Tesla Battery Range in Sub-Zero and Snowy Conditions

Tesla battery range during the winter

Over the month of January I decided to study the impact sub-zero weather conditions had on the battery range of my Tesla Model S and found it to be diminished by roughly 40%. Range will vary depending on one’s driving habits but the effects of winter on a Tesla Model S and its battery range should roughly mirror the data that I was able to collect.

Collecting Battery Range Data

I recorded my Tesla’s rated range at the beginning of the day and once again at the end of the day. I logged the amount of kWhs consumed during my daily journey, the actual miles driven and the average temperature for that day. All of this was plotted into a data grid so that I can analyze the effects winter conditions would have on my battery range. The results were as follows:

Tesla battery range log

Comparing the Tesla Model S rated range display versus the actual rated miles used during winter weather conditions. Results indicate an increase of 21% to as high as a 57% in energy consumption.

 

Results

Plotting the % of rated miles used / miles driven against temperature lets us see the correlation between outside temperature and battery range.

Temp vs Range in Winter

Here you can generally see a trend towards improved efficiency as outside temperature increases. There’s one big outlier which turns out to be a day when the roads were covered in snow and ice. Taking out that data point shows a better correlation between temperature and battery range.

Temperature impact on range

Using a trend line we can see that the outlier at the 57% mark should have been closer to 32% had the roads been more clear. Driving through snow and ice conditions affected the range by an extra 25%.

The data point at the 30% mark during 14 degree is a result of me pre-warming the Model S while it was still plugged in. Warming your car up from shore power prior to taking a trip improves your efficiency.

Summary

Using the data above and a calculated trend line I came up with the table below. This table is showing the actual maximum range I’d expect to get out of a 85kW battery pack which has a rated range of 265 miles:

This analysis is based on data I collected on my car over the course of one month and during a variety of winter conditions. I found it really eye opening to see the rated range of my Model S  go from 265 to a real world average of 143 miles during the winter (90% charge, 40% range degradation). For the 60kW model this would be 112 miles.

Fortunately Tesla appears to be placing Superchargers closer together which will help alleviate any issue with running out of range because of winter weather conditions.

How do you best prepare for winter driving in your Tesla Model S?

  • Expect to use (on average) 40% more power during the winter.
  • Expect to lose about 10 miles of real range for every 10 degree drop.
  • If the roads aren’t dry expect to lose up to 25% more range.
  • Plan your charging and driving accordingly — don’t cut it close.

I hope this information has helped you understand the effects of winter on the Tesla Model S. If you have your own data, observations or questions to share, we’d love to hear them so leave us a note at the bottom of the page.

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Rob M.

Author: Rob M.

Rob's passion is technology and gadgets. An engineer by profession and an executive and founder at several high tech startups Rob has a unique view on technology and some strong opinions. When he's not writing about Tesla, Solar City and related news he's off hacking code, playing video games or hiking the trails of New England with his dog.Rob's Model S details: S85 | Grey / Tan Interior | Obeche Matte Trim | 19" standard | Parking Sensors | Sub-zero | Pano | Premium Lighting | Dual Chargers | VIN: 36801 | Took delivery 4/21/2014.Feel free to follow him on twitter @teslaliving for random thoughts, lots of pictures, news updates etc.

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  • Rick Henderson

    Excellent, thank you. Do you normally preheat the car/battery?

    • Before 6.1 I used to try to warm up for 15-30 minutes before driving. I tried with range mode and without and didnt find significant impact on battery temp. Best effect was to time the charging so that it ended just before I drove but thats tricky and made trickier by a failed UMC.

      With 6.1 it has smart preconditioning that doesnt seem smart so far but I’m trying not to interfere and see if it ever figures out my schedule (I havent so I don’t see how it can).

  • Eli Meyer

    Thank you for taking the time to track and share this data. I have observed a similar reduction in efficiency for my gas burning car. Fortunautrly for you, you have the option of preheating your battery by scheduling your charging to be in-progress when you leave for work in the morning, provided you are on a consistent schedule. I have read that it takes a lot of energy to warm up the battery when it is cold, just like it takes a lot of energy to warm up a gasoline engine to operating tempertures.

    Have you tracked your efficiency through a drive cycle? I suspect a lot of your efficiency loss occurs in the first five miles for warm up.

    • Definitely. Its more pronounced when you have more limited range than ICE cars. The BMW i3 goes from 80 miles of range down to 40. Thats the same 50% but it could make the car a fair weather only car. Fortunately the Model S can handle my 100 miles a day average in the summer and winter without any problems but it was an eye opening study for me.

  • ElectricSteve

    I live in Switzerland (brrr cold now, around 25 F) and when i pre-heat the car in the morning, i lose around 10% range due to the severe cold.
    This is when the roads are free of snow and slush.
    When plowing through snow, the rolling-resistance of the tires increases really dramatically and i lose about 25% on average. I run on 19″ winter-tires. But this happens with ICE cars as well of course.

    • Ive got the 19″ tires too (Nokians). 25F is what i’m calling a warm day. Below 20F is on the colder side.

  • Thanks Bjorn, love your videos

  • mr_charlie

    let me share my experience and let it serve as a warning.
    on a recent road trip up north in very cold weather I suffered severe range loss while parked over night. We arrived at our hotel with 40+ miles of range, the super charger is 15 miles from the hotel so I assumed that I could wait until the morning to charge up and continue the journey. This turned out to be a bad assumption on my part because the car was NOT plugged in and the temperature dipped to 15F, the car lost over 20 miles or range leaving me with 20 miles of range to go 15+ miles to get to the supercharger. since the battery was cold to start my range dipped almost immediately, to the point that the new 6.1 range estimates were telling me that I wasn’t going to make it. fortunately it was around 6 am and the roads were empty so I was able to limit my speeds in order to conserve range. As I got within a mile or so of the SC I was out of range and the message CHARGE NOW came up. fortunately I made it to the SC with no apparent harm to the car, 2014 model S 85. the moral to the story is that you must be aware that the battery will cycle to try to protect itself from frigid temps and there can be a significant loss of range. If I went to the SC before retiring for the evening or if I could have had access to a 220 connection I wouldn’t have wound up in such dire straights.

    • Good advice. I’ve heard of losing 6-7 miles overnight but 40 is big and scary. Thats good to know.

  • Tor

    Nice collection of data. I haven’t had enough kilometers in my Tesla yet to compare to your numbers, but it’s a wet winter here in Norway and so far it seems to me the main range opponent is wet and snowy tarmac, not outdoor temperature. This was a fact with my previous car, a Nissan Leaf, though a much more noticeable disadvantage due to its very limited range from the beginning. My daily routine with the Leaf was to preheat and pre defrost while plugged in and limit the cabin temperature making use of heated seat and steering wheel for comfort.

    • Thanks, we’ve been both very cold (most of the time) and then snowing sometimes. Usually when its snowed its been so much that I don’t end up driving too much. A few times I drove through the storms.

  • Pingback: Can you use Tesla Superchargers for your daily driving? - TESLARATI.com()

  • fred schwieger

    I am from Canada has anyone tested at lets say -30 or -40. that’s some important purchasing info for us

    • I havent, lowest I got to was -9F (-23C). I believe Bjorn has experienced your kind of numbers.

  • Teo

    Hi. The flaw in this article is that rated miles is less than actual miles anyway even in good weather. You say 40% additional range is lost in winter. That’s incorrect. That would have been correct if rated miles was equal to actual miles in summer. It is not.

    • Thanks for your thoughts. I actually often clock in at <300Wh/mi in the summer. My 40,000 mile average is currently 311 and the last 2,200 miles was 294. My 40% number wasn't based on my personal best but the rated miles of 265 and the math from the table above.

      • Teo

        Quote: “I actually often clock in at <300Wh/mi in the summer"

        That doesn't mean anything other than you incorrectly believe 300 Wh/mi is break even point. It is not. 75900/265= 286.4 Wh/mi is when rated range equals to actual range.

        Quote: "My 40% … based on … rated miles of 265"

        That is the problem. Why make a comparison based on a fictional 265 number that you don't achieve anyway? In the UK instead EPA we have NEDC rated range which is 310 miles for S85. If somebody has 155 miles range in winter, is it correct for them to say, "I lose 50% range in winter?" No that is wrong because they never achieved the 310 mile rated range anyway. You don't achieve 265 miles either.

        Let me put things straight. There is no reason to mix in rated range. That will confuse you. The only number you need is Wh/mi.

        In good weather your efficiency is 294 Wh/mi
        In bad weather your efficiency is 357 Wh/mi (On the table you have entered 17 efficiency numbers. The average of these numbers is 357 Wh/mi)

        What is the percentage difference between good and bad weather? Answer: 1-294/357= 0.82= 18%. If you must mix in rated range, here is how to do it correctly:

        In good weather your range is 75900/294= 258 miles.
        In bad weather your range is 75900/357= 213 miles. (The 85 kWh battery has 75900 Wh until rated range is zero)

        Between good and bad weather your range drops 1-213/258= 18%

        By the way, your lifetime average range is 75900/311= 244 miles

      • So your main point is the difference is 18% not 40% when calculated a different way. The 357 you used is an average while the 294 is not and the average in warmer months could be lower. Where’d you get the 75900 from?

  • Teo

    If you put these numbers in the first table, on a Google spreadsheet, I could add some new columns. For example it would be good to add 100% range. In the first row it says you have driven 84 miles and consumed 31.4 kWh. What would be your range if you started with 100% charge and drove until rated range showed zero? Here is how to calculate:

    If 31.4 kWh equals to 84 miles
    Then 75.9 kWh equals to X miles
    X= 75.9*84/31.4= 203 miles.

    There should be a column that shows those range numbers.

  • Stanislav Jaracz

    Thanks for the article. I recognize good effort in quantifying winter penalty in Tesla driving range. However, I am seeing 2 mistakes: 1) Due to initial battery warm up, the total range cannot be extrapolated from partial battery use. Maximum range should be considered as “full discharge” range. 2) Percent decrease in Winter range should be calculated from your own Summer range, not EPA range. Your driving is clearly not EPA cycle.

    • Thanks for your thoughts. I have a set of data i’ve been working on which is a lot more comprehensive that I hope to get out sometime.