Driving my Model S in extreme winter conditions

[Johan]

Oyvind,

I think you're right. The battery may be thermally insulated from the base of the "pan", but I think an additional thermal blanket would help to keep the pack warm at speed on the highway when the wind-chill could really affect the temperature of the pack.

I have a feeling someone will develop something that can be bolted onto the bottom of the pan, and as someone mentioned could be swapped on and off with winter tires.

My only concern for this is if it would disturb the aerodynamics underneath the car? From my understanding the fact that the bottom of the car is so flat, without protruding elements like exhaust etc, is an important reason for the car achieving such a low Cd(A)? You're already loosing range in the winter due to many factors such as denser air, more friction on the road, winter tires, increased load on heating - so you don't want to loose even more on aerodynamics of the car's body. Also, if there was an alteration of the air flow it would have the most impact when going fast such as highway speeds, and when you think about it, the one time you need the full range of the car is when you're going long distances which you are usually doing at higher speeds...

 

[pbrulott]

Wonder what the 60kWh or 40 kWh pack behavior will be in the cold? will they be more impacted or less?

 

[Doug_G]

Well, Elon might claim that the battery has good insulation and that power is only consumed initially to heat it, but I just read JakePs post about range in -7C (19F), and he barely got 200 miles out of the pack (182 done, 6 miles left and range charge was not completely finished). And those 200 miles were done by someone trying to achieve good range. He seems to be aware of what needs to be done to keep consumption down, and that tells me that 200 miles in -7 is definitively not a wost case scenario.

In other words, at -7C range seems to drop at least 15-20%. What then at -15 or -20? Is dense air and rolling resistance a huge factor, or could it be that the battery is simply not insulated well enough?

From my experience with both the Roadster and the Model S, there is a large loss of range when you transition from a few degrees above freezing to a few degrees below. Any additional losses at lower temperatures is much smaller.

If the pack is totally cold soaked you will see excess power consumption for the first fifteen minutes or so, while the pack heater is running full blast. After that it settles down for highway driving at about 80% of Rated Range.

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Wonder what the 60kWh or 40 kWh pack behavior will be in the cold? will they be more impacted or less?

I would expect percentage wise it will be the same.

The exception would be pack heating, when starting up from a cold soaked battery. In that situation it would probably be the same amount of energy, which would be a larger percentage of the pack capacity (due to smaller pack).

 

[pbrulott]

Hum, I would think smaller kWh means less cells means less space means less heating required. Overall it would mean the same % loss due to heating than the bigger pack. nothing to back that up though. pure speculation.

 

[William13]

I drove today at -10 to -7 C with a strong cross wind and one hour fifteen minute cold soak while visiting my father in law. We used plenty of interior heat. 170 miles round trip leaving only 16 miles of rated range at the end having started with a warmed up range charge. I drove 30 miles in town and the rest between 55 and 65 mph. Minimal snow, no wet roads.
If it is ever colder or snowing/raining, I will need to carefully watch my consumption to avoid running too low. The projected range and navigation work well for this. The masses will need a slightly better app for this which allows return trips and three points on a trip to be calculated.

 

[JakeP]

+1 on better projection apps, not to mention a projection that considers your navigation route elevations, if you are using Nav. The ability to preheat the cabin and pack using shore power when plugged in will also be extremely helpful.

 

[eledille]

My only concern for this is if it would disturb the aerodynamics underneath the car?

I would be very concerned about corrosion. If road salt gets between the bottom and the blanket and stays there...

 

[anticitizen13.7]

I drove today at -10 to -7 C with a strong cross wind and one hour fifteen minute cold soak while visiting my father in law. We used plenty of interior heat. 170 miles round trip leaving only 16 miles of rated range at the end having started with a warmed up range charge. I drove 30 miles in town and the rest between 55 and 65 mph. Minimal snow, no wet roads.
If it is ever colder or snowing/raining, I will need to carefully watch my consumption to avoid running too low. The projected range and navigation work well for this. The masses will need a slightly better app for this which allows return trips and three points on a trip to be calculated.

186 miles out of an EPA rated 265 miles doesn't sound too good at first glance. That's about 70% of rated range, but even 186 miles is far more than I typically drive each day. Having to drive 70-80 miles in a day is a really bad day for me, and I don't even think that happens once a year.

I guess the absolute worst scenario would add rain or snow, and headwinds instead of crosswinds. I usually just stay home if the weather is bad.

 

[EdA]

Tacking this on instead of starting a new thread:

Today it was under 20F and when I get in the car I like to zoom out on the maps so I can see my whole commute and make the appropriate decisions.
The display seemed to get stuck refreshing and at that point the climate control system went a bit wacky, cycling the heater on and off continuously
and the heated seat controls wouldn't adjust - all while all CPU cycles went to trying to get the map screen to finish drawing...

This happened once before and I rebooted (twice) to get out of that situation...

Anyone else seeing this kind of behavior?

/Ed

 

[Johan]

I would be very concerned about corrosion. If road salt gets between the bottom and the blanket and stays there...

Ok maybe not "only concern" but "main concern" then

Engineering the blanket to fit snugly is a given, since it's insulating properties will depend on that just as much as the aspect you're pointing out. Perhaps with rubber seals or similar.

 

[Johan]

Ok maybe not "only concern" but "main concern" then

Engineering the blanket to fit snugly is a given, since it's insulating properties will depend on that just as much as the aspect you're pointing out. Perhaps with rubber seals or similar.

P.S. Rubber seals:

 

[Mike_Schlechter]

Drove the car when it was super-cold (<10f) last night and this AM, which meant no regen. The car feels really heavy without the engine holding it back, but still handles very well. Also had to deal with cabin warming and black ice. No issues for me (19" wheels).

 

[neroden]

@Doug_G and others with defogging issues in cold northern humid regions:
From Tesla: "We have designed a new vent with much improved defogging flow for very cold regions. It is in testing now and should be available to customers in three to four weeks. It will be retrofitted free upon request."

3-4 weeks! That's brilliant news. We have very high humidity here and I have had fogging / internal frosting problems in every car I drive. And temperatures have been running at 10-20F in the daytime for several weeks.

But if this will be ready in 3-4 weeks, it should be possible to have it retrofitted at the service center before my car *arrives*, and it might even be already-installed. I will have to contact Tesla.

The engineering end of Tesla really takes care of people.

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I had assumed that that there would be adequate pack insulation for cold weather driving as Tesla has said the Model S is designed to operate in Northern climates. Experiences indicate it would operate much more efficiently with better insulation.

I'm not sure there's room under the car.

My house stays toasty with low energy use, but it has *six inches of sprayfoam*, and sprayfoam has nearly the best insulation per inch there is.

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186 miles out of an EPA rated 265 miles doesn't sound too good at first glance. That's about 70% of rated range, but even 186 miles is far more than I typically drive each day.

And more than my worst-case drive, which is a bit under 130 miles.

 

[eledille]

I'm not sure there's room under the car.

My house stays toasty with low energy use, but it has *six inches of sprayfoam*, and sprayfoam has nearly the best insulation per inch there is.

There are actually some new, extremely good insulation materials available. If they are using those already, we're in trouble, if not, they can fix it easily.

Flexible, high-strength polymer aerogels deliver "super-insulation" properties

I also read about a rigid, thin board consisting of aerogel in a vacuum sandwiched between reflective plates. That material is supposed to be even better, but it deteriorates if it's punctured.

 

[pilotSteve]

There are actually some new, extremely good insulation materials available. If they are using those already, we're in trouble, if not, they can fix it easily.

Flexible, high-strength polymer aerogels deliver "super-insulation" properties

I also read about a rigid, thin board consisting of aerogel in a vacuum sandwiched between reflective plates. That material is supposed to be even better, but it deteriorates if it's punctured.

Thanks for that link! I learn so much reading these forums. There are many smart cutting edge Tesla owners and they share great info.

 

[syncdin]

Spray on ceramic insulation may be a great solution: Home Insulation With the Stroke of a Brush -- All About Ceramic Insulation -- Car Ceramic Insulation : Lizardskin

 

[m1ker]

Here are some videos including some sever winter condition ones we made in our Model S.

lightRUNN3R studios
m1kTV playlist
m1ker Tesla videos - YouTube

 

[mnec]

Great Video! Spl liked the Disney trip Video!