Interesting finding about Range Mode

[AWDtsla]

It seems the Model 3 has decent regen when the battery is cold. Much more than the Model X at the same temp. I presume the Model 3 chemistry is more tolerant of charging at cold temperatures.

Do you have some evidence for this?

 

[robby]

The Model 3 has the same battery heating abilities. It doesn't have a dedicated heater, but the motor can act has a heater which is effectively the same thing. Not just the heat losses. The Model 3 motor can be run ineffectively on purpose to create extra heat. The motor can even create heat without producing any torque. So even in standstill, the Model 3 can heat the battery just as much as the S or X.

Yes, what I mean is that there is no designated pack heater, not that it cannot heat the pack at all.

It seems an open question at this point what the effectiveness of the Model 3 system is. Do we have any data on how much heat is generated at the motor, and of that, how much reaches the battery pack? Some early owners reported that it takes longer to warm up a cold-soaked 3 battery than it does that of the S or X. Others have commented that Superchargers take longer to reach max speed in cold weather on the 3. These anecdotes suggest to me that there is less thermal energy being distributed to the 3 battery, but of course there could be other explanations. I don't yet have a way to take pack temp readings on our 3 but I will try to do an apples-to-apples comparison with our S once I do.

 

[mongo]

Point of clarification: the drive unit is the heater, not purely the motor sub-component of the drive unit. Unlike the S/X induction motors, I do not think the 3 has rotor cooling. The heat generation likely comes from the inverter using less efficient wave forms or adding runt pulses to increase switching losses...
First Up Close Look At Tesla Model 3 Drive Unit, Battery, Cooling & More

Tesla Model 3 Powertrain Fun. From Carburetors To Carborundum. You've Come A Long Way, Baby! | CleanTechnica

 

[ThosEM]

The Model 3 has the same battery heating abilities. It doesn't have a dedicated heater, but the motor can act has a heater which is effectively the same thing. Not just the heat losses. The Model 3 motor can be run ineffectively on purpose to create extra heat. The motor can even create heat without producing any torque. So even in standstill, the Model 3 can heat the battery just as much as the S or X.

Maybe it *can* heat the battery at rest or slow speeds, but in practice it does not, and there is no switch I can find to enable/disable it, like the Range mode of the Model S. Also, unlike the Model S, limited regeneration persists for hours and hours without a highway speed run, and cannot be countermanded, only tolerated; and it is more tolerable in a lighter car. BUT accompanying that is a reduction of supercharging speed, should one need to do that amid an all-day series of short runs in even cool weather. I'm speaking from experience with that both last spring and currently. I would very much like to see an override / Range switch for when I want fast supercharging now. When supercharging, battery warming to full speed charging and regeneration should be automatic, but is not, or is quite slow.

 

[AWDtsla]

Point of clarification: the drive unit is the heater, not purely the motor sub-component of the drive unit. Unlike the S/X induction motors, I do not think the 3 has rotor cooling. The heat generation likely comes from the inverter using less efficient wave forms or adding runt pulses to increase switching losses...
First Up Close Look At Tesla Model 3 Drive Unit, Battery, Cooling & More

Tesla Model 3 Powertrain Fun. From Carburetors To Carborundum. You've Come A Long Way, Baby! | CleanTechnica

Same as above. Does someone have evidence of the Model 3's pack heating functioning, and power draw estimated?

Datalogs of the car while it's running, for example.

 

[robby]

BUT accompanying that is a reduction of supercharging speed, should one need to do that amid an all-day series of short runs in even cool weather. I'm speaking from experience with that both last spring and currently. I would very much like to see an override / Range switch for when I want fast supercharging now. When supercharging, battery warming to full speed charging and regeneration should be automatic, but is not, or is quite slow.

Has anybody encountered any situation where a Model 3 pack heats as quickly as an S or X pack? It sure sounds like there is a hardware limitation.

 

[scaesare]

I'm not sure if this has been stated (I did a quick thread search), but if Supercharging speeds are based on SOC%, pairing, and battery temperature...perhaps turning on "Range mode" would help reduce charging times if you were driving to a Supercharging with a cold battery. For instance if it were cold outside or you had a short distance to a Supercharger before starting on your journey. I'm amazed at how dismissive some have been about this feature and perhaps a Tesla engineer should explain the pros and cons of its usage.

I've been monitoring canbus temps with range mode on and off. With the cold weather, I think it actually helps that the active cooling of the battery is reduced because driving over 65mph manages to increase the temp naturally, and thereby reduce impedance. You essentially heat the battery for free.

The interesting catch 22 is if your are getting low on SOC, driving slower with range mode on *appears* as though it may actually be a detriment as the battery temp starts to drop and impedance increases, they reducing range. Just an observation.

These posts seem to indicate belief that "normal" mode only cools the battery, and thereby by using range mode to disable that you allowing the battery to warm up.

This is counter to what I believe is widespread understanding (and my observation). The normal operating mode of the car will heat the battery when cold... by the dedicated 6kW pack heater and/or by utilizing waste drive unit heat. Energy usage demonstrates this pretty plainly.

Disabling range mode would decrease the heating capacity available to the pack... and while that will lessen overall energy use (hence extra "range") the pack will be limited for power output and regen (as well as potentially charging rate), for longer.

 

[gavine]

Do you have some evidence for this?

Nothing concrete or official. I have a Model X 90D and Model 3 AWD. Both parked in the same garage. If driven when battery is cold (garage temp), the X seems to have zero regen but the 3 still has a decent amount. My garage is anywhere from 30 to 40 degrees-F. I'm sure the 3 will have no regen when much colder, but at this temperature it has and the X doesn't.

I guess it could be because the 3 is lighter and the same amount of regen available (in kW's) results in a feel of deceleration on the 3 but not on the X because the X has more mass and inertia. Just a thought.

 

[robby]

The 3 also uses 2170s, which have a lower surface area:volume ratio. We should expect them to take longer to cool off and then longer to heat up again compared to 18650s, all else being equal.

 

[mongo]

The 3 also uses 2170s, which have a lower surface area:volume ratio. We should expect them to take longer to cool off and then longer to heat up again compared to 18650s, all else being equal.

Hard to say what is equal though... The thermal mass will definitely be higher for the 2170s. However, the cells could have more active area while using less layers which would reduce the thermal impedance from the inner layers to the outer shell. Then again, each cell is doing more work...

 

[jgs]

Disabling range mode would decrease the heating capacity available to the pack...

Did you mean enabling range mode would decrease the heating capacity? Because the behavior I see. It’s very easy to read off the energy usage meter.

I imagine range mode will still scavenge heat from the drivetrain, even though it disables the pack heater. The fact the battery does eventually warm up during highway driving supports this.

 

[st50maint]

There seems to be some confusing information about range mode.

If the car is cold and I am only going to drive say one mile,
will range mode on or off consume the least energy for that short trip?

 

[ThosEM]

There seems to be some confusing information about range mode.

If the car is cold and I am only going to drive say one mile,
will range mode on or off consume the least energy for that short trip?

Range mode on will suppress battery warming from the energy in the battery, so you'll draw less energy for a short trip that way.

But you won't have much regeneration, so if the trip is down a mountain, you won't gain back much of the energy you used to climb that mountain, which may increase your apparent energy use for the trip.

For a short trip, there won't be much time for the battery to warm up at typical power levels, so there won't be much regeneration difference, and the use will definitely be lower with Range on.

 

[st50maint]

I'm not sure if this has been stated (I did a quick thread search), but if Supercharging speeds are based on SOC%, pairing, and battery temperature...perhaps turning on "Range mode" would help reduce charging times if you were driving to a Supercharging with a cold battery. For instance if it were cold outside or you had a short distance to a Supercharger before starting on your journey. I'm amazed at how dismissive some have been about this feature and perhaps a Tesla engineer should explain the pros and cons of its usage.

Range mode on will suppress battery warming from the energy in the battery, so you'll draw less energy for a short trip that way.

But you won't have much regeneration, so if the trip is down a mountain, you won't gain back much of the energy you used to climb that mountain, which may increase your apparent energy use for the trip.

For a short trip, there won't be much time for the battery to warm up at typical power levels, so there won't be much regeneration difference, and the use will definitely be lower with Range on.

Thanks ThosEM.
That is what I thought but what maximizese said is confusing me.
He suggested turning on range mode while driving to a supercharger to reduce charging time.
If range mode does not heat the battery why would supercharging times be reduced?
What am I missing?

 

[supratachophobia]

Thanks ThosEM.
That is what I thought but what maximizese said is confusing me.
He suggested turning on range mode while driving to a supercharger to reduce charging time.
If range mode does not heat the battery why would supercharging times be reduced?
What am I missing?

This is what I did yesterday. I had a 7hr trip and used Range Mode. I observed the battery slowly increasing in temperature as I drove more. Exterior temp started out at 15' F and then dropped to 1'. It was fairly easy to see that as I drove slower (less then 65mph), pack heat would taper off and even start to reduce. Turning off range mode about 20 miles out from the supercharger, I saw the battery just continue to increase in temp beyond the threshholds observed with Range Mode on. I did this for supercharging since warm batteries charge faster it seems. And the initial supercharging rates were around 90-105kwh, when I know that a cold battery sits around 50-60kwh until the pack warms up. Now, what exact temperature threshhold defines a "hot" pack and "cold" pack? I do not know. Maybe 74-76' F since that seems to be the happy place for Li-Ion.

 

[scaesare]

Did you mean enabling range mode would decrease the heating capacity? Because the behavior I see. It’s very easy to read off the energy usage meter.

I imagine range mode will still scavenge heat from the drivetrain, even though it disables the pack heater. The fact the battery does eventually warm up during highway driving supports this.

Yup... thanks for catching that.

 

[jgs]

Thanks ThosEM.
That is what I thought but what maximizese said is confusing me.
He suggested turning on range mode while driving to a supercharger to reduce charging time.
If range mode does not heat the battery why would supercharging times be reduced?
What am I missing?

You’re missing nothing. The person you quoted is confused.

 

[maximizese]

You’re missing nothing. The person you quoted is confused.

Well now I'm more confused. The first few posts of this thread indicate that range mode on seems to warm the battery by sending warmer fluid (100F)into the battery with cooler fluid leaving the battery. Turning off range mode would reduce the fluid temperature going to the battery. So I was under the impression that Range Mode on meant a warmer battery created by the inverter/drive unit and disabling of the battery heater, and that Range Mode off meant lower battery temperature by utilization of the battery warmer. I'm not sure which Range Mode settings yields a warmer battery and which mode warms the battery faster, but sounds like Range Mode on means a warmer battery.

 

[AWDtsla]

Well now I'm more confused. The first few posts of this thread indicate that range mode on seems to warm the battery by sending warmer fluid (100F)into the battery with cooler fluid leaving the battery. Turning off range mode would reduce the fluid temperature going to the battery. So I was under the impression that Range Mode on meant a warmer battery created by the inverter/drive unit and disabling of the battery heater, and that Range Mode off meant lower battery temperature by utilization of the battery warmer. I'm not sure which Range Mode settings yields a warmer battery and which mode warms the battery faster, but sounds like Range Mode on means a warmer battery.

Not in my car. Only way to confirm is to get a CAN bus reader. No matter what I do, the passive heating target always seems to be ~42C.

 

[jgs]

Well now I'm more confused. The first few posts of this thread indicate that range mode on seems to warm the battery by sending warmer fluid (100F)into the battery with cooler fluid leaving the battery.

Keep in mind the OP is in Orange County, is talking about warm weather driving, and closes with:

I did read that Range Mode will prevent the battery heater (a separate energy sucking electrical heater) from coming on, which ends up being counter productive when the car is charging and plenty of power would be available.

That’s the part that’s relevant to cold weather driving.

The key is that RM reduces (eliminates?) active heating or cooling of the battery. The fluid circulation you’re referring to is passive in the sense of not consuming additional energy to run a resistance heater or AC compressor.