Range Questions after first trip

[Blue Lectroid]

If its due to cold i don't have to worry since this is just a temporary trip, the other 360 days i am in Florida and no cold weather like this

But this effect of 50% range drop is insane for anyone living in this weather.

Cold weather range reduction is (IMHO) the biggest "weakness" of EV's (even more so than charging infrastructure -- at least for the way I use my EV's)...

 

[kort6776]

Does this mean your display is showing a little less than 400, or when you drive your average efficiency means you can go a little less than 400? There is a big difference between the two.

the range you get is because of driving speeds, even in good weather conditions I get no more than 425 miles on long road trips at speeds a bit over 70 MPH. if you want to get closer to the 500 miles of range that is claimed you would need to drive at closer to 55-60 MPH which for most interstate highway driving is not possible.

 

[BS8899]

Cold weather range reduction is (IMHO) the biggest "weakness" of EV's (even more so than charging infrastructure -- at least for the way I use my EV's)...

There is no question cold weather is a challenge to EVs.

That said, I have a few questions to parse this "cold weather" myth:

[1]

 

[BS8899]

There is no question cold weather is a challenge to EVs.

That said, I have a few questions to parse this "cold weather" myth:

[1]

There is no question cold weather is a challenge to EVs.

That said, I have a few questions to parse this "cold weather" myth:

[1] is the effect of temperature, aka cold weather, mostly affect the battery's efficiencies?

[2] does cold weather affect the drive-train's efficiency to any signficant extent?
[3] when driving in cold weather, is there a discernable differences comparing driving short distances and long distance? Specifically, if I drive 300 miles in cold weather, would the battery warm up enough to significantly improve the initial low efficiency?
[4] In cold weather, what if I "precondition" the battery before driving? Yes, I understand it takes power to precondition the battery, but what is the tradeoff?

 

[larrycpa]

Cold weather range reduction is (IMHO) the biggest "weakness" of EV's (even more so than charging infrastructure -- at least for the way I use my EV's)...

I would post that the battery technology will improve and cold weather will be less of an issue. Probably not soon enough, but science March s on.

 

[Knucklehead]

[2] does cold weather affect the drive-train's efficiency to any signficant extent?
[3] when driving in cold weather, is there a discernable differences comparing driving short distances and long distance? Specifically, if I drive 300 miles in cold weather, would the battery warm up enough to significantly improve the initial low efficiency?
[4] In cold weather, what if I "precondition" the battery before driving? Yes, I understand it takes power to precondition the battery, but what is the tradeoff?

[2] - absolutely yes. A cold battery has less usable capacity and less range. Heating the battery takes energy. If you are driving on the highway, the air traveling under the battery cools it off, and if the car tries to keep it warm, it uses more energy.

[3] - depending on the exterior temperature, driving at higher speeds will have a larger impact on battery temperature. So high speed not only kills efficiency from an aerodynamic perspective, but in cold weather, directly draws heat from the battery and reduces efficiency in the "drivetrain".

[4] - preconditioning the battery is required for good driving efficiency in cold weather, IMO. If you start with a warm battery, you use much less energy keeping it warm when driving. The cost is your electricity cost, but if you need as much range as possible, it is worth the cost. Preconditioning the battery when the car is not plugged in will have a minor benefit, but it is still better than trying to keep the battery warm while air is flowing over and under the car.

 

[BS8899]

[2] - absolutely yes. A cold battery has less usable capacity and less range. Heating the battery takes energy. If you are driving on the highway, the air traveling under the battery cools it off, and if the car tries to keep it warm, it uses more energy.

[3] - depending on the exterior temperature, driving at higher speeds will have a larger impact on battery temperature. So high speed not only kills efficiency from an aerodynamic perspective, but in cold weather, directly draws heat from the battery and reduces efficiency in the "drivetrain".

[4] - preconditioning the battery is required for good driving efficiency in cold weather, IMO. If you start with a warm battery, you use much less energy keeping it warm when driving. The cost is your electricity cost, but if you need as much range as possible, it is worth the cost. Preconditioning the battery when the car is not plugged in will have a minor benefit, but it is still better than trying to keep the battery warm while air is flowing over and under the car.

Appreciate your perspectives.

Let me ask for some further calrification:

on [3], drivingshort distances vs driving long distances AT THE SAME SPEED, would the efficiency get progressively better, eventually reaching an an asymptote? Point is, if the batteries will warm up as you drive, getting more effficient, until it reaches an asymptote. Thus, if you look at your cold temp efficiency in the first 30-50 miles, it might be significantly lower thann if you look at the same metrics after 300 miles. That's my hunch.

on [2] I was asking about the drive train (motors, 3 phase converters, etc.) efficiencies, to what extent they are temperature dependent, aside from the batteries. The batteriesare clearly affected because of the thermodynamics of the battery chemistry. But the drive train might be different.

 

[illopp00]

Today i am traveling in Chicago with Temps at 19’s and driving in local streets got me 2.2 mi/kw , is this expected?
My friend who is traveling with me in the same route and same time on Model Y got 3.2.

I see the same occasionally, the Auto climate control is obsessed in cold weather with running the front windshield defrosters, I think this is what uses all the energy.

 

[fisheral]

[2] does cold weather affect the drive-train's efficiency to any signficant extent?
[3] when driving in cold weather, is there a discernable differences comparing driving short distances and long distance? Specifically, if I drive 300 miles in cold weather, would the battery warm up enough to significantly improve the initial low efficiency?
[4] In cold weather, what if I "precondition" the battery before driving? Yes, I understand it takes power to precondition the battery, but what is the tradeoff?

Getting 300 miles would be a dream in cold weather.

 

[BS8899]

Getting 300 miles would be a dream in cold weather.

I agree....I wasn't suggesting it could be done.

I have a 2022 AGT, rated @516 mile range (EPA). Driving highway speed on I-10 (75mph in AZ/70mph in CA) from Phoenix to LA (~400 miles door-to-door), I was never able to do this drive in 60F-75F weather without recharging. I think my AGT on this route can do ~360 miles (100% to 0%) at best!

Obviusly, it will be even less in a Pure/Touring in cold climate.

Mostly, I am trying to decompose the factors that contribute to range-deficits. As noted by many, cold temperature is a big factor and so is the driving speed.

Some users suggest that the batteries might improve (for cold weather performance). Yes, I think they will, but it is a thermodynamic problem, and I think the improvements would be incremental. That said, I am wondering if there are other methods that could optimize the efficicies with the current technologies.

 

[fisheral]

I agree....I wasn't suggesting it could be done.

I have a 2022 AGT, rated @516 mile range (EPA). Driving highway speed on I-10 (75mph in AZ/70mph in CA) from Phoenix to LA (~400 miles door-to-door), I was never able to do this drive in 60F-75F weather without recharging. I think my AGT on this route can do ~360 miles (100% to 0%) at best!

Obviusly, it will be even less in a Pure/Touring in cold climate.

Mostly, I am trying to decompose the factors that contribute to range-deficits. As noted by many, cold temperature is a big factor and so is the driving speed.

Some users suggest that the batteries might improve (for cold weather performance). Yes, I think they will, but it is a thermodynamic problem, and I think the improvements would be incremental. That said, I am wondering if there are other methods that could optimize the efficicies with the current technologies.

I'd love to see any other methods. Currently I drive very conservatively/slow with climate control mostly off in an effort to eke out the miles in the winter. I probably sound like a broken record.

 

[tonybot]

[2] - absolutely yes. A cold battery has less usable capacity and less range. Heating the battery takes energy. If you are driving on the highway, the air traveling under the battery cools it off, and if the car tries to keep it warm, it uses more energy.

[3] - depending on the exterior temperature, driving at higher speeds will have a larger impact on battery temperature. So high speed not only kills efficiency from an aerodynamic perspective, but in cold weather, directly draws heat from the battery and reduces efficiency in the "drivetrain".

[4] - preconditioning the battery is required for good driving efficiency in cold weather, IMO. If you start with a warm battery, you use much less energy keeping it warm when driving. The cost is your electricity cost, but if you need as much range as possible, it is worth the cost. Preconditioning the battery when the car is not plugged in will have a minor benefit, but it is still better than trying to keep the battery warm while air is flowing over and under the car.

Regarding pre-conditioning while plugged in, you can’t precondition the battery while it is being charged right? I know some folks use the term precondition for running the climate system to heat up the car but I thought preconditioning while charging is not an option. Are you suggesting precondition for 30 some minutes and then plug in to top up the charge?

 

[Blue Lectroid]

Regarding pre-conditioning while plugged in, you can’t precondition the battery while it is being charged right? I know some folks use the term precondition for running the climate system to heat up the car but I thought preconditioning while charging is not an option. Are you suggesting precondition for 30 some minutes and then plug in to top up the charge?

If you run the climate at 70 degrees while plugged in for 15-20 minutes you DO “precondition” the battery as the energy used to heat the car will be replaced while plugged in to keep you at the state of charge you have selected. This process warms the battery…call it what you will!

 

[tonybot]

If you run the climate at 70 degrees while plugged in for 15-20 minutes you DO “precondition” the battery as the energy used to heat the car will be replaced while plugged in to keep you at the state of charge you have selected. This process warms the battery…call it what you will!

Basically using the battery and discharge run the climate warms it up and/or cabin air will aid in heating up the battery as well? Just wanted to make sure I understand it correctly. Will also use the API/home assistant to monitor battery temp in the future.

 

[Blue Lectroid]

Basically using the battery and discharge run the climate warms it up and/or cabin air will aid in heating up the battery as well? Just wanted to make sure I understand it correctly. Will also use the API/home assistant to monitor battery temp in the future.

Correct

 

[Blue Lectroid]

This…

 

[Knucklehead]

Appreciate your perspectives.

Let me ask for some further calrification:

on [3], drivingshort distances vs driving long distances AT THE SAME SPEED, would the efficiency get progressively better, eventually reaching an an asymptote? Point is, if the batteries will warm up as you drive, getting more effficient, until it reaches an asymptote. Thus, if you look at your cold temp efficiency in the first 30-50 miles, it might be significantly lower thann if you look at the same metrics after 300 miles. That's my hunch.

on [2] I was asking about the drive train (motors, 3 phase converters, etc.) efficiencies, to what extent they are temperature dependent, aside from the batteries. The batteriesare clearly affected because of the thermodynamics of the battery chemistry. But the drive train might be different.

[3] - using the battery does not create enough heat to offset the cooling effect when the exterior temperature is cold (there is no significant battery heat generated just by driving). Therefore the car has to use energy to heat the battery, reducing efficiency. The longer you drive in very cold temperatures, the colder the battery gets. And it takes more energy to keep it warm, and as it gets colder, the battery capacity decreases. If you start with a warm battery, a short drive will be more efficient than a long drive because the battery cools as you drive. In warm climates you might see better efficiency for long drives because the time spent starting and stopping is a smaller percentage of the total time the car is on.

[2] - IMO the motors and other components might actually be more efficient when it is cold. But the difference is so negligible compared to battery capacity, climate control and aerodynamics, it is just noise. It makes no measurable difference, IMO.

 

[Bonanzajohn]

My P100D Model S Tesla had similar degradation of mileage at 75 MPH as my Lucid GT 520 mile new Air

 

[Blue Lectroid]

My P100D Model S Tesla had similar degradation of mileage at 75 MPH as my Lucid GT 520 mile new Air

No car can find the exponential increase in energy needed to overcome wind resistance at increasing speed.

 

[BS8899]

No car can find the exponential increase in energy needed to overcome wind resistance at increasing speed.

Not to nit-pick....Yes, the air resistance grows at (roughly) the square of the speed of the car. However, if I remember correctly, that's not "exponential growth". I think the correct term is "quadratic growth". If indeed we experience exponential growth in the wind resistance with speed, we won't be going any where.

I am not a mathematician. Someone more knowledgeable should weigh in with his/her opinion.