So this can pre heat the battery? I am still waiting for the Calgary dealer to confirm this with me. I've only called about 5 times though.....
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Cold. Cold. Cold. Strange / Interesting screen reading.
- Thread starter Garlan Garner
- Start date
So this can pre heat the battery? I am still waiting for the Calgary dealer to confirm this with me. I've only called about 5 times though.....
I welcome a correction if I’m wrong, but I believe there’s nothing that physically disconnects the motor(s) from the rest of the drivetrain when “shifting” to Neutral. Rather, it’s more of an electronically-simulated neutral and the motor(s) is/are basically freewheeling.
Nope. Reverse, neutral and drive are all electronic states. There is no way to mechanically disconnect the motor from the drive wheels. The motors cannot spin without also moving the vehicle.
The fact that neutral exists doesn’t proove there is a neutral gear. It could just allow the motor to spin freely.
I’m not saying there is a neutral gear or not. Just saying the electronic selection of neutral isn’t proof of anything.
I work with stepper and servo motors. You have incredible control over the motors. You can pull as much current as you want with the motor not turning.
Johnny Mac
Member
I’m sorry but preheating your car for 45 minutes is ludicrous. 10 minutes would’ve been enough to get the car up to temperature
Lon12
Member
AlanSubie4Life
Efficiency Obsessed Member
They may well supplement with waste motor heat or heat generated through non-optimal motor drive waveforms, but they also have a Positive Temp Coefficient heater module in the car. I think this is in the part catalog or other public domain diagrams?
I would expect a max of 7.5kWh of use for that scenario (~10kW*45 minutes), but maybe more wattage is possible via other means? So 30 miles. 80 miles is higher than I would expect.
I guess you could check out that bar without any preheating and see how high you can make it go...still...no units on that bar, so a little hard to precisely measure. But if ~335kW is the max it goes to you could estimate? Don’t even know if it is a linear scale though.
2012MS85
Member
I started preheat when I thought we were 5 minutes from wheels up. My wife is clearly more popular, cause it took her another 40 minutes to say goodbye to everyone.
She kept saying “I know; just five more minutes!”And 80F because she had a tiny sexy outfit on that couldn’t have been warm! Wait, maybe that explains why she was more popular last night?!
2012MS85
Member
No snowflake until the drive home. It also didn’t show up on my Tesla app when I preheated (as it used to do a year ago for my 1st S). Maybe the app no longer shows the snowflake (I’m unsure)? Clearly those 3+ hours of extreme outside temps took its toll on my 3. Come to think of it, this was Dory’s first time ever stuck outside for multiple hours, turned off, in such extreme cold. She’s only had her one month birthday recently
FastGTR
Member
I am super interested in your results, just being north of you in Madison. This has been my biggest hold back on getting an M3 -- range anxiety in extreme cold. I don;t think I could make it madison to milwaukee in the cold on a charge.
Are you planning on charging your to the max on Monday and seeing how much you lose? Your observations would be very helpful
2012MS85
Member
I would have thought the same. But my 3 was behaving very different than expected. Perhaps a chunk of that battery usage was what it was using to self-warm its own battery pack while we were at the party? Or did it fail to do that on its own, get cold soaked, and then struggle to reach and maintain that 80F in the cabin for so long? I was shocked when we came out and the range had fallen from about 120 miles when we went into the party, and only 40 when we came out. Had it been an ICE, I would have thought someone had siphoned out my fuel tank! But I don’t think electricity thieves have a way of stealing my kWhs (yet)
I just got back.
There was a Model 3 teardown at Westmont today.
Someone decided that removing the Frunk was something that should have be done first and it went viral with the phrase "get the frunk outta here" - in an Italian sort of way. Constant explosions of the phrase erupted throuout the 15000 sq ft garage all day for 5 hours.
Anywhoo. We pulled the frunk out and set the Model 3 outside. Sure enough...without the frunk. we could hear the front motor with a pretty quiet whine coming from it. Then when we leaned over deep into the frunk area and we could feel the faint spin as we all took a turn touching the front motor. It was certainly warm to the touch.
I suppose it was purposely generating heat as the pumps in the white bottle above it started to come to life as well. Then we heard the fluid running through the battery pack.
From all we experienced the cabin heater is totally separate from the heat generated by the motor spin to heat the battery pack. Now...I wonder if the rear motor does the same for non-dual-motor Model 3's... It would have to in my thoughts.
Anywhoo. "Get the frunk outta here"....LOL
Teslas use fixed reduction gears. There is no transmission, clutch, torque converter, etc. So, mechanical gear changes are not possible. Reverse is done by spinning the motor in the opposite direction as drive. Neutral just lets the car roll, but the motor is also being spun. This is the primary reason that the car must be towed using a flatbed. Tow Mode will allow the car to be pulled slowly for a short amount of time.
My car rolls in drive ( without creep on ) as well. I go through car washes in drive. The car wash will pull my car through in drive.
How was the motor spinning today by itself? It was getting warm to the touch and everything.
I'm confused as to what i saw and what is being said here.
Actually, they can't. They are on a fixed gear that connects them directly to the wheels. (There might be a differential gear to distribute the power to the wheels, but I'm not sure about that)
N only means, the accelerator will do nothing. For reverse, the motors will just spin backwards. For electric motors, that's *way* easier than adding a gear to reverse direction.
ICEs could do it as well, in theory. Ships do it, Lanz Bulldogs could do it...
It’s physically impossible for the motor in a Tesla to spin without the wheels spinning. Similarly, if the wheels are being spun, the motor is also being spun.
I believe it made noise and got warm. Tesla deliberately does that to generate heat which is then used to condition the battery.
But can you generate heat from a motor that isn't spinning?
The axels of the model 3 aren't sitting on the motor. The motor is by itself connected to a differential or something and the heat exchanger plates are sitting on the differential thing.
So...all I know is that the differential thing is heating up some kind of way.
You can see the heat exchanger in this video. He even has the fluid flow marked.
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AlanSubie4Life
Efficiency Obsessed Member
I guess you guys are both right, but @dhanson865 's comment requires him to add "(the wheels will also be spinning)". I am not sure whether that is what he meant. Definitely the motor can spin in neutral, but the wheels also have to turn at 1/9th the rate (I think it's a 9:1 ratio).
Yes, there is a differential. But does not matter for your point. I suppose you could spin the left wheel one way and the right wheel the other way, and then the wheels could be turning and the motor would not be. So that is one way the wheels could be turning without the motor turning (not a practical case of course).
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