# AAA article about EVs loosing 41% range in winter



## webdriverguy (May 25, 2017)

Hi Guys,

AAA released this and tesla is disputing the claim

https://electrek.co/2019/02/07/study-electric-cars-lose-range-temperature-tesla-disputes/

Even thought they tested MS, is anyone seeing 41% reduction in range on their M3 in winter? I am seeing about 15% with 18 inch aero wheels, RWD LR


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## Dogwhistle (Jul 2, 2017)

Yep, that's about right.


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## garsh (Apr 4, 2016)

webdriverguy said:


> Even thought they tested MS, is anyone seeing 41% reduction in range on their M3 in winter?


Only if it's really cold and I'm running the heater. The heater in the Model 3 eats power like crazy. On really cold days, I've seen usage of 380 kW/mile

I experimented on some sub-zero days. I'd bundle up, turn off the heater completely, and run only my seat heater. Doing that, I can get 250 kW/mile, which doesn't seem to be much different than what AWD Model 3s get in the summer. So the efficiency doesn't seem to drop a whole lot in the winter. So that would mean that my winter range reduction is more like 35% on the worst, coldest days when I choose to fully heat the car.

The other thing to consider is that the battery is unable to deliver as much power when it's really cold. That's when you'll see a little snowflake next to your battery mile/percent remaining gauge. On the Charging screen, you'll see that a portion of your "filled" battery will be blue instead of green. This represents the portion of the battery energy that can't be used due to the low temperature. The good news here is that all you have to do to "free up" that part of the battery is to drive the car for a while. The battery will heat up and that energy will once again become available. A short trip won't warm things up enough, but if you're driving for 30-60 minutes or more you should see the blue bar diminish or disappear. I don't know if the AAA took this into account at all.


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## webdriverguy (May 25, 2017)

garsh said:


> Only if it's really cold and I'm running the heater. The heater in the Model 3 eats power like crazy. On really cold days, I've seen usage of 380 kW/mile
> 
> I experimented on some sub-zero days. I'd bundle up, turn off the heater completely, and run only my seat heater. Doing that, I can get 250 kW/mile, which doesn't seem to be much different than what AWD Model 3s get in the summer. So the efficiency doesn't seem to drop a whole lot in the winter. So that would mean that my winter range reduction is more like 35% on the worst, coldest days when I choose to fully heat the car.
> 
> The other thing to consider is that the battery is unable to deliver as much power when it's really cold. That's when you'll see a little snowflake next to your battery mile/percent remaining gauge. On the Charging screen, you'll see that a portion of your "filled" battery will be blue instead of green. This represents the portion of the battery energy that can't be used due to the low temperature. The good news here is that all you have to do to "free up" that part of the battery is to drive the car for a while. The battery will heat up and that energy will once again become available. A short trip won't warm things up enough, but if you're driving for 30-60 minutes or more you should see the blue bar diminish or disappear. I don't know if the AAA took this into account at all.


Plus it's not a apples to apples comparison. MS is a huge car and has high HP. What I hate about these guys is they should have also shown a study with gas cars and then shown a comparison. I have seen a few ppl now say aaa just released something about electric cars and OMG they loose range like crazy and I will never buy one.


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## ADK46 (Aug 4, 2018)

The distinction between power and energy is often lost in these discussions. Nomenclature is extremely important; loosely speaking is deadly to a good understanding. I'll just make up some numbers to illustrate what I mean, and try to use the proper nomenclature. Let the words in _italics_ sink in as you encounter them.

Suppose in warm weather the car can draw 200 kilowatts of _power_ from the battery (about 300 hp, another unit of _power_). If the battery is really cold, it or the system that protects it will limit _power_ draw to 100 kilowatts. Acceleration will be affected. (A more severe restriction is imposed for charging or regen to prevent damage to the battery.)

If the battery has been charged to 70 kilowatt-hours of _energy_, it can supply this _energy_ regardless of temperature. The amount of _energy per unit time_ (the definition of _power_) is reduced, not _energy_. Range is not reduced due to a cold battery, per se. Range is reduced because 1) cold air is more difficult to move through (a relatively small effect), 2) the occupants of the car turn up the heat (a huge effect), and 3) the car may expend _energy_ to warm up the battery (if range is what you want, you don't want the car doing this, though it can mean a longer stop at a supercharger).

All this said, winter range reduction is indeed a bad feature of EVs, and people need to know about it. But please: never give a reduction percentage without stating the temperature. "Winter" means 40°F for some, -20°F for others.


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## garsh (Apr 4, 2016)

webdriverguy said:


> What I hate about these guys is they should have also shown a study with gas cars and then shown a comparison.


Combustion cars will win this particular comparison hands-down. Their engines are so incredibly inefficient that they provide any amount of cabin heating for free. They don't require any additional heater.


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## MelindaV (Apr 2, 2016)

for some perspective on AAA and EVs, in Oregon, the EV rebate that was to go into effect early 2018 was held up and appealed by AAA. The law was recorded, funding was in place and AAA Oregon/Idaho took the state to court (up thru the state supreme court) to block and delayed it until the end of 2018.


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## mswlogo (Oct 8, 2018)

A blanket statement of “Winter” = 41% is stupid. 

It’s different for every degree change and depends a ton on the length of the drive. 

It can be 80% hit if it’s -20F and I drive around the block. Or 10% if it’s 32F and go 100 miles. 

On average for most people I suspect it’s more around 20%. But I guess I’m just as guilty making a blanket statement too, because it’s not just one number. 

That’s on top of what ever else might be impacting efficiency. Sometimes I think folks are already taking a 10% hit on say on driving over 75 mph or sticky tires and putting all inefficiency penalty on cold weather. Were they 100% efficient before Winter? What’s it real-time to? EPA?


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## Love (Sep 13, 2017)

This will be a bit OT but posting this in case someone randomly reads this thread from an internet search, maybe it’s their first visit here, maybe they’re on the fence about an EV purchase and looking for info and articles like this AAA one have caused some hesitance, etc.

Yes, you lose some of your range in the winter, I’ve seen it myself ...though I wouldn’t say 41%, that seems rather high from my own two winter experience with a Tesla Model 3. The solution is simple and elegant...and one that Internal Combustian Engine (ICE) cars can’t do without an extra stop at a gas station every day. When you’re home for the day, plug in!! 

How much did you use? How much is left? Doesn’t matter! Plug in daily and let your car charge to its set percent (I use 80% as my “full” while others vary ). Naturally as we humans are a curious bunch, there are those that love to see usage stats and talk wh/mile, and I myself enjoy the discussion and the “competition” to be the most efficient!! In the end, it only needs to matter as much as you want to care about it.

When I last had an ICE car, I stopped at gas stations, filled them up and just drove, not giving a thought to gasoline until I saw I was low. With an EV you never have to deal with that at all! Get home, plug in, wake up, drive, use your heater, use your seat bacon, use it all on MAX if you want ...and don’t sweat it! Imagine always leaving home with a full tank of “gas.” You can do just that! For example, I leave the house in the morning to go to work, battery is at my “full” Strength of Charge (SOC) of 80%. I get to work and park, slave my day away and then head home. Maybe I head out again for dinner, groceries, errands, etc. before I’m in for the night. So, I’m home, plug in and call it a day. The next day I wake up and walk out to my car and BOOM, it’s 80% again! Did I lose range the day before to the frigid cold temps of winter, high winds, road conditions, wrong tire pressure, acts of dieties? What was my percent of SOC when I got home? I don’t even know...because it’s not important to me and I didn’t look! 

I was full yesterday morning when I left, and am full again today and I’ll be full tomorrow, full the next day, and on and on...
Bliss.


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