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Winter Climates and the Model S

Has the Model S (which I am very interested in) been tested in colder northern climates? What is the effect on battery life/endurance in sub zero temperatures? Winnipeg has a temperature range from the high 30's (Celsius) in the summer to -40's in the winter. I noticed some posts regarding -20, but it did not say celsius or fahrenheit. In addition, in colder climates, would the battery pack require a "battery blanket"? Lastly, I am wondering that if I was to purchase this car, would I be able to drive it all year or have to park it in a heated garage for 3-4 months? I thank you for your time and await your response.

Can Eng

There are also other parts of the car which cause problems.
The door handles of Model S are coming out automatically when you press on it or come in the near of the car with the key. But when this is frozen or full of ice I'm not sure if you can even enter the car.
Also the trunk is opening electric. So when there is heavy snow on the back of the bar I hope the electronic engine for opening the trunk will not be destroyed.
But I think hope all this things are tested by Tesla.. ;-)
I live in Austria and I have similar problems with "normal" cars and door handles.. :-/

That -20 is celcius. For Roadster there is a advice not to leave your car outside unplugged over -20 celcius cold. -40 C is a lot more

For those that has not experienced that -20C is a temperature that you can go outside for several minutes without something like gloves and you wont get frost bites with winter shoes as long as you keep moving but in -40C you will get frost bites almost immediately to any exposed low circulation area (feet, hands) especially if it is associated with a wind, and those shiny indoor walkers are definitely not enough. You can actually feel how air that you breathe tries to freeze moisture in your lungs.

Ice in -40C is also very hard. Not that slushy snowy stuff you get near 0C temperatures. If you have ice buildup in for example door caskets it is nearly impossible to open that door without ripping those caskets to pieces, so worry about door handles is a real one.

The trunk on the Model S appears to be more of a hatchback style as opposed to a conventional trunk.

My last two Lexus (400h & 450h) both had electric tailgates.

Although I generally would clear the snow off of the rear window of the vehicle prior to opening the hatch, the electric motors in the Lexus were always up to the job. I'm sure Tesla will take this into consideration.

Thank you to all that replied. I would imagine that the pop out door handles could be a problem, especially during/after a slushy snow storm. Typically, I carry a small canister of "Lock De-icer" around in the winter to unfreeze the car locks if they get stuck.

As for the trunk, it would not be a problem as long as you could access the interior. Most people in winter climates who care for their vehicles tend to brush the snow off before driving away.

My real concern is whether the car will be/could be equipped with an auxillary battery blanket that could be plugged in similar to a traditional block heater. Or is it by plugging in the car to charge that you are creating enough battery heat to keep the system warm?

Lastly, I would also imagine that as a luxury car, it would be equipped with all the necessary climate controls for a winter environment.

Thank you and I await your responses.

Can Eng

I could imagine that interior of the car could be warmed up when plugged in. I don't know if that would be enough to get rid of a snow blanket or iced door handles??

Car has internal battery AC. It will keep the battery warm as long as you keep it plugged in (and even if not, as long as battery has charge left).

Problem is prolonged periods in very cold without chance to plug it in. I think Li-ion batteries might get damaged. Not all though, so it is question of what chemistry Tesla batteries is using. Maybe also what liquid they are using for AC, maybe that freezes over over -20C cold, and that is the reason they say that it should not be left without plugging in -20C and not the actual battery.

There is some contradictory information about Li-ion batteries in the net. Some say "do not freeze", some say that it wont hurt it much if at all as long as it is only half-way charged and you warm it up before using or charging. I too would like to hear what really can happen if you leave it out in over -20C temperature without plugging in.

Lithium reacts very strongly with water (lithium is alkali metal) so lithium-ion batteries do not contain water. Freezing that is not an issue here.

I think Tesla is using different battery chemistry for 300mile version and I just found out about Boston Power Swing batteries:

http://www.boston-power.com/sites/default/files/documents/BPOW0008%20Swi...

(From Autobloggreen about Saab 9-3 ePower, and then some surfing).

That one says its operating range is between -40°C-+70°C. Plenty for me. It also has quite good volumetric energy density of 420Wh/L which means that Model S roughly 90kWh 300mile battery would be about size of 214L using those. 214L is about 10cm * 150cm * 150cm. Should fit nicely into bottom of the Model S.

I'm curious what battery type Model S will use for 300mile version. Clearly it is possible to get that easily fit into car, but that operating temperature is what interests me.

While the batteries getting too cold is a concern, it's a minor one. The major one is the cooling system around the batteries that's nestled inside the battery pack. If the coolant that circulates inside there freezes, then the battery won't able to regulate it's temperature anymore, and THAT is damaging to the batteries.

um...how bad will range degrade when its -30, you have the heater on full blast and the headlights on? I mean come on, simple thermodynamics 101...you would have a surface area of at least 1.5M squared and a rate of heat loss through the glass and metal that would be dissipating quite a bit of heat so the heater would have to pump out a significant number of BTU's to keep the car warm inside for the passenger...I am thinking you will consume at least 1500-2000 watts at full tilt. That's a LOT of energy. its the equivalent of 2HP-2.5HP. Its also a lot of amps! Lets say the pack is a 60 volt pack...its probably higher than that but just for arguments sake. 1500 watts/60 volts= 25 amps! again at 120 volts would be 1500 watts/120 volts=12.5 amps! that's a huge amount of current just to stay warm! You are not going to get 300 miles range with that going on!

Speed, outside temperature, driving style all going to affect your range, pretty much a given whether an ICE, Hybrid or BEV.

You are not going to use that 2000W all of time. Initial heating the cabine maybe, but after that it drops quite fast. What affects range in winter time is increased rolling resistance from stubbed tires and snow. Heater is not going to affect that much. In fact cold weather means that there is not going any power to cool down battery pack and that actually saves some energy. Headlight effect on range is minuscule. Tiny. Less than tiny.

From what I've read, with either the A/C or the heater on full bore for 8 hours, you'd loose about 10 miles of range. Trust me, it's a pittance.

So the heater wont use so much electric that a diesel heater will be installed after the car is imported to Norway?

Not a chance.

Timo;

-40°C is pretty rough, but -40x°F is just as bad!

Heh. ;)

I've experienced -65°F, and -35°F with a moderate breeze was much worse.

-65°F is evil. I agree that with wind even -20°C is a lot worse than a -40°C calm weather. Can't say if it is worse than -54°C though. You need to have quite a wind to make it worse than that. You might have different standards for "moderate breeze" than I have.

Let's wait and see how the prototypes do in the freezing cells. Anything under 0°C is cold for me, but I assume Tesla engineers will come up with a car suitable for 99% of this earth's weather.

From Tesla - but by email, I trust they will not mind if I share this:

..."Again, it is hard to give you exact examples about the Model S since it is two years away, but I can let you know how the Roadster is performing in the cold. We actually just sold our first car 200 km north of the Arctic circle in Norway! The salt on the roads has not been an issue, as the Model S is made out of aluminum (the Roadster frame also is aluminum, though the body is carbon fiber). Neither of these materials rusts and are very resistant to corrosion. A heated garage is not necessary, as the battery on the car is kept warm when it is plugged in (which most customers do anyway every night). The door handles on the car are electric (as opposed to mechanical), so freezing has not been a problem on them. We do offer snow tires sets and our traction control system is incredibly advanced and helps the car perform well in adverse conditions."

hmm they dont use salt that high up north, as the temperature has to be close to 0°C to work

That's only at winter. In spring and in autumn there are temperatures close to 0°C. At summer it is way above melting point, so no need to use salt then either.

Oh, they have started using salt on the roads up north in norway also. It doesnt change from above freezing to -20C in a day.;-)

I live in Alta, 69degrees north and they do salt the roads regulary when weather permits.

http://cache.gawkerassets.com/assets/images/4/2010/11/500x_cartz.jpg

Above link is battery life vs. temperature - and why Tesla has invested in better cooling technology than Nissan. My question would be, in colder climates, would one not expect to see longer battery life? Instead of 7-10 years in California, extrapolate from the chart linked above (cooling system notwithstanding - an extra battery load btw) - could we see an extra 4-7 years of battery life?

@Ad van der Meer: Don't forget occupants contribute to internal temperature gains. Just sitting there one body produces about 100W just sitting there. Add 3 more occupants and your car is heated! Condensate is usally more of a problem up here, defogging a car before getting going... it would be great if Tesla built-in an electric resistance heater that only came on when the car was plugged in - akin to block heaters in a way. It would be great to have the car start a de-icing and defogging routine at 7am, just in time to have a nicely warmed, thawed and condensate free interior before getting on the road. Adding a removable dessicant filter might help reduce 'relatively' moist cabin air - something you just don't need in an ICE car as the cabin becomes the defacto heat dump and you just blast the interior until the temp is high enough the RH is not an issue. If the car was designed to lose less heat than an ICE car (ie. filling out body components with flame-retardant PU foam) it would both increase body stiffness and reduce cooling and heating system loads. But I am just thinking out loud here...

Andyro,

Filling out the body panels with foam would also contribute to a quieter interior due to the sound absorption of the foam. In addition, I would also like to see a small resistance heater for the interior of the cabin to keep the car warm when plugged in.

@ Timo:

i saw the link: http://www.boston-power.com/sites/default/files/documents/BPOW0008%20Swi...

that cell is 90 grams, as far as i know for 300 miles version they are using 8000 cells means 90 garms x 8000 cells = 720 Kg on top of that around 150 Kg of casing and cooling system means around 900 Kg.

How is that possible that a car company comes up with 1 ton of battery pack ?

Moreover boston power on cell is 4.4 Ah x 3.7 Volt = 16.28 watt-hr !

8000 cells x 16.28 watt-hr = 130.240 KWh battery pack !!!!!!!!!!!
as far as i know they are using 85 Kwh battery pack for 300 miles.

Old news. This is what we know about the model S battery.

http://www.teslamotorsclub.com/showthread.php/4588-Tesla-Model-S-The-Bat...

It certainly does not weigh a ton.

HA.....!!!!!!

thanks qwk for that update

Thanks Andyro for the info. In the message from Tesla, they mention: "A heated garage is not necessary, as the battery on the car is kept warm when it is plugged in (which most customers do anyway every night)".

Sure, I understand this. If the car is plugged in, there is no problem.

But what if it's not plugged in and stays outside of a garage overnight -or- it's parked for 12 hours during daytime, unplugged in an office parking lot and the temperature in both scenarios is cold (-20 or -30 Celcius)?

Will the onboard battery heating system be able to maintain the battery temperature to an acceptable level solely using the power of the batteries themselves?

Yes, with one caveat. If the battery is near empty, then heating it can drain it to empty and after that pack freezes. I don't know the temperature limits of the Roadster batteries, but I think -20 is not enough to actually damage them, they just practically shut down at that cold. -30 might be too cold. Both cases battery liquid cooling system might freeze too, and if that happens then there is quite certain damage somewhere.

AFAIK battery heating doesn't require much power, you probably can leave it outside for a week unplugged if it is full.


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