpark figure.

 

[alsiik]

So the range showed 242km, but you only got 160? That doesn't sound ideal.

I'm continuing to monitor mine. We had a cold spell for the last 10 days or so (-25C daytime high), so I thought this would be a good opportunity to measure distance with relatively constant (although cold) temperatures. This time, the actual range was within 10% or less of the predicted. Maybe it's just variations in temperatures that throw off the GOM? I'm starting to think there's nothing really wrong, it's just "the way it is".

I'm quite sure that if I had set CC to 100km/h during the highway part, I would have managed to get to that estimated range. The car's electronic surely counts with the outside temperature and battery temperature while calculating the range, but it may also somehow take your average consumption into account. That's 13kWh/100km for last 6000km, now I had 50% higher consumption.

Overall I think you're right, it's not a bug, it's a feature of electric driven powertrain. You know, 5 years ago, when electric cars outbreak was about to start, the last generation of ICE 2.0 TDI VW cars (most common in my country) had a max speed of 220km/h, good acceleration figures and consumption of 6-7 litres/100km, which gives you 1000+km range.
The mindset of these cars drivers is still very strong now, hence the first question is always about the range - and EVs cannot compare to diesel behemoths for sure.
This is slowly changing now, no more solely ICE cars will pass through the newest Euro7 regulations, their electrification makes them more expensive and the traffic is getting slower overall.

 

[alsiik]

This is quick travelling in any weather for a BEV! Translates to 77 mph, speedo probably a bit optimistic so a real 72 mph I'd say.
Aero losses go up wih the square of your speed (also Rolling resistances go up but only very slightly so ignore those).
Going at genuine 72 versus genuine 60 uses (72*72)/(60*60) = 1.44 so 44% more wind force acting against you!
So 44% more energy used on the trip for the aero losses portion.

I did some calcs a while back, and estimated that at 60 mph the Rollign Resistance is using 75% of the energy, and the windage losses 25%. So I'd expect travelling at 72 versus 60 to use something like 15% more energy, ballpark figure.

Thanks for the exhausting maths, it's always very interesting.
I drive quite often to my parents house, which is 120 km from door to door, 85kms is only the highway (climbing some 200metres above sea level overall)
I know that when the battery is fully charged, I can afford setting CC to 130km/h, arriving at the destination with some 8-28% SoC left - depends on the time of the year + weather.
The thing is the highway limit of 130km/h in my country. If you're cruising at 100-110, you're just a tad faster than trucks and that makes the ride dangerous. Mostly because employees with company ICE cars commonly do 135km/h GPS on highway, which translates to some 140-145 on the speedo.