Cold weather driving can reduce electric car range over 40 percent, AAA study finds.

  • Thread starter Thread starter Ceetee
  • Start date Start date
  • Replies Replies 42
  • Views Views 6K
Subscribe to Remove Ads
Not to worry. Global warming will solve the problem. <snicker>

IMHO, Fox news is like chastity: it's own reward and punishment.

Bob Wilson
 
The AAA study was conducted with SAE methods and has been widely reported by other news outlets. Much of the range loss is due to cabin and battery heating. Preheating, while attached to a charger, reduces the range loss. The loss is most severe on short trips and especially trips that have multiple extended stops where the EV is parked in the cold without an opportunity to charge. The Tesla was affected in the same manner as the Bolt and Leaf. (Tesla has denied the loss is as severe as the study found.)
 
Certainly the average loss of range due to severe cold weather isn't "over 40%". But the saying "Your mileage may vary", or YMMV, certainly does apply here, in spades!

DaleL already made the points I was going to; that pre-conditioning your car by leaving it plugged in overnight, and the car's computer set to warm the car up before the driver expects to drive the next morning, certainly does reduce the range loss. And there are a lot of variables, such as how long (in minutes or hours) the drive is, and how much the driver uses cabin heat. The longer the drive, the more energy is going to be used heating the cabin.

So it really depend on your driving pattern. I remember a report from some years back, where a Model S driver in Norway said he only lost 20% range on bitterly cold days.

Regarding this recent spate of reports we're seeing repeated all over the internet, of Model 3 drivers losing up to 40% of range, and some even more, up to nearly 50%: I wonder if these are just Tesla bashers spreading FUD, or if there really is something about how the Model 3 is engineered which makes it more susceptible to losing range in very cold weather.

Certainly there are some differences from previous Tesla models. The Model 3 does not have a separate battery heater; it is engineered to intentionally generate waste heat in the motor when needed (and of course only when needed), and that heat is used to warm the battery pack. But I have no idea how much that does or does not impact range.

​
 
Ceetee said:
https://www.foxnews.com/auto/cold-w...ric-car-range-over-40-percent-aaa-study-finds

Updated URL. I did find it surprising that turning on cabin heat for some EVs reduced range by 29%. (I'm guessing gen 1 nissan leafs, and not newer EVs?).
Click to expand...
The new EVs have the same issue. Using a heat pump as opposed to a PTC heater would make a big difference in many areas of the county. The Nissan Leaf offers an optional heat pump for their SV series Leaf model. I believe the Toyota Prius Prime uses a heat pump too.
 
Last edited:
The 40% range loss is not FUD. It seems to be the common number across brands. Both my previous Leaf and current one lost about 40% range when it was bitter cold and you had to have the heater on because of window fogging. The loss is divided mainly between the battery being cold, the heater drawing current. Also cold air is more dense and winter tires probably having more rolling resistance. The missing heat pump from the base model Leaf is not that big a deal. At temperatures where the pump is efficient (above freezing mostly) I am sufficiently comfortable with the heated steering wheel and seat and not using the heater at all. One is dressed for winter after all. Right?
 
Paul K said:
Both my previous Leaf and current one lost about 40% range
Click to expand...
Did either have 'pre-conditioning' that allows the car to use the plug to heat the cabin and battery for 20-30 minutes before leaving?

I have pre-conditioning in both our BMW i3-REx and Prius Prime and this brings the cold weather range loss closer to 10-15%.

Bob Wilson
 
Paul K said:
The 40% range loss is not FUD. It seems to be the common number across brands.
Click to expand...

Okay, I should have been more careful in my wording. It's not that I believe nobody is having that much range loss, it's that I question it is commonplace. Until very recently, I often saw reports of up to ~30% range loss, but very rarely anything higher. Now suddenly, there are a spate of reports of 40-50% range loss, with a suggestion by some that this is commonplace. But maybe that's only for the recent so-called "polar vortex" conditions, where people are experiencing record or near-record lows?

Either that, or there is something different about how the Model 3 is built, which makes it more susceptible to a greater percentage of range loss in cold weather. I hope that's not the case!
​
 
bwilson4web said:
Did either have 'pre-conditioning' that allows the car to use the plug to heat the cabin and battery for 20-30 minutes before leaving?

I have pre-conditioning in both our BMW i3-REx and Prius Prime and this brings the cold weather range loss closer to 10-15%.

Bob Wilson
Click to expand...
Yes. Both Leaf's equipped with a climate control timer that you can pre-heat with. But I'm experimenting with small footprint living. Preheating is still using up household electricity and as such is a no no. Even before EVs I would just get in my cold gasser and drive off very gingerly until the powertrain warmed up. I have no problem getting into a cold vehicle and driving off as long as the windows aren't going to fog. When I do use the heater it's at the lowest setting (18C). You get used to it. Feels strange now getting into a gasser where you can have all that heat blasting away.

And yes PMPU the 40% range loss is when the temp has dropped below -15C (around 0F). Around the freezing point it's a shade over 30% with heater. I think this is part of the discovery process of using EVs. It will be less of a problem in the future if more L3 chargers are around. Just a 5 minute top up could put your battery in a more friendly temperature zone.
 
Paul K said:
But I'm experimenting with small footprint living. Preheating is still using up household electricity and as such is a no no.
Click to expand...

Your objective is admirable, but your reasoning is incorrect. Pre-heating the car will result in a lot more energy saved when driving on a bitterly cold day. If you don't pre-heat the car, then it will just have to pull that much more energy from the wall to charge the battery up again, the next time you charge it up.

Driving with a cold battery wastes a lot of energy.
​
 
Pushmi-Pullyu said:
Your objective is admirable, but your reasoning is incorrect. Pre-heating the car will result in a lot more energy saved when driving on a bitterly cold day. If you don't pre-heat the car, then it will just have to pull that much more energy from the wall to charge the battery up again, the next time you charge it up.

Driving with a cold battery wastes a lot of energy.
​
Click to expand...
We're dealing with two different preheats here. The cabin and the battery. I've experimented on bitter cold nights both plugging in and not plugging in. The battery temp indicator showed the same: Bottom two blue bars only. So I'm going to start off with a cold battery regardless. I don't know whether the other makes have a more aggressive battery heater when plugged in. Just driving the car and "goosing" it a bit brings me to 3 or maybe 4 bars which is a little better for efficiency. (The Goldilocks zone seems to be 6 to 8 bars.) As for cabin heat, it's going to run continuously anyhow just trying to keep up with the heat loss through a metal body and single pane windows. I swear I could heat my house with what it takes to keep a moving car at 18C in -20C temps. You're definitly right about the colder batteries being less efficient. Even accounting for heater use I'm using much more kwh to go the same distance in the winter as summer.
 
Paul K said:
We're dealing with two different preheats here. The cabin and the battery. I've experimented on bitter cold nights both plugging in and not plugging in. The battery temp indicator showed the same: Bottom two blue bars only. So I'm going to start off with a cold battery regardless.
Click to expand...
We have both, a liquid cooled and air cooled, plug-in hybrids. The liquid cooled, BMW i3, runs coolant through the battery and efficiently warms up in winter and cools in summer. The air cooled, Prius Prime, not so well.

One trick for the BMW is:
41SW6qXT1DL.webp

Smaller than a full-size cover, it reduces the windshield and front windows from solar heating. We don't have enough snow and ice to use in the winter.

Bob Wilson
 
Here is the formal report: https://www.aaa.com/AAA/common/AAR/files/AAA-Electric-Vehicle-Range-Testing-Report.pdf

Key Findings:

1. In isolation, hot and cold ambient temperatures resulted in modest reductions of driving range and equivalent fuel economy. Driving range and equivalent fuel economy reductions slightly differ due to the temperature dependency of both the recharge allocation factor (RAF) and battery discharge capacity.
a. On average, an ambient temperature of 20°F resulted in a 12 percent decrease of combined driving range and a 9 percent decrease of combined equivalent fuel economy (when compared to testing conducted at 75°F).
b. On average, an ambient temperature of 95°F resulted in a 4 percent decrease of combined driving range and a 5 percent decrease of combined equivalent fuel economy (when compared to testing conducted at 75°F).​
2. HVAC use results in significant reductions of driving range and equivalent fuel economy.
a. On average, HVAC use at 20°F resulted in a 41 percent decrease of combined driving
range and a 39 percent decrease of combined equivalent fuel economy (when compared to testing conducted at 75°F).
b. On average, an ambient temperature of 95°F resulted in a 17 percent decrease of combined driving range and an 18 percent decrease of combined equivalent fuel economy (when compared to testing conducted at 75°F).​
3. Depending on ambient temperature, HVAC use results in a significant monetary cost increase.​

This looks to be a serious study with attention to detail. I'm still reading it. However, it also shows that "pre-conditioning", heating in the winter and A/C in the summer, can make a significant improvement. The least efficient way is to jump in the car without taking the 20-30 minutes to get the car and cabin ready for the weather conditions.

Bob Wilson
 
Paul K said:
The 40% range loss is not FUD. It seems to be the common number across brands. Both my previous Leaf and current one lost about 40% range when it was bitter cold and you had to have the heater on because of window fogging. The loss is divided mainly between the battery being cold, the heater drawing current. Also cold air is more dense and winter tires probably having more rolling resistance. The missing heat pump from the base model Leaf is not that big a deal. At temperatures where the pump is efficient (above freezing mostly) I am sufficiently comfortable with the heated steering wheel and seat and not using the heater at all. One is dressed for winter after all. Right?
Click to expand...
A missing heat pump means more to me since I live in Western Washington. Our daytime temperatures are above the freezing mark over 90% of the time during the the three winter months.
 
marshall said:
A missing heat pump means more to me since I live in Western Washington. Our daytime temperatures are above the freezing mark over 90% of the time during the the three winter months.
Click to expand...

Certainly a heat pump will be of more benefit to those who live where outside temps rarely get below freezing, even in winter.
​
 
Being pragmatic, even for those living in the colder parts of the US or southern Canada, what portion of the time (and distance) is actually traveled during those months. Even granting 40% is right, and this loss occurs for 4 months in a year, it is about 13% overall extra power per year that you have to spend on, assuming you drive the same amount in the winter months as every other month. In other words you have to charge your battery more often, your range may be limited during that time and you pay a little more in electricity costs and a little lower battery life. Even with 13% more in charging costs, economics still favor EVs. In reality, the overall loss will be much less, and as you get to warmer places, there may be little or no loss. There are things you can do to minimize it and future cars will have other solutions. And even if you have this vehicle in Alaska, I am not sure it will make a very big difference. So while 40% makes good headlines but the devil is in the details and it is not that alarming as people may think.
 
Funny this. This has now become a industry talking point to slam EV.
Heard a analyst today who is a hard boiled person in the thick of fighting nonsense as the battles are always over money which tends to generate nonsense.
No offense to liberals, but a liberal response it to look at the data and explain it away in nice polite terms, nuance it to death.
This guy is defending his book and is probably in all things quite conservative leaning.
Looked the media person straight in the eye confronted with this and said quite sternly....internal combustion engines average 20 percent efficiency. Electric vehicle engines average plus 80 percent.
Said it all that. NO need to add on its worst day with even a 40% loss due to cold, if that could happen, the electric engine is still more efficient by twice some. No other questions on this were made. Nipped it in the bud he did instantly.
Checked it myself I did to gage the analyst. He knows his business, hundred percent correct. In operation freeway and such electric is even more efficient close to 90. Best any IC engine can do auto, Toyota one engine only at 38% Most are in the 20's
It is a total nonsense claim, some is lost not 40 percent, but nevertheless that, means not a whole lot EV and ICE compared.
Again no offense to liberals but when it comes to a fight I know who I will put my money on. Ever watch youtube Antifa against bald head skin head type guys....it can get pathetic to watch or at least the word comes to mind.
If only we could package progressive ideology in conservative ways of acting I think we may have a thing or two.
Liberals resigning over this and that minor things done as kids. DT does what he wants and tells everyone to suck eggs and they do. Not that I like DT, I don't at all, but how many ways can these Barney Fifes figure to shoot themselves in the foot. How about this..yes I was a kid and screwed up and now I am older and know better..works for me. Or this.....I did that yes, and now I must resign. Seems one comes across as a cowardly wimp and the other a adult by my read.
I would put it easier but I am no politician. I did that yes sorry. You want me out go for it next election is two years out, see you then. Till then I run the place not you. Sorry I was a kid, I will try very hard not to be one again.
 
Last edited:
How do these words improve EV performance in cold temperatures:
ron in new mexico said:
. . . No offense to liberals, but . . . conservative leaning . . . no offense to liberals . . . progressive ideology in conservative ways . . . Liberals . . . I am no politician. . . . next election is two years out, see you then.
Click to expand...
Is "2 + 2 =" a partisan political question?

A retired engineer, I love to do engineering things with physics, chemistry, and math. If you want to open a fresh thread to bash politics, perhaps a separate thread?

Bob Wilson
 
bwilson4web said:
How do these words improve EV performance in cold temperatures:

Is "2 + 2 =" a partisan political question?

A retired engineer, I love to do engineering things with physics, chemistry, and math. If you want to open a fresh thread to bash politics, perhaps a separate thread?

Bob Wilson
Click to expand...

No offense bob but this is really just a industry slam. I have surveyed it a bit in the last several days and this is nothing about engineering but all about trying to discount EV.
The first poster referenced the first source, which may be credible but the second fox news is a propaganda outlet. No doubt about that they report things as fact consistently which just are not. On the other side MSNBC does that about half the time as well.They are just not good sources to start off discussions on engineering topics.
I find it interesting none of the engineers amongst us have taken note of the obvious flaw at core to the slam, regardless of loss to cold electric provides always more power all thing considered in comparable terms.
So is my venture into the politic out of place...I say not as fox news is the reference in the initial. Thus it is certainly a political statement.
 
Subscribe to Remove Ads
You must log in or register to reply here.
Back
Top