Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
This site may earn commission on affiliate links.

gnuarm

Model X 100 with 72 amp chargers
In theory kW consumption of the engine can be converted to Wh/mi by dividing by the speed in mi/hr then multiplying by 1000. Sounds great, but what if the kW number displayed on the dash is only the engine usage and doesn't include all the drain from the battery? I say this because I see periods of high consumption on the history graph which don't seem to be displayed in the kW thermometer bar. Nearly every time I start out I get higher power usage for some miles. On the highway it appears that occasionally I see unexplained high usage for a few miles.

I can't account for this by cabin heating. The heater isn't going to come on full blast for 5 minutes then shut off for half an hour. I can only imagine the thermostat has a much shorter duty cycle than that. But the battery heater may well have such a long cycle period. It's not really trying to keep the battery at a given temperature, it's trying to keep it in a range. So when it gets too low the heater comes on and the consumption goes up for a while as the rather large thermal mass of the battery warms up. 6 kW at 60 mph equates to 100 Wh/mi. Enough to show on the history graph even if it is not as much as I am seeing which is often jumps from 400 to 600 Wh/mi.

Anyone know if the battery would need warming while traveling at 60/70 mph?

I'll be going on another trip today. I'll keep a closer eye on this to see if it is just that I'm not noticing hills.
 
How much extra power are you talking about? For the first several minutes of higher consumption, I was wondering if that was caused by battery/motor coolant circulating to test it's working. Compared to ICE, these systems do not need to work from the beginning, but battery heaters could be necessary if the car moves from heated garage to freezing outside, and motor coolant could be necessary if you drive very hard. I guess these systems are tested every day, at the beginning of every drive, to make sure it's working for the whole duration of the drive.

Just my guess.
 
In theory kW consumption of the engine can be converted to Wh/mi by dividing by the speed in mi/hr then multiplying by 1000. Sounds great, but what if the kW number displayed on the dash is only the engine usage and doesn't include all the drain from the battery? I say this because I see periods of high consumption on the history graph which don't seem to be displayed in the kW thermometer bar. Nearly every time I start out I get higher power usage for some miles. On the highway it appears that occasionally I see unexplained high usage for a few miles.

I can't account for this by cabin heating. The heater isn't going to come on full blast for 5 minutes then shut off for half an hour. I can only imagine the thermostat has a much shorter duty cycle than that. But the battery heater may well have such a long cycle period. It's not really trying to keep the battery at a given temperature, it's trying to keep it in a range. So when it gets too low the heater comes on and the consumption goes up for a while as the rather large thermal mass of the battery warms up. 6 kW at 60 mph equates to 100 Wh/mi. Enough to show on the history graph even if it is not as much as I am seeing which is often jumps from 400 to 600 Wh/mi.

Anyone know if the battery would need warming while traveling at 60/70 mph?

I'll be going on another trip today. I'll keep a closer eye on this to see if it is just that I'm not noticing hills.
The "kW thermometer bar" (I don't know the official term, but I'm going to say energy usage meter) only shows three numbers on the consumption side, and even those don't have notches to reference exactly where they are. Further, when you are stopped, with only brake hold and heat or a/c running, you can barely see the power draw registering. Beyond that, each notch is double the last (notches on a 75D are 50, 100, 200, notches on a 100D are 75, 150, 300, and notches on a P100D are 100,200,400), so assuming that the amount of space each kW of draw takes in the energy usage meter is consistently and smoothly reduced from the 0 mark to the 200/300/400 mark, then I don't think you're going to be able to discern the 6kW of battery heater draw while you are moving. That having been said, regarding the battery heater theory, I don't think it runs unless it is needed (i.e. battery below 40 degrees F, which presumably isn't likely to happen while you're moving), so I'm thinking cabin heat may be playing more of a role than you realize. I've seen anecdotal reports that having cabin heat set higher than 68 can drastically affect range, but I don't have any data on that.

Regarding my comment that the battery heater doesn't run unless it is needed, I've heard that, but I also have the following anecdotal data: one day last week when it was 19 degrees F outside, I started a trip with full regen a short period of time after charging and preheating in my garage, and the energy usage meter showed my regen available being reduced about 7 miles into the trip at 55mph. I didn't have heat on, but had to turn it on to clear fog on the windshield. I left it on when I turned it on, and about 4 miles further into the trip, the energy usage meter showed full regen available again. In that time, my average 30 mile usage in the consumption chart was consistent (no evidence of the battery heater running or turning the cabin heat on while set to 66 degrees F causing a spike @ 55mph).
 
I just remembered a scenario I have experienced plenty of times that supports my theory that the battery heater is only run when needed (to protect the battery vs, for instance, to provide full regen). When pre-conditioning, the app will show you an icon to indicate the battery is being heated if it is. I have always left Range Mode OFF, and when I precondition while unplugged after my MX has sat in outside temperatures for 2-6 hours, I have only ever seen that icon indicating the battery is being heated at temperatures lower than 40 degrees F. If it doesn't heat the battery when preconditioning, I can't imagine why it would heat it while driving.

To go off into a segue, I suppose that if you have ludicrous mode and you turn on the Max Battery Power setting, it might heat the battery to a higher temperature, but I'm pretty sure you don't have a P model with ludicrous mode. Also, as you posed this question in another thread, while I don't know it to be a fact, I do believe that the battery heaters are used when you are connected to a supercharger while the battery is cold. This may be incorrect, but I am much more certain that they are used when needed on an HPWC, so if a supercharger is any different, there would likely be a good technical reason. For instance, perhaps because the supercharger is providing a high voltage DC to DC charge, there is no good way to get the low voltage DC required for the battery heaters (for instance, maybe the heaters are 12V and the transformer that would run them and/or charge the 12V system has to be turned off during supercharging).
 
How much extra power are you talking about? For the first several minutes of higher consumption, I was wondering if that was caused by battery/motor coolant circulating to test it's working. Compared to ICE, these systems do not need to work from the beginning, but battery heaters could be necessary if the car moves from heated garage to freezing outside, and motor coolant could be necessary if you drive very hard. I guess these systems are tested every day, at the beginning of every drive, to make sure it's working for the whole duration of the drive.

Just my guess.

600 kW ballpark. My car uses around 300 to 350 on level ground. Of course it goes up considerably on hills, but seldom stays up for 4 miles unless I am clearly in more hilly terrain. I see these square peaks while on the road as well. My working theory is it needs to heat the battery occasionally on freezing cold days, but I haven't tracked it enough to say for sure.
 
  • Like
Reactions: hiroshiy
The "kW thermometer bar" (I don't know the official term, but I'm going to say energy usage meter) only shows three numbers on the consumption side, and even those don't have notches to reference exactly where they are. Further, when you are stopped, with only brake hold and heat or a/c running, you can barely see the power draw registering. Beyond that, each notch is double the last (notches on a 75D are 50, 100, 200, notches on a 100D are 75, 150, 300, and notches on a P100D are 100,200,400), so assuming that the amount of space each kW of draw takes in the energy usage meter is consistently and smoothly reduced from the 0 mark to the 200/300/400 mark, then I don't think you're going to be able to discern the 6kW of battery heater draw while you are moving. That having been said, regarding the battery heater theory, I don't think it runs unless it is needed (i.e. battery below 40 degrees F, which presumably isn't likely to happen while you're moving), so I'm thinking cabin heat may be playing more of a role than you realize. I've seen anecdotal reports that having cabin heat set higher than 68 can drastically affect range, but I don't have any data on that.

Regarding my comment that the battery heater doesn't run unless it is needed, I've heard that, but I also have the following anecdotal data: one day last week when it was 19 degrees F outside, I started a trip with full regen a short period of time after charging and preheating in my garage, and the energy usage meter showed my regen available being reduced about 7 miles into the trip at 55mph. I didn't have heat on, but had to turn it on to clear fog on the windshield. I left it on when I turned it on, and about 4 miles further into the trip, the energy usage meter showed full regen available again. In that time, my average 30 mile usage in the consumption chart was consistent (no evidence of the battery heater running or turning the cabin heat on while set to 66 degrees F causing a spike @ 55mph).

Thanks for the info. You may well be right, that this is about cabin heating. I just expect the cabin heat to be proportional rather than running for 4 minutes continuous, then cutting off for 10 to however many minutes.

I have some complaints with the cabin heating. My left foot gets cold if I leave it in the normal position not far from the door. I only flow air through the lower vents. I wonder if there is a very slight air leak around the door? I can't feel it with my hand at all. When the outside air is freezing I should be able to feel the cold air infiltration if it is enough to bother my leg.
 
The "kW thermometer bar" (I don't know the official term, but I'm going to say energy usage meter) only shows three numbers on the consumption side, and even those don't have notches to reference exactly where they are. Further, when you are stopped, with only brake hold and heat or a/c running, you can barely see the power draw registering. Beyond that, each notch is double the last (notches on a 75D are 50, 100, 200, notches on a 100D are 75, 150, 300, and notches on a P100D are 100,200,400), so assuming that the amount of space each kW of draw takes in the energy usage meter is consistently and smoothly reduced from the 0 mark to the 200/300/400 mark, then I don't think you're going to be able to discern the 6kW of battery heater draw while you are moving.

About the gauge, it would be a power meter, same as horsepower really which is about 1.33 HP/kW.

About the markings, I think you are trying to say it is a logarithmic scale. That would mean equal spaces are equal multipliers. But such a scale can't have a zero or negative values. From 400 to 200 is the same spacing as 200 to 100, then the same spacing again would not take you to zero, but 50 kW. I would appreciate a numeric readout of the power value. I think I've seen that in other electric vehicles. I don't recall which one, either a Honda Civic or a Chevy Bolt maybe, they showed the power to/from all the important functions. Not that it is needed to drive, but it could help to understand where the range is going.
 
600 kW ballpark. My car uses around 300 to 350 on level ground. Of course it goes up considerably on hills, but seldom stays up for 4 miles unless I am clearly in more hilly terrain. I see these square peaks while on the road as well. My working theory is it needs to heat the battery occasionally on freezing cold days, but I haven't tracked it enough to say for sure.

Opps, those numbers should have been kWh/mi... sorry
 
  • Like
Reactions: hiroshiy
I just remembered a scenario I have experienced plenty of times that supports my theory that the battery heater is only run when needed (to protect the battery vs, for instance, to provide full regen). When pre-conditioning, the app will show you an icon to indicate the battery is being heated if it is. I have always left Range Mode OFF, and when I precondition while unplugged after my MX has sat in outside temperatures for 2-6 hours, I have only ever seen that icon indicating the battery is being heated at temperatures lower than 40 degrees F. If it doesn't heat the battery when preconditioning, I can't imagine why it would heat it while driving.

I get what you are saying about preconditioning. But that control is a bit crude and mostly I see these energy use patterns in cold weather. But like I said in another post I will pay more attention to the temperature when I see this in the future. It caught my attention because it often shows up as lasting 4 miles and is very square. Usually hills show up with rather sloped attack and decay edges.

I have observed the functioning of the energy display and it appears to be averaging within a sample period which is about 6 seconds on the highway. I don't know if this period is set by time or by distance. Then the graph is created with data from a 3 sample boxcar average meaning they add up the last three samples and divide by 3 to create the point displayed. If you approach a long hill that starts abruptly and has a consistent rise you will see the consumption curve on the energy display increase for three sample, then level off. To see this held for over 18 seconds requires a fairly long hill. On the downhill you will see the same thing sloping down.

To go off into a segue, I suppose that if you have ludicrous mode and you turn on the Max Battery Power setting, it might heat the battery to a higher temperature, but I'm pretty sure you don't have a P model with ludicrous mode. Also, as you posed this question in another thread, while I don't know it to be a fact, I do believe that the battery heaters are used when you are connected to a supercharger while the battery is cold. This may be incorrect, but I am much more certain that they are used when needed on an HPWC, so if a supercharger is any different, there would likely be a good technical reason. For instance, perhaps because the supercharger is providing a high voltage DC to DC charge, there is no good way to get the low voltage DC required for the battery heaters (for instance, maybe the heaters are 12V and the transformer that would run them and/or charge the 12V system has to be turned off during supercharging).

Be careful what you assume, I do indeed have an X P100DL, but I only use Ludicrous mode when showing off the car. It seems a bit much when driving. I use Sport mode.

I haven't seen any indication of the battery heaters being turned on at Superchargers. Someone pointed out the battery heater is only 6 kW so it takes a long time to heat the battery much. I think they recommend two hours of preconditioning. So that really wouldn't do you a lot of good at Superchargers since you won't be there that long unless the power level drops below 50 kW. I think that's the lowest I've seen at a Supercharger even when cold.
 
Just for reference, my Leaf shows the electronics consumption and will also show a popup such as Turn off A/C for X extra miles.
I don't think that I ever saw the number go above 3.

In the summer, with full A/C and the doors open, 4 hours (showing car at events) would drop the car by 10-20%.
 
Just for reference, my Leaf shows the electronics consumption and will also show a popup such as Turn off A/C for X extra miles.
I don't think that I ever saw the number go above 3.

In the summer, with full A/C and the doors open, 4 hours (showing car at events) would drop the car by 10-20%.

Does the Leaf use the A/C as a heat pump for winter, or does it have straight electric heat? That's the number I'd like to see, blowing the heater solid for say, 10 minutes.
 
Watt-hr/mi is obtained as 1000*kw-hr/mile. The kw-hr number is the integral over time of the power demand just as the mile figure is the integral over time of the speed. The odometer does the integration of the speed and a microprocessor does the integration of the power consumption (of course the odometer integration is done in the same way but we probably have a picture in our minds of the mechanical integrator in an old speedometer - at least the long in the tooth guys do.) Now I think the real question here is as to what goes into the power consumption integrator. I would hope it is the product of the main battery bus voltage and current as this would tell us our 'fuel' efficiency under the conditions at hand. We would expect to see a higher w-h/mi number when the weather is cold requiring the cabin heater to be on and implying more drag at a given speed from higher air density than in warm weather. The necessity to warm the battery would only add to the demand and I'd thus hope to see a larger w-hr/mi figure starting out on a cold morning than I would after the pack is warmed up.

As for when these heating loads come on: that is going to depend on the control algorithm. The cabin heat control algorithm is doubtless PID or fuzzy and the output is doubtless proportional but what is the cycle time? FWIW some baseboard heater thermostats I have in my house have a 15 second cycle but it is entirely possible that the heater may run for five minutes and stay off for half and hour. Depends on the heating load which is effected by things like insolation, wind and outdoor temperature. Same really for the battery pack. There is doubtless an ideal temperature for it and the temperature management system on these cars appears to be very sophisticated to the point where again, the algorithm could be PID or fuzzy and, again, the heater itself may be turned on and off with PWM with the cycle time set to whatever the engineers decided was good.

Then there are other loads like lights, seat warmers, air recirculation fans, valve actuators and so on that work from the 12 V system. Their demands impact the main battery load through the 12 V battery charger. Thus if you turn on the headlights there may be no change in the main battery draw until the 12 V battery discharges to the point where the charger decides to top it up.

As to how these things are displayed I can't comment as I won't get my car till Sat (if they keep to the promised delivery schedule and the stories I see aren't confidence inspiring). Equidistant scale marks at -400, -200, -100, -50, -25, 1, 25, 50, 100, 200, 400 do indeed imply a log magnitude scale. The other consideration with such a display is the time constant which involves not only the question of how often the display is updated but the length of the integration period behind the displayed numbers. Do they represent the last 10 seconds, the last minute etc? Most probably the integrators are 'leaky' representing a long time period but with the recent history more heavily weighted.
 
Here comes a wall...
I have some complaints with the cabin heating. My left foot gets cold if I leave it in the normal position not far from the door. I only flow air through the lower vents. I wonder if there is a very slight air leak around the door? I can't feel it with my hand at all. When the outside air is freezing I should be able to feel the cold air infiltration if it is enough to bother my leg.
As far as I know the door and body are made of aluminum and don't have insulation inside of them. Not to discount your complaint at all, but considering how cold it feels in heated houses as you get closer to builder-grade or single-pane windows, I don't think it's surprising at all that it is colder close to the outside edge of the vehicle than it is near the heating vent.
About the markings, I think you are trying to say it is a logarithmic scale. That would mean equal spaces are equal multipliers. But such a scale can't have a zero or negative values. From 400 to 200 is the same spacing as 200 to 100, then the same spacing again would not take you to zero, but 50 kW.
I see what you're saying about the scale not being fully logarithmic, but that leaves us not knowing what adjustment they made or where, and I still don't think you should be able to tell whether any heating system kicks on or off while driving since my experience shows them only taking a pixel or 2 right next to 0. Even if 0-50/75/100 is linear, I would think a pixel or two of fluctuation wouldn't be uncommon even during cruising on flat land in the summer. However, perhaps my assumption that it is only 1-2 pixels could be wrong if your heater is set to a higher temperature than mine usually is. That having been said, if it is heat, since it's electric, maybe the heating system works similar to the seats, where it kicks on until a certain temperature threshold is met and then kicks off until a separate lower threshold is met. This might explain what you are seeing since it's relatively short periods of time. Also, perhaps I should point out that the 0 to -50 section of the power meter is the same on all S and X models and is arguably a separate scale (still leaving us to hypothesize on linear vs logarithmic).
I have observed the functioning of the energy display and it appears to be averaging within a sample period which is about 6 seconds on the highway. I don't know if this period is set by time or by distance. Then the graph is created with data from a 3 sample boxcar average meaning they add up the last three samples and divide by 3 to create the point displayed. If you approach a long hill that starts abruptly and has a consistent rise you will see the consumption curve on the energy display increase for three sample, then level off. To see this held for over 18 seconds requires a fairly long hill. On the downhill you will see the same thing sloping down.
Since you've gleaned better information in your observations than I have in mine, and perhaps because you have more formal mathematical education, perhaps you could explain what I'm missing here: Odd Consumption "30 Mi Average" Behavior
Be careful what you assume, I do indeed have an X P100DL, but I only use Ludicrous mode when showing off the car. It seems a bit much when driving. I use Sport mode.
I don't have a P model, but IIRC, "Max Battery Power" is only available when in Ludicrous mode, so the fact that you are in sport mode would support my anecdotal evidence that the battery heater is unlikely to be running while you are driving.
 
Here comes a wall...As far as I know the door and body are made of aluminum and don't have insulation inside of them. Not to discount your complaint at all, but considering how cold it feels in heated houses as you get closer to builder-grade or single-pane windows, I don't think it's surprising at all that it is colder close to the outside edge of the vehicle than it is near the heating vent.

What you say is true, but they also have one heating vent for the whole room while a car has a vent next to the other foot which is only a foot or so away. The air circulates pretty well in that area I would think. Even with the other vents closed this happens. I don't turn the fan up much because I don't like the noise.

I see what you're saying about the scale not being fully logarithmic, but that leaves us not knowing what adjustment they made or where, and I still don't think you should be able to tell whether any heating system kicks on or off while driving since my experience shows them only taking a pixel or 2 right next to 0.

Actually, it would be a larger amount of the scale near zero. That's what the log scale does, it magnifies the low end and compresses the high end.

The issue is not that I can't see 6 kW, it's just I can't tell if it is 5 or 6 or even 10 for sure. But I have no doubt when on a level piece of road I'd be able to see 6 kW anywhere in the x to 100 part of the scale.

Even if 0-50/75/100 is linear, I would think a pixel or two of fluctuation wouldn't be uncommon even during cruising on flat land in the summer. However, perhaps my assumption that it is only 1-2 pixels could be wrong if your heater is set to a higher temperature than mine usually is. That having been said, if it is heat, since it's electric, maybe the heating system works similar to the seats, where it kicks on until a certain temperature threshold is met and then kicks off until a separate lower threshold is met.

I expect the heater could be on/off. But I would not expect the cycle to be a half an hour. Try turning off your heat when it's cold out. The car will feel pretty cool in just a few minutes. So the cabin heater likely cycles much faster than what I'm seeing.

This might explain what you are seeing since it's relatively short periods of time. Also, perhaps I should point out that the 0 to -50 section of the power meter is the same on all S and X models and is arguably a separate scale (still leaving us to hypothesize on linear vs logarithmic).Since you've gleaned better information in your observations than I have in mine, and perhaps because you have more formal mathematical education, perhaps you could explain what I'm missing here: Odd Consumption "30 Mi Average" BehaviorI don't have a P model, but IIRC, "Max Battery Power" is only available when in Ludicrous mode, so the fact that you are in sport mode would support my anecdotal evidence that the battery heater is unlikely to be running while you are driving.

No idea. You do seem to understand this stuff well. The point being picked up vs. the point being lost is exactly how you should look at it.

That said, I don't agree that the battery is not heated if you aren't in Ludicrous mode. They apply the battery heater when you precondition and they may or may not heat the battery when running on a cold battery. That is my point. I wonder if the battery is heated enough through self heating on cold days. I know it works better when not too cold (which is not the same as the Ludicrous mode heating for minimum resistance in a drag race), so if the battery gets too cold, even if it's not yet cold enough to warrant a limit on regeneration, I can see them warming up the battery. This may even be a lifespan issue. It's one thing to drive on a cold battery for a short bit, but it might be a more significant factor at higher speeds and longer times.
 
The issue is not that I can't see 6 kW, it's just I can't tell if it is 5 or 6 or even 10 for sure. But I have no doubt when on a level piece of road I'd be able to see 6 kW anywhere in the x to 100 part of the scale.
My point wasn't that it wouldn't be visible, it was that it wouldn't be obvious. More to the point *I* (and therefore presumably you due to the species link and whatnot) couldn't be certain it had changed by that little if I glanced away, it changed that little, and I looked back
I expect the heater could be on/off. But I would not expect the cycle to be a half an hour. Try turning off your heat when it's cold out. The car will feel pretty cool in just a few minutes. So the cabin heater likely cycles much faster than what I'm seeing.
Maybe I misread, but I thought you said 10 minutes in a later post and was operating on that short time frame. Moreover, when you turn the heater off, the air stops circulating, when the element is turned off but the fan continues to run, there is potentially a lot of heat stored in the element and thusly left to distribute.
That said, I don't agree that the battery is not heated if you aren't in Ludicrous mode. They apply the battery heater when you precondition and they may or may not heat the battery when running on a cold battery. That is my point. I wonder if the battery is heated enough through self heating on cold days. I know it works better when not too cold (which is not the same as the Ludicrous mode heating for minimum resistance in a drag race), so if the battery gets too cold, even if it's not yet cold enough to warrant a limit on regeneration, I can see them warming up the battery. This may even be a lifespan issue. It's one thing to drive on a cold battery for a short bit, but it might be a more significant factor at higher speeds and longer times.
As far as I can tell, the battery is only potentially heated in three scenarios:
1) It needs heated because it is so cold that it can't regen at all (discharging could be detrimental without heat)
2) It needs heated in order to allow for faster charging (without waiting for charging waste heat to provide this)
3) It is told to be heated by the max battery power setting

Unfortunately, I have no hard data on any of those points. The anecdotal evidence I have to support those is as follows:

1) Preconditioning from the app only shows the battery heater on when it is extremely cold. The fact that regen can be limited when you park outside at temperatures close to 50 degrees F but preconditioning in the app doesn't show the battery heater active until you are parked outside at temperatures near or below freezing implies that the battery doesn't need to be heated more for driving/discharging just because regen is limited. Further, when the app doesn't show the battery being heated, preconditioning for an hour has no effect on regen vs preconditioning for 15 minutes. While an hour wouldn't be enough time to bring the battery to optimal temperatures with the heaters, the fact that regen doesn't benefit at all beyond a small slice near 0 when battery heating is indicated in the app paired with the fact that the battery heating function was added to preconditioning last year in order to prep the vehicle for driving with some regen implies to me that no additional battery heat is needed for driving/discharging.
2) I don't really know that there is anything that we can observe to confirm this ever happens, but it certainly seems like most people who talk like they have a clue believe this is happening.
3) The manual specifically states that this setting heats and cools the battery for optimal power.

I will point out that I am under the impression that range mode specifically disables the battery heaters. However, it also specifically limits the power available for heating and cooling the cabin. Perhaps try turning on range mode and see how the behavior changes. If it goes away completely and you don't find the cabin cooler, that supports the battery heaters being used when I don't think they would. If the cabin feels the same and the behavior doesn't go away, or if the cabin feels cooler, but the behavior is less extreme and/or more frequent, those supports the cabin heat being the culprit. However, before performing this test, it would be wise to read the manual section covering the range mode setting, because it has been 15 months since I did, and I could be remembering something(s) wrong.
 
Last edited:
My point wasn't that it wouldn't be visible, it was that it wouldn't be obvious. More to the point *I* (and therefore presumably you due to the species link and whatnot) couldn't be certain it had changed by that little if I glanced away, it changed that little, and I looked backMaybe I misread, but I thought you said 10 minutes in a later post and was operating on that short time frame.

Not sure where you are going with this. I can see if the wattage bumps by 6 kW in normal driving. Even with normal driving it isn't stable enough to not vary by a lot more than 6 kW within 10 minutes. The bump I see is in the consumption graph which they mislabel as an energy display.

Moreover, when you turn the heater off, the air stops circulating, when the element is turned off but the fan continues to run, there is potentially a lot of heat stored in the element and thusly left to distribute.

Actually there is very little heat stored in the type of element used in an application like this. It cools rapidly.

As far as I can tell, the battery is only potentially heated in three scenarios:
1) It needs heated because it is so cold that it can't regen at all (discharging could be detrimental without heat)
2) It needs heated in order to allow for faster charging (without waiting for charging waste heat to provide this)
3) It is told to be heated by the max battery power setting

Unfortunately, I have no hard data on any of those points.

Exactly. I am speculating based on my observations. But in each of the conditions above the common element is that the battery needs to be heated. If the battery cools while driving it makes sense it would not wait until the regen is compromised to heat the battery.


The anecdotal evidence I have to support those is as follows:

1) Preconditioning from the app only shows the battery heater on when it is extremely cold. The fact that regen can be limited when you park outside at temperatures close to 50 degrees F but preconditioning in the app doesn't show the battery heater active until you are parked outside at temperatures near or below freezing implies that the battery doesn't need to be heated more for driving/discharging just because regen is limited. Further, when the app doesn't show the battery being heated, preconditioning for an hour has no effect on regen vs preconditioning for 15 minutes. While an hour wouldn't be enough time to bring the battery to optimal temperatures with the heaters, the fact that regen doesn't benefit at all beyond a small slice near 0 when battery heating is indicated in the app paired with the fact that the battery heating function was added to preconditioning last year in order to prep the vehicle for driving with some regen implies to me that no additional battery heat is needed for driving/discharging.
2) I don't really know that there is anything that we can observe to confirm this ever happens, but it certainly seems like most people who talk like they have a clue believe this is happening.
3) The manual specifically states that this setting heats and cools the battery for optimal power.

I don't put as much confidence in your conclusions as you do. The fact that they heat the battery when regen is compromised doesn't mean they don't heat at other times. Next time it is heating the battery for regen I will watch the displays closely to see if I can tell when it shuts off the heater.

I will point out that I am under the impression that range mode specifically disables the battery heaters. However, it also specifically limits the power available for heating and cooling the cabin. Perhaps try turning on range mode and see how the behavior changes. If it goes away completely and you don't find the cabin cooler, that supports the battery heaters being used when I don't think they would. If the cabin feels the same and the behavior doesn't go away, or if the cabin feels cooler, but the behavior is less extreme and/or more frequent, those supports the cabin heat being the culprit. However, before performing this test, it would be wise to read the manual section covering the range mode setting, because it has been 15 months since I did, and I could be remembering something(s) wrong.
 
Not sure where you are going with this. I can see if the wattage bumps by 6 kW in normal driving. Even with normal driving it isn't stable enough to not vary by a lot more than 6 kW within 10 minutes. The bump I see is in the consumption graph which they mislabel as an energy display.
This could be due to wind or, if it's consistent on the same trip, imperceptible inclines and declines in elevation. While I don't think this is thecase, if you are comparing a summer trip to a winter trip vs the peaks and valleys of the same winter trip, then the difference might be explained by the more dense air.
Exactly. I am speculating based on my observations. But in each of the conditions above the common element is that the battery needs to be heated. If the battery cools while driving it makes sense it would not wait until the regen is compromised to heat the battery.

I don't put as much confidence in your conclusions as you do. The fact that they heat the battery when regen is compromised doesn't mean they don't heat at other times. Next time it is heating the battery for regen I will watch the displays closely to see if I can tell when it shuts off the heater.
In both of these responses, you seem to have misunderstood what I am stating. I prefer having full regen available and was looking forward to that with the battery heating being added to preconditioning. Unfortunately, that is not how it worked out. Since preconditioning is implicitly for getting the vehicle ready to drive, I can't understand why it wouldn't heat the battery until full regen was available, but it doesn't, and if it doesn't heat the battery to where full regen is available when it is implicitly preparing the vehicle for driving, then I can't imagine that the battery needs to be warm enough for full regen. If the battery doesn't need to be warm enough for full regen, then I can't fathom a scenario where it would heat the battery while the vehicle is not plugged in and full regen is available (as I infer from full regen availability paired with no option to get that from preconditioning that the battery is already warmer than what necessitates heating). In addition to that, I thought I posted about a trip where I had available regen actually drop while driving. It sounds like you are driving while full regen is available when you are seeing these peaks in the consumption chart. In this case, considering the evidence I just re-hashed, I can't understand why you would think the battery is even possibly being heated, but I don't imagine it merits further discussion without additional data unless I still have an invalid assumption in my logic.