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Preheating battery in cold weather use.

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Just to update, I think I have confirmed that the message "HEATING" with the single heat wave icon probably has nothing to do with battery heating. It looks like this is the message received when the defrost function has finished. With the battery warm from a long drive, I received the 'HEATING" message on the mobile app after leaving climate control (HI Defrost) on for an extended period while the car was parked.

Also, I was finally able to capture what I think was the motor generating heat to warm the battery. I use the 'HOLD" feature instead of creep, and while I was sitting at a red light, I noticed activity on the energy consumption meter. The car had been sitting outside and unplugged for an extended period of time. The impression I get from reading the owners manual is that we can activate battery heating when we see the blue bar icon by plugging in and turning climate control on. I am starting to wonder if above a certain temperature, while you can still get the cold battery status (blue bar), battery heating is really just a function of using the battery to power the cabin heater. The average day time temp I noticed activity on the energy consumption meter was a little colder (-8C), which also showed a much more dramatic effect on regen. Maybe active battery heating when plugged in as suggested in the owners manual occurs at temps below -8C, and it is also possible there is no specific icon for battery heating as seen with Model S and X.

bat heat.jpg
 
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I thought it was discussed elsewhere that the battery heat is only generated while the motor is actually operating (e.g. while driving/accelerating).

Certainly as you draw current from the battery while driving, you are generating heat which definitely warms the battery if it is in a cold state. From my own experience, I believe that this is what is being referred to in the owners manual as a recommendation to warm a cold battery (blue bar and snow flake icon). The battery warms up while powering the cabin heater as opposed to activating battery heating by making use of the motor to generate heat while parked. If you read some of the more technical threads on this topic, instead of having a dedicated heater for the battery, the Model 3's motor can apparently use current to generate heat as a method of rewarming the battery. This issue gets more confusing when trying to compare Model 3 battery performance in relation to local weather patterns because the battery packs temperature will depend more on how you store your car, whether it was plugged in, and how long you have driven. Driving a car that has been plugged in over night in a heated garage will obviously be vastly different from driving a car that has been left out unplugged for several hours in -10C weather in terms of how it will affect regen and battery performance. The image above shows what I believe is the Model 3 software causing the motor to generate heat to warm the battery. The car had been sitting out in -8C weather for about 5 hours, and no regen was available for the first ten minutes after I started driving.
 
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Preconditioning in Cold Weather gives the legend for the heating indicators you see in the app. I've never seen the battery heating icon on my 3, not surprising since it doesn't have a discrete battery heater. The wave icon seems to just be seat heat.

I haven't had any luck getting the battery warm before leaving in the morning, even on 240v and even when moving from 90% to 100% just before leaving to allow charging to heat the battery. Would really appreciate some explicit way to do this as loss of regen is a bit jarring.
 
Preconditioning in Cold Weather gives the legend for the heating indicators you see in the app. I've never seen the battery heating icon on my 3, not surprising since it doesn't have a discrete battery heater. The wave icon seems to just be seat heat.

I haven't had any luck getting the battery warm before leaving in the morning, even on 240v and even when moving from 90% to 100% just before leaving to allow charging to heat the battery. Would really appreciate some explicit way to do this as loss of regen is a bit jarring.

Your link is for the Model S not the 3. I'm just saying that the Model 3 does NOT have that battery icon at this time. Maybe it will appear with later updates, but no one has seen it and reported it on a Model 3 yet.
 
...Driving a car that has been plugged in over night in a heated garage will obviously be vastly different from driving a car that has been left out unplugged for several hours in -10C weather in terms of how it will affect regen and battery performance...

Just a note about that statement. Plugged in really has anything to do with it... now actively CHARGING does. If the car finishes charging 4 hours before you leave in the morning and it is cold in the garage, you WILL have limited regen, and possibly limited battery availability depending on how cold it is. My car finished charging an hour before I left this morning and I had limited regen. Garage temp was about 35F.
 
That’s indicating power consumed by the climate control. Just like S & X, it’s total power consumed. Turn off climate and it’ll go away. If it stays, then you might be seeing battery heat.

@Big Earl, in this case I did as you said to confirm whether there could be anything else causing the energy consumption while the car was in "HOLD". The other point I noticed was that it would only last for about 10 seconds at a time with probably a 15 to 20 second pause in-between. This particular incident was the coldest I think my battery has been as it was the first time there was no regen when I started my drive. I started seeing very limited regen about 10 minutes into the drive. All of these posts I think emphasize why I would like to see more basic information included in the owners manual. It would be useful for me at least if I could just simply read how the car is supposed to perform so that I can more easily determine when it is not. For example, it would be nice to know if I can in fact even warm the Model 3 battery and what I might expect in terms of being able to restore the regen feature. For now it seems, all we can do is trial various things to see what if anything works, and so far I haven't found one that does. Also since the cold weather update, I am consistently getting a flashing yellow charge port light in cold weather, that goes away on its own without any intervention when the car presumably warms up and starts drawing the full current being supplied by the wall connector. In fact I get the exact same behaviour using either of the two 240V chargers I have installed at my house. One is set to deliver 36amps, and the other 30amps. The Model 3 sees this as a possible faulty connection until it warms up, then the caution message disappears and I get the green flashing light. While I am certain that this is not normal behaviour, it is hard to tell if this is something that I should drive the two hours to my nearest service center to have it looked at.

Preconditioning in Cold Weather gives the legend for the heating indicators you see in the app. I've never seen the battery heating icon on my 3, not surprising since it doesn't have a discrete battery heater. The wave icon seems to just be seat heat.

I haven't had any luck getting the battery warm before leaving in the morning, even on 240v and even when moving from 90% to 100% just before leaving to allow charging to heat the battery. Would really appreciate some explicit way to do this as loss of regen is a bit jarring.

@MayorMcCheese, I agree and believe that the elusive battery heating icon does not exist on the 3 yet. Like you, I cannot seem to have any impact on battery function regardless of what I do. It might still be useful to know how and when the Model 3 will start heating the battery as part of the user manual. I am starting to get the impression that it only does this if the car is being used, as in driving.

Just a note about that statement. Plugged in really has anything to do with it... now actively CHARGING does. If the car finishes charging 4 hours before you leave in the morning and it is cold in the garage, you WILL have limited regen, and possibly limited battery availability depending on how cold it is. My car finished charging an hour before I left this morning and I had limited regen. Garage temp was about 35F.

@derotam, you are absolutely right. Timing the battery charge to finish just before you leave in the morning would probably make the most sense if having the warmest battery at the start of the drive is the goal. Having said that, I am still seeing limited regen when I start out in the morning. The Model 3 does unlock regen much quicker mind you when I coordinate charge times with departure times.
 
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That’s indicating power consumed by the climate control. Just like S & X, it’s total power consumed. Turn off climate and it’ll go away. If it stays, then you might be seeing battery heat.

Back to you @Big Earl, I just noticed today that using the cabin heat does cause intermittent power consumption on the touchscreen exactly in the same way that I had previously observed. Now you have me second guessing myself and I can't be sure. I did turn cabin heating off as a check, but can't honestly be sure that I haven't somehow mixed that up with the time I took the picture. As you have probably taken notice, I have been busy trying to work out this battery heating question, and might have mixed something up in the process. Instead of possibly misleading anyone here, disregard my post on power consumption possibly being caused by battery heating. I will post back if that changes with certainty.
 
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I parked my car outside unplugged this morning (08:10am) in -20C weather. When I returned at 14:30pm, the temp had warmed up to -8C. Same blue icon cold battery status as before, but with no regen available. Sat in car for 10 minutes with car turned on and cabin heat off. Nothing, nada, ziltcho on the power consumption meter, making the answer to the question of what caused the power consumption pictured above almost certainly from the cabin heater. I am starting to believe that the concept of the motor using current to generate heat to warm the battery is just a theory, or has not been implemented yet. Would it have to get colder then -20C to turn it on? It doesn't make a lot of sense considering that the car displays the cold battery status at -6C, and has zero regen capabilty when left out for a few hours in -20C. I would assume that given these situations, the car would activate battery heating if it could. My preference for driving while the cold battery status is activated is to use more gentile accelerations. It took about 50 minutes of city driving with MAX cabin heat to regain about 25% regen capability.
On the flip side, I am very happy with the Model 3 RWD winter driving. This car is much more capable then the RWD BMW it replaced in terms of winter driving.
 
I parked my car outside unplugged this morning (08:10am) in -20C weather. When I returned at 14:30pm, the temp had warmed up to -8C. Same blue icon cold battery status as before, but with no regen available. Sat in car for 10 minutes with car turned on and cabin heat off. Nothing, nada, ziltcho on the power consumption meter, making the answer to the question of what caused the power consumption pictured above almost certainly from the cabin heater. I am starting to believe that the concept of the motor using current to generate heat to warm the battery is just a theory, or has not been implemented yet. Would it have to get colder then -20C to turn it on? It doesn't make a lot of sense considering that the car displays the cold battery status at -6C, and has zero regen capabilty when left out for a few hours in -20C. I would assume that given these situations, the car would activate battery heating if it could. My preference for driving while the cold battery status is activated is to use more gentile accelerations. It took about 50 minutes of city driving with MAX cabin heat to regain about 25% regen capability.
On the flip side, I am very happy with the Model 3 RWD winter driving. This car is much more capable then the RWD BMW it replaced in terms of winter driving.
From what I have read batteryheater-feature only occurs during preheating at very low temps. The engine behaves in a diffetent way since it the only generates heat snd not driving torque, that is why it wont work if you sit in your car. If you preheat with car off it will work. If you can replicate the conditions, how much regen will for instance 30 min of preheat give you unplugged? You said in a different post that even after several hours in the cold, you still had some regrn at -5C, but it disappeared when it got colder if not preheated.
 
From what I have read batteryheater-feature only occurs during preheating at very low temps. The engine behaves in a diffetent way since it the only generates heat snd not driving torque, that is why it wont work if you sit in your car. If you preheat with car off it will work. If you can replicate the conditions, how much regen will for instance 30 min of preheat give you unplugged? You said in a different post that even after several hours in the cold, you still had some regrn at -5C, but it disappeared when it got colder if not preheated.

Battery heating on the Model 3 works when it needs to work. It will work even while you're driving if the BMS determines that it's necessary. When it does heat, it only heats enough to meet the minimum temperature requirement for charging and for full propulsion power, then it stops.

Things that can trigger battery heating *if* temperature and operating conditions warrant it: preheating from the app, plugging in to charge or with a charge scheduled for a future time, supercharging, battery temperature drops below minimum safe storage level (deep into the negatives), and finally, just getting in and driving.
 
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Battery heating on the Model 3 works when it needs to work. It will work even while you're driving if the BMS determines that it's necessary. When it does heat, it only heats enough to meet the minimum temperature requirement for charging and for full propulsion power, then it stops.

Things that can trigger battery heating *if* temperature and operating conditions warrant it: preheating from the app, plugging in to charge or with a charge scheduled for a future time, supercharging, battery temperature drops below minimum safe storage level (deep into the negatives), and finally, just getting in and driving.
To clarify, I forgot to say precharging as one of the conditions. The thing is, if I have understood the M3-motor the right way it cannot be used to generate the 4kW of heat when driving, it will however send what waste heat it has through the coolant-loop and hest the bsttery, just like my Model S does ehrn I disable the batteryheater-module with range mode. It will continiue to do so until you have full regen, but if temps are extremrly low it might not give enough heat to do that. When you charge or preheat the M3 under cold enough conditions the motor will produce up to 4kW of waste heat for the battery.
 
Battery heating on the Model 3 works when it needs to work. It will work even while you're driving if the BMS determines that it's necessary. When it does heat, it only heats enough to meet the minimum temperature requirement for charging and for full propulsion power, then it stops.

Things that can trigger battery heating *if* temperature and operating conditions warrant it: preheating from the app, plugging in to charge or with a charge scheduled for a future time, supercharging, battery temperature drops below minimum safe storage level (deep into the negatives), and finally, just getting in and driving.

@Big Earl, how sure are you that the Model 3 heats the battery to meet requirements for charging and full propulsion when it needs to? As you know, I am very interested in this topic and tried very hard to get the facts straight as Tesla's printed information in this area is lacking to say the least. What evidence do you have that the battery is being actively heated other then when you drive the car, or what information source are you using to make you believe what you are saying is true? After observing the behaviour of my Model 3 in much colder weather now, I am convinced that the battery is not being actively heated as you are suggesting. In example, after my car sat over night in -20C weather plugged into a Tesla wall connector(240V) in an unheated garage, both the blue snowflake and blue bar were present before my morning drive the next day without preheating the cabin. The car probably finished the preset 90% SOC cycle around 20:30 the previous day after it was plugged in. So it sat plugged in fully charged from around 20:30 until 08:00 the next morning. Clearly the battery in this case was not heated to allow full propulsion as indicated by the blue icons. I have seen no sign that anything else is happening when you preheat the car other then the car itself heats up. In other words, there is no icon to indicate battery heating like in the Model S and X regardless of the steps or sequence used.

On the flip side, I am much more comfortable driving the Model 3 in cold weather now after realizing that it still performs very well and extreme cold weather is probably a lot less damaging then extreme warm weather. So why is this important, and why should Tesla clarify this issue? The issues IMO revolve around owner convenience related to recharging periods, and to a lesser extent, regenerative braking. Even in -10C, the owner would have to preheat for an extended period of time, or require a lengthy drive to sufficiently heat the battery for fast charging. In most of my daily use cases thus far, it is not really an issue for me as I am able to drive my car long enough to heat the battery and plug my car in when I arrive home. But what about the people that have a short drive to work, and then have no access to power while there? And what if I were traveling to take a ski trip for example, I can also see the potential scenario where my car could be in a low state of charge while being exposed to very low temperatures at the same time. I should be able to decide to utilize the limited power available to just heat the battery as opposed to having to heat the entire car. If I need to make it to a supercharger 25 km away, I might want to avoid heating the cabin at that time. I can always warm the cars interior when I am attached to a charger, but I would probably in most cases prefer not to have sit for additional time at a supercharger waiting for the battery to heat up. I see not being able to control this aspect of the Model 3 as limiting in terms of how I would like to manage my car. Some people don't like to let the gas tank in their car go below half, and I see being able to control battery heating even when the car is unplugged as potentially important to my use of the car. Maybe all it would require is for the Tesla mobile app to show battery pack temp, and for Tesla to clarify optimal temps for fast charging. But if the Model 3 really is capable of actively heating the battery, I think Tesla could dispel a lot of confusion on the matter if they would provide both the necessary printed information and a visible way in the mobile app for the owner to understand this, .
 
@Big Earl, how sure are you that the Model 3 heats the battery to meet requirements for charging and full propulsion when it needs to? As you know, I am very interested in this topic and tried very hard to get the facts straight as Tesla's printed information in this area is lacking to say the least. What evidence do you have that the battery is being actively heated other then when you drive the car, or what information source are you using to make you believe what you are saying is true? After observing the behaviour of my Model 3 in much colder weather now, I am convinced that the battery is not being actively heated as you are suggesting. In example, after my car sat over night in -20C weather plugged into a Tesla wall connector(240V) in an unheated garage, both the blue snowflake and blue bar were present before my morning drive the next day without preheating the cabin. The car probably finished the preset 90% SOC cycle around 20:30 the previous day after it was plugged in. So it sat plugged in fully charged from around 20:30 until 08:00 the next morning. Clearly the battery in this case was not heated to allow full propulsion as indicated by the blue icons. I have seen no sign that anything else is happening when you preheat the car other then the car itself heats up. In other words, there is no icon to indicate battery heating like in the Model S and X regardless of the steps or sequence used.

On the flip side, I am much more comfortable driving the Model 3 in cold weather now after realizing that it still performs very well and extreme cold weather is probably a lot less damaging then extreme warm weather. So why is this important, and why should Tesla clarify this issue? The issues IMO revolve around owner convenience related to recharging periods, and to a lesser extent, regenerative braking. Even in -10C, the owner would have to preheat for an extended period of time, or require a lengthy drive to sufficiently heat the battery for fast charging. In most of my daily use cases thus far, it is not really an issue for me as I am able to drive my car long enough to heat the battery and plug my car in when I arrive home. But what about the people that have a short drive to work, and then have no access to power while there? And what if I were traveling to take a ski trip for example, I can also see the potential scenario where my car could be in a low state of charge while being exposed to very low temperatures at the same time. I should be able to decide to utilize the limited power available to just heat the battery as opposed to having to heat the entire car. If I need to make it to a supercharger 25 km away, I might want to avoid heating the cabin at that time. I can always warm the cars interior when I am attached to a charger, but I would probably in most cases prefer not to have sit for additional time at a supercharger waiting for the battery to heat up. I see not being able to control this aspect of the Model 3 as limiting in terms of how I would like to manage my car. Some people don't like to let the gas tank in their car go below half, and I see being able to control battery heating even when the car is unplugged as potentially important to my use of the car. Maybe all it would require is for the Tesla mobile app to show battery pack temp, and for Tesla to clarify optimal temps for fast charging. But if the Model 3 really is capable of actively heating the battery, I think Tesla could dispel a lot of confusion on the matter if they would provide both the necessary printed information and a visible way in the mobile app for the owner to understand this, .

Blue snowflake doesn't mean lack of propulsion, just loss of capacity. Loss of propulsion would show up as dots on right side of the regen/power bar.

There was someone else I think somewhere on these forums that had seen wall power draw in cold temps when car was not charging or pre-heating.
 
To clarify, I forgot to say precharging as one of the conditions. The thing is, if I have understood the M3-motor the right way it cannot be used to generate the 4kW of heat when driving, it will however send what waste heat it has through the coolant-loop and hest the bsttery, just like my Model S does ehrn I disable the batteryheater-module with range mode. It will continiue to do so until you have full regen, but if temps are extremrly low it might not give enough heat to do that. When you charge or preheat the M3 under cold enough conditions the motor will produce up to 4kW of waste heat for the battery.

In temperatures down to 0F (the lowest I've tested), the car will use 2.5 kW to heat the battery. I assume it can increase that to 4 kW if temperatures are colder and it isn't seeing the temperature rise it expects. That may or may not actually be the case. It can generate extra heat while driving and in some conditions, the center display will show a message saying "Battery is heating: power will improve as you drive."

None of the Teslas will use battery heating to bring the pack up to a temperature where you can do full regen. Model S & X stop heating at about 30 kW regen/charge available, which is around 8-10C. The exact battery temperature setpoints vary based on a number of conditions that I don't fully understand.

Model 3 is kind of like the S & X in range mode: when preconditioning, the battery is only heated to a level that provides full propulsion as opposed to being heated to a point that allows a certain amount of regen. When plugged in and charging, it will heat to a level that allows for charging.
 
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Blue snowflake doesn't mean lack of propulsion, just loss of capacity. Loss of propulsion would show up as dots on right side of the regen/power bar.

There was someone else I think somewhere on these forums that had seen wall power draw in cold temps when car was not charging or pre-heating.

In temperatures down to 0F (the lowest I've tested), the car will use 2.5 kW to heat the battery. I assume it can increase that to 4 kW if temperatures are colder and it isn't seeing the temperature rise it expects. That may or may not actually be the case. It can generate extra heat while driving and in some conditions, the center display will show a message saying "Battery is heating: power will improve as you drive."

None of the Teslas will use battery heating to bring the pack up to a temperature where you can do full regen. Model S & X stop heating at about 30 kW regen/charge available, which is around 8-10C. The exact battery temperature setpoints vary based on a number of conditions that I don't fully understand.

Model 3 is kind of like the S & X in range mode: when preconditioning, the battery is only heated to a level that provides full propulsion as opposed to being heated to a point that allows a certain amount of regen. When plugged in and charging, it will heat to a level that allows for charging.

@derotam, yes the dots were also visible under the green battery icon. Thanks for pointing that out, I should have mentioned it the first time around. After several weeks of very cold weather, I have given up trying to find any indication that the car is somehow heating the battery. And I am left with the understanding that the car has no such capability.

@Big Earl, how are you able to confirm that the battery is being heated? I have followed my car down to temps <-20C with no visible indication in the mobile app, or in car. If you are getting an in car message that the "Battery is heating: power will improve as you drive" at -17C, then there is obviously some difference between our cars because I have not seen this with temps of -29C. In my observations, -6C the car takes very little notice of it other then limiting regen. Below -10C I start to see limited power situations as indicated by the blue icons and dotted line under the battery icon. I would be interested to try and duplicate whatever it is you are doing on this side just to compare. Thanks two both of you for the replies.
 
@derotam, yes the dots were also visible under the green battery icon. Thanks for pointing that out, I should have mentioned it the first time around. After several weeks of very cold weather, I have given up trying to find any indication that the car is somehow heating the battery. And I am left with the understanding that the car has no such capability.

@Big Earl, how are you able to confirm that the battery is being heated? I have followed my car down to temps <-20C with no visible indication in the mobile app, or in car. If you are getting an in car message that the "Battery is heating: power will improve as you drive" at -17C, then there is obviously some difference between our cars because I have not seen this with temps of -29C. In my observations, -6C the car takes very little notice of it other then limiting regen. Below -10C I start to see limited power situations as indicated by the blue icons and dotted line under the battery icon. I would be interested to try and duplicate whatever it is you are doing on this side just to compare. Thanks two both of you for the replies.

I monitored its energy consumption with my Juicebox. I did the same with our roommate's mid-range and got similar results.

If you'd like to check for yourself, park your car outside in the cold overnight. In the morning, plug it in to a charging station that you can monitor energy consumption on (or use an amp meter on the circuit that powers the charging station). Set a charge timer for 30 minutes in the future and watch what happens. You'll see energy consumption from the charger go to about 10 amps (2.5 kW) for a period of time and you can hear the rear motor whine and the coolant pump run. As this is going on, you'll see the blue part of the battery display start to disappear and state of charge will increase even though the vehicle isn't charging.

Here's a link to a photo album with screenshots of my test. https://photos.app.goo.gl/Rry5h4ERiVdgtDzc8