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Battery Temperature limits

Battery Temperature limits

Now that John & Jill are the very first to complete All-Supercharger-Cross-Country Trip from the East Coast to the West Coast,

May be we should challenge them the same but this time from LAX, CA to Anchorage, AK :)

That's almost 3,500 miles going north and through our neighbor Canada.

However, there is a lingering question that can Tesla battery run or be plugged in with ambient temperature below -22F for more than 24 hours as there's a limitation in the Owner's Manual, page 83?

"Temperature limits

Do not expose Model S to ambient temperatures above 140F (60C) or below -22F (-30C) for more than 24 hours at a time."

Logically, if it is plugged in or driving, the HVAC system would automatically optimize the battery temperature.

Any brave souls who can give us a dry run here :)

logicalthinker | January 27, 2014

I would have thought some owners above the arctic circle in Norway would have had to deal with this already.

I guess they are garaging their cars.

-22F is absurdly cold. Then again, didn't John and Jill experience this temp on their cross country trip? It could be a real issue for northern owners.

If I travel up north, I will take an extension cord, rope/straps and a electric blanket, and throw it under my Tesla and snug it up under the battery. It takes only a few cents to run an electric blanket all night and would physically ensure the battery stayed warm. Of course I'd also plug the car in.

logicalthinker | January 27, 2014

My Tesla. Ahh. Sounds so nice. Just hasn't happened yet. :) <3

NKYTA | January 27, 2014

@logical, why bother with the e-blanket if you can just plug the car into a socket and let your MS handle the battery itself?

A real issue in northern climes is having a diesel with a block heater, and having that fail!

logicalthinker | January 27, 2014

Well because basically the way I'm reading that warranty above is that it says do not expose your car to temps below -22F for >24hr, regardless of whether or not you have it plugged in.

logicalthinker | January 27, 2014

Clarification: read the warranty. It does NOT say "... unless you have the car plugged in during this time."

No. Rather, it flat out prohibits exposure to ambient temps below -22F for >24hr.

NKYTA | January 27, 2014

@logical, fair enough, but if you only had one extension cord, I'd opt to charge the car.

Now you've got me wondering if I need to carry two when I go to Alaska. ;-)
;-P

logicalthinker | January 27, 2014

In other words, the implication is whatever battery heating system the car may have cannot adequately warm the battery for >24 hr below -22F.

I suspect the lower ends of the vertically aligned cells, closest to the frigid outdoor air (just beyond the aluminum shell) drop below a critical temp despite active thermal mgt., at which point the battery may begin to deteriorate physically or chemically. I totally am guessing but it makes physical sense.

logicalthinker | January 27, 2014

I'd always plan ahead and have a 240V plug available for the car, and then use a regular wall outlet for any extra power like a security blanket. ;)

Nobody up there could make fun of you, because they all are plugging in their stupid gas cars overnight.

logicalthinker | January 27, 2014

Similar thread:
http://www.teslamotors.com/forum/forums/one-more-trytesla-and-cold-weate...

Sounds like they are unaware of the owner manual warning, or at least it wasn't being discussed.

Tâm | January 28, 2014

At least we don't have this kind of broken off car handle problem at -24F:

crazybrit | January 28, 2014

While the temp may dip below -24F, it never stays that cold for >24hrs in Minnesota. Before I bought the car, I went back through historical temperature records to check, because that was a concern for me.

jkn | January 29, 2014

This 24 h limit is a very serious problem, if exceeding it damages battery. We don't often have long periods below -30 C here, but a few 100 km north it happens almost every winter. Even here we had couple weeks at -40, but it was almost 30 years ago.

If a block heater in a diesel fails, engine is not damaged. Starting it might be impossible until warm weather.

I have an old car with plastic door handle. I have broken it twice already because of cold and ice.

Tâm | January 29, 2014

Why worry?

Look:

Every single state of the 50 states, including Alaska, has now owned a Model S.

If they can do it in Alaska, then our LAX-AK team should be able to do it too :)

http://www.siliconbeat.com/2014/01/29/with-a-registration-in-jackson-mis...

Doug H | January 29, 2014

When traveling through Indian during the polar vortex, I experienced -21 while at a Supercharger at night. But that was as low as it got during the trip. I didn't know I was in danger of ruining the battery.

Brian H | January 29, 2014

Surprised plugging in doesn't make a difference. (?) Does 120V vs 240V matter?

Tâm | January 30, 2014

@Doug:

The condition must exist continuously for over 24 hours. If there's a break in between, then the clock is restarted again.

1) In most situations, US weather never dips below -22F CONTINUOUSLY for over 24 hours.

2) Even if it dips below -22F continuously for over 24 hours, most people would bring it into a garage for refuge during that temporary condition.

@Brian

I assume the battery pack heater can only heat so much and it is not designed to be overworked continuously more than 24 hours.

hamer | January 30, 2014

This is like diabetes. If your serum glucose level is 99 mg/dL, you don't have diabetes. If it is 101, you do. That's absurd. There is not a clock in your battery counting the number of hours at which you're below -22F, and your car is magically undamaged if you're below for 23:59 hours:minutes, and damaged if you're below for 24:01. Or for that matter if the temperature is -21, you're just great, and if it's -22, you're screwed.

Tesla gave us a warning, but I would not be too happy to be pushing close to the limits, nor would I assume I was screwed if I went slightly past the limits.

Definition of what battery damage they are discussing and an ROC curve would be nice.