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They are just sitting out there, out in the breeze, and they are located far from the coolant inlet to the pack.

If a Bolt and a Model 3 are parked out in the 2°F driveway for 48 hrs, both plugged in and topped up, what would the energy cost differences be for running these TMS systems?

In the AWD versions of the Model 3 and Y, the location of the motor, pumps, and Octovalve is really no further from the battery inlet than the heater and pump on the Bolt.

1613922240180.png 1613922284851.png

They have different battery chemistries, with different temperature requirements, so no simple answer is possible. Note that the 66 kWh battery in the Bolt is also a different chemistry, and apparently requires much less heating than the older 60 kWh chemistry.
 

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I agree, but having the motor stators heat up to heat up the coolant flowing through them is a weird heat source, to me....
Those motors are a large mass of steel, copper, magnets, lube and aluminum.
They are just sitting out there, out in the breeze, and they are located far from the coolant inlet to the pack.

A 'half-a-shoe-box' size 2kW coolant heater tucked in somewhere makes engineering sense, to me... :unsure:

Maybe a Tesla fan can explain why this the way to warm the pack.

So the octovalve is just a fancy coolant director valve?
I thought at first it had something to do with a heat pump system.
Remember you need heat and AC to defog the windows sometimes.

If a Bolt and a Model 3 are parked out in the 2°F driveway for 48 hrs, both plugged in and topped up, what would the energy cost differences be for running these TMS systems?
It will be 2-3 times more costly to keep Tesla plugged at 2°F....
I'm not Tesla fan boy .....but only reason is for eliminating dedicated battery heater is less cost to produce Tesla 3 or Y .
All of my custom projects using Tesla pack's are using dedicated battery heater because it is way more efficient than what Tesla is doing.
On 2021 Tesla 3 and Y now have heat pumps but they are not used unless you call for cabin heating .
Because efficiency at very low weather temperature not good at all and it will need to suck heat out of battery loop to keep heat pump efficiency. Why they eliminated battery heater is out of any logic to me.
Let's not start discussing about door handles that they easily get frozen.
I will most likely get bombarded by Tesla fan's but I can't hide the reality behind owning Tesla EV. In the winter I will always take Bolt any time of the day vs Tesla. Because I have my Tesla completely drained out seating for 3 weeks in the open without being plugged and Bolt didn't experience any problems.
 

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In the AWD versions of the Model 3 and Y, the location of the motor, pumps, and Octovalve is really no further from the battery inlet than the heater and pump on the Bolt.
...
If you say so. what about both motors being used for heating. Is that really a thing?

There is an excellent overview diagram of the Volts various coolant loops.
(I'll track it down and post a link here later... it's a sticky on that forum.)

I would love to see a simple diagram of the Bolts coolant loops.
And the M3 and Y systems. And the S and X while we're at it.
And the Spark EV!

Here's a TMS difference:
The Spark EV and the Bolt uses a 'Hot Plate' method for TMS. (Bottom to top heat exchange.)
The Volt has individual coolant plates between the cells.
Tesla has small tubing snaking through their packs that touches each cell, I believe.

Which is more effective/efficient?
 

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If you say so. what about both motors being used for heating. Is that really a thing?

I would love to see a simple diagram of the Bolts coolant loops.
Good discussion of Model 3 heat here, with links to logs of temps:

.

Here is a diagram I did of the high voltage electronics loop, and the parts diagram of the heater setup. Just add the heater core at the firewall end of those long hoses #4 and #7, and you have it all.

Electronics Coolant Loop.jpg cabin heater .png

The battery heater set up is identical, but the heater is half as big, and much closer to the front of the battery than the pump, and reservoir.

The yellow symbols are the temperature thermistors. The acronyms are GM speak for inverter, onboard charger, and accessory battery charger
 

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Good discussion of Model 3 heat here, with links to logs of temps:

.

Here is a diagram I did of the high voltage electronics loop, and the parts diagram of the heater setup. Just add the heater core at the firewall end of those long hoses #4 and #7, and you have it all.

View attachment 33587 View attachment 33588

The battery heater set up is identical, but the heater is half as big, and much closer to the front of the battery than the pump, and reservoir.

The yellow symbols are the temperature thermistors. The acronyms are GM speak for inverter, onboard charger, and accessory battery charger
Definitely On my Dad's model Y I can see in less than 15-20 minutes while seating still battery raises from -20°C to 50°C.... pushing almost 7 kwh on the stators....while driving and heating up battery it will never hit more than 30°C because of using cabin heater and driving...and while plugged to fast charger it will go all the way to 60°C + before it will stop heating battery and start cooling battery if it goes over 64°C
 

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Definitely On my Dad's model Y I can see in less than 15-20 minutes while seating still battery raises from -20°C to 50°C.... pushing almost 7 kwh on the stators....while driving and heating up battery it will never hit more than 30°C because of using cabin heater and driving...and while plugged to fast charger it will go all the way to 60°C + before it will stop heating battery and start cooling battery if it goes over 64°C
50 - 60C? It sounds too hot for Li-ion battery. Wonder how much reduction in range in cold weather. It must take quite a bit of power to keep temperature this high all the time.

BTW, has anybody tried putting insulation on his bolt's cabin coolant loop hoses? It may help cut down energy loss in winter.

-TL

Sent from my SM-N960U using Tapatalk
 

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50 - 60C? It sounds too hot for Li-ion battery. Wonder how much reduction in range in cold weather. It must take quite a bit of power to keep temperature this high all the time.

BTW, has anybody tried putting insulation on his bolt's cabin coolant loop hoses? It may help cut down energy loss in winter.

-TL

Sent from my SM-N960U using Tapatalk
That is how Tesla chemistry works they love to be on hot side.... Regarding insulation of metal portions pipes yes definitely....but rubber hoses are not needed.... What would benefit is using 1/4 inches coating like they use in truck beads and coat entire bottom of the battery pack.
 

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...... What would benefit is using 1/4 inches coating like they use in truck beads and coat entire bottom of the battery pack.
Not sure if truck bed coating has any R-Value. I thought the pack was built with insulation.
What is forward of the fire wall definitely does not have any.
 

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Not sure if truck bed coating has any R-Value. I thought the pack was built with insulation.
What is forward of the fire wall definitely does not have any.
The insulation in the battery pack consists of white plastic sheets, think thick painter's drop cloth.
 

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The insulation in the battery pack consists of white plastic sheets, think thick painter's drop cloth.
It must have some R-Value. Does the good professor at Weber show this during a teardown of the pack?
Is it used on all sides or is the removable cover insulated with an internal layer?
 

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It must have some R-Value. Does the good professor at Weber show this during a teardown of the pack?
Is it used on all sides or is the removable cover insulated with an internal layer?
The white plastic sheets under the aluminum coolant manifolds are referred to as thermal mats by GM. While they no doubt reduce heat transfer, they are just thin plastic sheets.

Starts at 5:39 in.

 

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The white plastic sheets under the aluminum coolant manifolds are referred to as thermal mats by GM. While they no doubt reduce heat transfer, they are just thin plastic sheets.

Starts at 5:39 in.

Thanks for the link. I'll watch all of these videos someday...
However, it looks like these 'mats' are on top of the 'hot plates'. It's cooling and heating, there professor.... ;)
Don't know why you wouldn't want direct cell contact to the plates to make for better heat or cool conductivity.

To me the question is: What's between the 'hot plates' and the metal bottom plate of the finished pack as installed in the car? The bottom of these hot plates is the area that needs the insulation, and I suspect it has a decent R-Value.
 

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In bolt the big chunk of winter energy loss is the cabin heating. The battery warming stops when the pack reaches 4C ish. Perhaps insulating the hoses in the cabin loop has more meat.

The pack's insulation could certainly be better. But trapped air is not too bad insulation either.

Tesla's pack runs hot. But it also takes energy to keeps it hot in winter. So they gain it back in summer with savings in refrigeration money?

-TL

Sent from my SM-N960U using Tapatalk
 

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Thanks for the link. I'll watch all of these videos someday...
However, it looks like these 'mats' are on top of the 'hot plates'. It's cooling and heating, there professor.... ;)
Don't know why you wouldn't want direct cell contact to the plates to make for better heat or cool conductivity.

To me the question is: What's between the 'hot plates' and the metal bottom plate of the finished pack as installed in the car? The bottom of these hot plates is the area that needs the insulation, and I suspect it has a decent R-Value.
Wow! I watched all those videos, and my brain just "saw" the pads as under the manifolds.. Amazing. So the plastic is supposed to increase the thermal conductivity, like thermal paste under mosfets, and unlike thermal relief pads which decrease heat loss when soldering.
 

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Thanks for the link. I'll watch all of these videos someday...
However, it looks like these 'mats' are on top of the 'hot plates'. It's cooling and heating, there professor.... ;)
Don't know why you wouldn't want direct cell contact to the plates to make for better heat or cool conductivity.

To me the question is: What's between the 'hot plates' and the metal bottom plate of the finished pack as installed in the car? The bottom of these hot plates is the area that needs the insulation, and I suspect it has a decent R-Value.
It has no insulation besides trapped air underneath...if insulation was done...it will definitely help a lot how fast battery is getting cooled down when car was not used.
 

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Wow! I watched all those videos, and my brain just "saw" the pads as under the manifolds.. Amazing. So the plastic is supposed to increase the thermal conductivity, like thermal paste under mosfets, and unlike thermal relief pads which decrease heat loss when soldering.
It also act as barrier when battery heater just starts in cold weather to prevent different rate of expansion between thermal aluminum plates and battery modules...
 

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It has no insulation besides trapped air underneath...if insulation was done...it will definitely help a lot how fast battery is getting cooled down when car was not used.
Really?
Just aluminum thermal plate with a small air gag between it and the bottom overall plate of the battery pack?
Sounds strange.
Sounds almost as wasteful as Tesla's M3/Y roundabout way of generating heat for the pack.
Sounds like the bottom of the pack would be slightly warm to the touch if the TMS is heating full tilt.
Can this lack of insulation be seen in the good professor's videos?
 

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This was instructive. I really had never thought about using metal oxides or other stuff as filler to make plastic thermally conductive.

 

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This was instructive. I really had never thought about using metal oxides or other stuff as filler to make plastic thermally conductive.

Very interesting....is this what we have or something else? I will try to find this conductive plastic sheets from my last teardown on Bolt HV battery..... I do remember when I was taking them out they definitely are something more than just plain plastic.
I guess we are learning something new each day.
 
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