HOT Teslas in Cold Weather

[4701]

So all this cold weather talk is making me nervous. I live in northern Minnesota where we may see winter temperatures below -20°F. We may also get stretches where the temperature won’t rise above 0°F for several days. I’ve always been under the impression that if my model 3 were parked and charging that the battery would be maintained at some optimum temperature regardless of outside temperature. Does anyone know if there are any official environmental operational parameters that are specified for the model 3?

Don't worry. EV batteries care little about what is the momentary temperature (during clear night sky for example). It takes longer to cool down that much. Take the average for 24h. That would be more relevant (if you did not drive for the whole day).
EV's do heat their batteries when it get really really cold (like you just said, below 0*F for days). For a week they can handle being unplugged. If they are plugged in, battery juice will not be used.

This is how EV batteries react to cold. They can be slightly different due to different chemistries and manufacturer settings:
20*C normal behaviour (Tesla will get ludicrous performance only when battery hotter than that)
10*C slightly reduced charge acceptance, that means regen might not be fully available, fast charging will be limited in speed
0*C Tesla - charge acceptance almost gone. Vehicle heats the pack for optimal results during preheat and driving.
0*C Leaf - regen slightly limited. Fast charging slow. Battery will heat up 10*C after an hour of driving.
-10*C Tesla - regen not available. Power output limited. Vehicle will aggressively heat the pack during preheat/driving.
-10*C Leaf - regen almost not available, power output almost not limited (if charge state is not low). Fast charging is very slow.
-20*C Tesla - regen not available, power output likely very limited. Vehicle will heat the pack and better performance is expected within 10 minutes. No certain data is available, battery heater might not be used down to this temperature when vehicle parked.
-20*C Leaf - regen not available, power heavily reduced. Battery heater is operated if temperature get's down to this. If state of charge drops below 30%, heating is stopped and temperature might drop.
-30*C - Car will not drive. Car will not charge. Car will activate battery heater if plugged in. This temperature is not reached if vehicle is plugged in. This temperature will be reached if vehicle is not plugged in long enough and battery state of charge drops (to10-30%) due to battery heater consuming energy.

Also, it's your first post over 1½ years??

 

[JWardell]

I haven't seen much info from our current Model 3 owners regarding cold weather effects so I wanted to reach out and summarize what I've seen in my Model X and see how it compares to the Model 3. I know several of the current Model 3 owners are in warmer weather climates but I've noticed changes that should be occurring even at about 50 degrees.

Starting at about 45-50 degrees, the regen becomes significantly limited (about 50%) when driving a "cold" car - such as parked outside while at work or parked overnight outside if you don't garage. Depending on how cold it is, I've seen it take 30 minutes or more of regular driving before restoring full regen capability. Aside from not capturing as much energy from regen braking, I've become so used to one pedal driving that I need to remind myself frequently to use the brake to slow down when driving with regen braking limited. I see this on my Model X as a dotted yellow line on my power use graph but as I understand it, the Model 3 doesn't yet have a similar power use graph in the UI so I wonder if any current Model 3 owner can comment to any warning that pops up when regen is limited.
View attachment 4042
I have been using the preheat feature a lot more to warm up the car before getting in and it's great but does use up quite a bit of energy. I would estimate that I lose a few "miles" of battery capacity when warming up the car from around 40-50 degree interior temperature. The heated steering wheel is AMAZING. Even when the cabin is already at a comfortable temperature, my hands take longer to warm up and it helps to use the steering wheel heat instead of blasting the cabin heat warmer than necessary. In the Model 3, heating steering should be a PUP option when it gets activated in UI updates.

I have notice a MUCH higher energy consumption when driving in colder weather (about 10-15% more). I assume the heat function of climate control uses up more energy than the cool function but I can't help but wonder if this may also be due to the computer also calculating the effects of the cold weather on the battery. Of course, multiple passengers using heated seats makes the energy consumption go up even more. Again, I can see the average energy use in my Model X display which doesn't yet have a counterpart in the Model 3 UI and previously, the rear heated seats were not activated in the UI.

Because of these increased power consumption/limited regen/cold weather battery effect issues, I have been charging to 80% capacity overnight instead of during warmer weather where a 70% charge for my 40 mile daily commute was my previous norm.

Comments from current Model 3 owners experiencing any of these would be greatly welcome.

You bring up an important point that I had not realized before: Cold temperatures will make the car drive significantly differently, and could present a safety issue. If you are used to Tesla's significant regen and it becomes disabled due to cold battery temperature, the car will unexpectedly not slow down when you lift your foot off the throttle. The extra second or two it takes you to react and use the brake pedal could be precious time.

I would like to see confirmation to the questions...does Tesla keep the pack warmed when plugged in?
Does pre-heating your car using the app also pre-heat the battery?

I know most existing Tesla owners are more fortunate to have garages as well, but with the lower cost of the 3, Tesla will see a much higher percentage of us who must store our cars out in the elements.

Also related: Today's James Cooke vlog, where his S is covered in ice crystals and that frozen charge connector! I'm surprised the charge connectors aren't slightly heated, or they could become frozen to the car in freezing rain.

 

[Brokedoc]

@JWardell, you will be doing outdoor charging in Boston. That will expose you to all the elements and low temps of New England. That will be some challenging weather but I think this link from TMC may give you a little useful info even though the Model 3 is a completely different design. https://teslamotorsclub.com/tmc/threads/understanding-the-battery-heater.59974/. I think you will very much like this thread from your electrical and programming background because there is a link to homebrew ways of viewing Tesla logs via Tesla API.

The battery pack warmer on the S/X uses a lot of energy that is quickly wasted if the weather remains cold so a setting to keep the pack at a minimum temperature is a futile waste. On very cold nights, You should max your charge rate and time charge completion for just before you leave. The heat from charging will warm your pack and melt ice off of the charge port handle. Just to be safe, if you are expecting an ice storm, you may consider skipping charging on that night if you have enough residual range. I suspect the design of the charge port door in the Model 3 may minimize snow and ice buildup compared to the side opening doors on the S/X.

 

[4701]

It is ridiculously expensive to keep the pack fully warmed up (for full regen availability) all the time.
Though I also don't like no customizability of battery temperature while preheating.
Even though Tesla S/X have pack heating, it stops at around 2-8*C. It appears owners are complaining.
I would not like it to stop until 30-40kW of regen is available at 70-80% SOC.
That means if I want to do a long trip far far away in cold weather I actually want to go all in and heat
the pack to at least 10*C, charge it to 95%, preheat the cabin all the way and start my trip with good regen.
Arriving at SC with 20-40% SOC and charge like it's not -15*C outside

Heating frozen surfaces is pretty much double edged sword. It might melt whatever we are heating but
it can't heat forever and likely will freeze due to wind blowing while driving. That melted water will
drip, get stuck in all kinds of cracks and will do even more harm. The best way is to have very slippery
surface which is not warm.

In case of emergency there are spray-on products that melt ice fast.

 

[BigBri]

I'd add that in snow EVs are awesome. My ICE would fishtail around corners even at low speeds. With my leaf I had to do a doughnut before the car even thought of sliding.

 

[JWardell]

@JWardell, you will be doing outdoor charging in Boston. That will expose you to all the elements and low temps of New England. That will be some challenging weather but I think this link from TMC may give you a little useful info even though the Model 3 is a completely different design. https://teslamotorsclub.com/tmc/threads/understanding-the-battery-heater.59974/. I think you will very much like this thread from your electrical and programming background because there is a link to homebrew ways of viewing Tesla logs via Tesla API.

The battery pack warmer on the S/X uses a lot of energy that is quickly wasted if the weather remains cold so a setting to keep the pack at a minimum temperature is a futile waste. On very cold nights, You should max your charge rate and time charge completion for just before you leave. The heat from charging will warm your pack and melt ice off of the charge port handle. Just to be safe, if you are expecting an ice storm, you may consider skipping charging on that night if you have enough residual range. I suspect the design of the charge port door in the Model 3 may minimize snow and ice buildup compared to the side opening doors on the S/X.

The comment there about skiing scares me...drive up to the mountains, and because of the cold, there is no regen coming back down and their battery was down to 16%. Need to save my pennies for long range.

 

[KarenRei]

The comment there about skiing scares me...drive up to the mountains, and because of the cold, there is no regen coming back down and their battery was down to 16%. Need to save my pennies for long range.

Sounds like they had range mode on.

 

[Brokedoc]

Sounds like they had range mode on.

That's definitely a mixed bag on the S/X. Range mode turns off extra power draw like battery heater but when it's cold, the car can't regen. Keep in mind the 3 reportedly doesn't have a separate battery heater and is warmed exclusively with the drivetrain coolant loop so range mode shouldn't affect battery heating as much.

I'm more surprised about the slow power draw from superchargers when the battery is cold. This would make it that much more important to stay at a hotel with a destination charger when visiting cold locations instead of planning on stopping quickly at a supercharger after parked overnight in the cold.

 

[4701]

Keep in mind the 3 reportedly doesn't have a separate battery heater and is warmed exclusively with the drivetrain coolant loop so range mode shouldn't affect battery heating as much.

I'm more surprised about the slow power draw from superchargers when the battery is cold. This would make it that much more important to stay at a hotel with a destination charger when visiting cold locations instead of planning on stopping quickly at a supercharger after parked overnight in the cold.

Model 3, theoretically, could have fixed motor deceleration power at all times. If battery can't accept charge, regen turns into splash of hot coolant right inside the drivetrain at the moment vehicle is slowing down. It should be possible to make unimaginably powerful heater from the drivetrain. And that hot coolant is going to heat the pack. And that will allow regen soon.

EV owners remember that in cold climates it is better to recharge either at the destination with destination charger or before the stay at the last supercharger on the way so that SOC is high when arrived (above 50%). The worst thing is to visit supercharger with cold soaked battery (driven for less than an hour) on the next morning.

 

[NucPower]

I look forward to hearing back from Model 3 owners in really cold weather country. How much range reduction do you get? My Honda Fit EV, with a 20 Kw-hr battery and 80 mile nominal range, would only have about 60 miles range in the morning after charging all night and night temperatures in the 40's. That's a 25% reduction from the "nominal". However, in the summer, I'd sometimes be able to get 100 miles. This is for San Jose, CA. What about Minnesota? N & S Dakota, etc?

 

[DannyB]

I will let you know next January. I live in Ottawa, Ontario and it gets really cold here.
But keep in mind, during the winter months, there are 3 to 4 factors that will lower the range:

1. Cold will affect the battery. Optimal temp is about 20 Celsius.
   
   
2. The cold will require the use of the cabin heater. The heater is a bigger energy draw than the AC.
   
   
3. Cold air is denser, which means more energy is need for the vehicle to punch a hole through the atmosphere. Higher elevations (i.e. Colorado) will actually require slightly less energy because the air is less dense at altitude. That's why Jet fly high.
   
   
4. Winter tires require more energy to turn. (If you install them.)

 

[Brokedoc]

PSA:

Leaves are falling and the weather is turning colder in the northern part of the continent so I thought it would be a good time to revive this thread. Most Model 3 owners have recently gotten their cars during the warmer months and haven't experienced ownership of their EVs in colder weather yet.

A recap of what to watch out for starting with overnight temps starting roughly 50 degrees F:

Your car will have LIMITED REGEN until the battery warms up. Keep this in mind while driving as you will need to use the brakes to make up for the regen limitation.
Your range will decrease significantly (maybe 10-20%) due to use of the heater, heated seats, and decreased battery capacity due to temperature. This decrease in range might not be reflected in the computer if you are going on road trips.
Supercharging speeds are limited during extremely cold battery temps.
Preheating your car while plugged in will use shore power and not affect STATE OF CHARGE of the battery.
Charging the battery warms it up so you can do a little math and calculate a time to start charging overnight and calculate the amperage necessary to finish charging within 30 minutes of the time you expect to leave. Doing this will make sure the battery is warm when you start driving and regen will not be limited.
When going on a road trip, try to stay at a hotel with a destination charger so the car can slowly charge overnight. If you are staying at a hotel without charging and it will be extremely cold, make sure to supercharge BEFORE you go to the hotel as the car will not supercharge first thing in the morning with a very cold battery.

 

[PNWmisty]

PSA:

Leaves are falling and the weather is turning colder in the northern part of the continent so I thought it would be a good time to revive this thread. Most Model 3 owners have recently gotten their cars during the warmer months and haven't experienced ownership of their EVs in colder weather yet.

A recap of what to watch out for starting with overnight temps starting roughly 50 degrees F:

Your car will have LIMITED REGEN until the battery warms up. Keep this in mind while driving as you will need to use the brakes to make up for the regen limitation.
Your range will decrease significantly (maybe 10-20%) due to use of the heater, heated seats, and decreased battery capacity due to temperature. This decrease in range might not be reflected in the computer if you are going on road trips.
Supercharging speeds are limited during extremely cold battery temps.
Preheating your car while plugged in will use shore power and not affect STATE OF CHARGE of the battery.
Charging the battery warms it up so you can do a little math and calculate a time to start charging overnight and calculate the amperage necessary to finish charging within 30 minutes of the time you expect to leave. Doing this will make sure the battery is warm when you start driving and regen will not be limited.
When going on a road trip, try to stay at a hotel with a destination charger so the car can slowly charge overnight. If you are staying at a hotel without charging and it will be extremely cold, make sure to supercharge BEFORE you go to the hotel as the car will not supercharge first thing in the morning with a very cold battery.

I'll add one more:

Keep your car plugged in overnight, even when the car is already at or above the set charge limit. That way you can pre-heat the car in the morning 3-4 minutes before leaving. The reason pre-heating is so important is because the Model 3 uses a Positive Temperature Coefficient (PTC) electric heater core. That simply means it can draw the most watts when the heater core is cold. As it warms up, resistance increases thus decreasing electrical draw. If you keep your car plugged in over-night, whether it needs a charge or not, the high draw portion of the heating cycle (warming the heater core up) can use shore power which will reduce wear and tear on the battery pack, avoid the 10% charge inefficiency penalty (saving energy overall) and prevent most of the range reduction that would be due to heating the heater core up. In the winter it's a good idea to always leave your parking spot with the heater core pre-warmed with shore power because this will benefit even if you like driving in a cool car. And if the humidity is high you will need SOME heat to keep the windows from fogging. After the heater core is hot, electrical consumption of the heater goes way down.

 

[Brokedoc]

On the Model 3, the limited regen indicator is not as obvious as the yellow line in the S/X. The indicator is dashed but still the same gray color. This morning, it was 54 degrees outside and the regen was limited so maybe the temp threshold is 55 or 60 deg F? I’ve also seen in extreme cold weather where acceleration is limited too and regen is nonexistent.

 

[Brokedoc]

I'll add one more:

Keep your car plugged in overnight, even when the car is already at or above the set charge limit. That way you can pre-heat the car in the morning 3-4 minutes before leaving. The reason pre-heating is so important is because the Model 3 uses a Positive Temperature Coefficient (PTC) electric heater core. That simply means it can draw the most watts when the heater core is cold. As it warms up, resistance increases thus decreasing electrical draw. If you keep your car plugged in over-night, whether it needs a charge or not, the high draw portion of the heating cycle (warming the heater core up) can use shore power which will reduce wear and tear on the battery pack, avoid the 10% charge inefficiency penalty (saving energy overall) and prevent most of the range reduction that would be due to heating the heater core up. In the winter it's a good idea to always leave your parking spot with the heater core pre-warmed with shore power because this will benefit even if you like driving in a cool car. And if the humidity is high you will need SOME heat to keep the windows from fogging. After the heater core is hot, electrical consumption of the heater goes way down.

I'm not sure what this means but I did a little experiment this morning. My Model 3 was charged to my preset 80% and I parked overnight outside where the temp was 54 deg F this morning and the regen was limited as the picture above shows.

I moved my car to the garage which isn't heated but is probably around 60 degrees and I plugged it in. As the car was already at 80%, it didn't charge but I turned on the climate control from the app to prewarm the car for 30 minutes on shore power. I didn't see the battery heater symbol appear on my app like I've seen on my X when the battery heater is on. When I left for work, the dashed line on the regen bar was still present but only extended to the middle of "N" instead of under "D". After about 5-10 mins of driving, the dashes on the regen bar disappeared.

My conclusions/questions:
* I think the slight change in the regen bar while the car was plugged in may have been due to the slightly warmer garage or else the battery heating while on shore power is crazy slow.
* It doesn't appear that a battery heater activated when I turned on preheat. Maybe it wasn't cold enough but it was cold enough for the regen limits to be present.
* Maybe there is no battery heater mode from the motor and the battery heating is more of a passive function from waste heat?
* If you want to warm the battery on shore power, it would probably be more effective to time the finishing of charging before you leave the house.

We should get more observations as it gets colder.

 

[FF35]

I’ve owned a Volt and a Bolt but now have the Model 3. Was really surprised to see regen limitied when overnight temps were ~55 degrees. Don’t recall seeing regen limited in the Chevy’s at that temp. After about 20 mins of driving regen was back to 100%.

I only charge at work so leaving home in the morning my car will almost always be ambient temp. Can someone confirm that pre-conditioning will heat the battery pack?

 

[PNWmisty]

I'm not sure what this means but I did a little experiment this morning. My Model 3 was charged to my preset 80% and I parked overnight outside where the temp was 54 deg F this morning and the regen was limited as the picture above shows.

I moved my car to the garage which isn't heated but is probably around 60 degrees and I plugged it in. As the car was already at 80%, it didn't charge but I turned on the climate control from the app to prewarm the car for 30 minutes on shore power. I didn't see the battery heater symbol appear on my app like I've seen on my X when the battery heater is on. When I left for work, the dashed line on the regen bar was still present but only extended to the middle of "N" instead of under "D". After about 5-10 mins of driving, the dashes on the regen bar disappeared.

My conclusions/questions:
* I think the slight change in the regen bar while the car was plugged in may have been due to the slightly warmer garage or else the battery heating while on shore power is crazy slow.
* It doesn't appear that a battery heater activated when I turned on preheat. Maybe it wasn't cold enough but it was cold enough for the regen limits to be present.
* Maybe there is no battery heater mode from the motor and the battery heating is more of a passive function from waste heat?
* If you want to warm the battery on shore power, it would probably be more effective to time the finishing of charging before you leave the house.

We should get more observations as it gets colder.

You may have misunderstood me. The battery heater is not going to come on until it's near the freezing point. I was speaking specifically to warming the heater core (for cabin heat). This is almost a completely separate issue from battery temperature. Even in 40-50 degree weather, the heater core will come on when you start to drive, even if you have the thermostat set to a very cool temperature of 60F. If you do not have your car plugged in, this energy will be drawn from the battery. If you start the heating process while the car is plugged in, all the initial heat will come from shore power (assuming you have level II power). If you only have a 20 amp or less 120V outlet, even the simple act of pre-heating the heater core will draw your battery down in addition to consuming all of your wall current (the heater core has an initial draw of around 6 Kw).

 

[JWardell]

Perhaps I should have posted this in here

https://teslaownersonline.com/threads/limited-regen-after-charging.9101/page-2#post-162523

 

[PNWmisty]

Don’t recall seeing regen limited in the Chevy’s at that temp.

Tesla wants EV's to succeed and it is understood that if battery packs require early replacement, EV's are uneconomical and therefore non-competitive with ICE vehicles. I don't think Chevy wants EV's to succeed and they have a less generous battery warranty. As long as the battery makes it through the warranty period, they don't care. In other words, the Model 3 battery has more sophisticated temperature management to ensure a longer battery life.

I only charge at work so leaving home in the morning my car will almost always be ambient temp. Can someone confirm that pre-conditioning will heat the battery pack?

I've seen no information from Tesla or any other reliable source that pre-heating the cabin will pre-heat the battery. However, if the battery gets cold enough to require heat, it will warm the battery whether you are plugged in or not. It does this by generating heat from the stationary motor and circulating it through the battery pack. It may or may not change the temperature threshold depending upon whether shore power is available and/or the cabin is pre-heating. More clarity on this subject from Tesla would be helpful.

Until we have that, know that it is advantageous to be plugged in in cold weather, even if your battery is at or above the charge limit. Because you can perform the initial pre-heating of the cabin heater core with shore power rather than draw electricity for the initial heater core heating directly from the batteries as you drive off. The only time being plugged in would not be advantageous (assuming it's cool outside) is if you are going to leave the climate control OFF for your entire drive and the battery is not cold enough for the battery heater to come on. But I can't imagine anyone not wanting a LITTLE cabin heat or defrost action if it's cold out. Remember, the heater core will be on even when it's blowing cool air if the ambient temperature is below the set temperature. There is no way to turn it off other than set the temp to "LOW" or turn off the climate control altogether.

 

[Brokedoc]

Another few data points.

Car was 48 degrees this AM outside not plugged in. Turned on the preheat and the inside got all warm and toasty. The heater core heats very quickly in Tesla’s so for comfort purposes, you don’t need to preheat the cabin more than 1-2 mins if you’re trying to save energy. The ambient temp went from 48 deg F to a steady 72 deg F in 4-5 mins but if your a passenger, you feel the warm air much faster than that.

The app looks like this but still no battery indicator showing battery pre warming.