Does Chill mode increase efficiency? Surprisingly, Tesla says yes

Does Chill mode increase efficiency?

This question seems to come up in Tesla circles every so often, and the conventional answer is "no, if you drive exactly the same speeds then acceleration mode does not impact efficiency".

But Tesla has some interesting notes in the manual:

If your vehicle is equipped with a heat pump (to determine if your vehicle has a heat pump, touch Controls > Software > Additional Vehicle Information), you can improve the efficiency of the cabin heating by reducing your selected acceleration mode. This allows the heat pump system to take more heat from the Battery to efficiently heat the cabin, instead of maintaining the Battery's ability to provide peak acceleration performance.

So in weather cold enough to use cabin heating apparently yes it can improve efficiency.

Link to the section for Model 3 (it also exists for S and presumably any heat bump vehicle).

"Tesla Model 3 | E-Cannonball 2018" by JayUny is licensed under CC BY-SA 2.0.
Admin note: Image added for Blog Feed thumbnail

 

[David99]

So I tried initiating 'battery preconditioning' while charging from AC and it won't work. Same with 'Track Mode'. It's not available while parked. Neither from the car nor from the S3XY buttons. So unfortunately this method doesn't work. At least not as conveniently as I hoped. You would have to get in the car, put it in drive and precondition for 20 min, or whatever time it needs. Then plug in again to make up for the lost energy.

 

[voldar]

So I tried initiating 'battery preconditioning' while charging from AC and it won't work. Same with 'Track Mode'. It's not available while parked. Neither from the car nor from the S3XY buttons. So unfortunately this method doesn't work. At least not as conveniently as I hoped. You would have to get in the car, put it in drive and precondition for 20 min, or whatever time it needs. Then plug in again to make up for the lost energy.

Thank you for testing. It is what I was expecting, battery preconditioning for charge doesn't start while the car is plugged in.

I doubt it would be possible, but needs to be tested. AFAIK the preconditioning for charging is only allowed when the car isn’t plugged in. Yes, you could precondition for 20-25 minutes unplugged then you plug the car and refill it, but … needs to be tested.

 

[Cubu]

Holy *sugar*, I’m losing brain cells reading this crap. Go outside before you give yourself an aneurism

 

[voldar]

Holy *sugar*, I’m losing brain cells reading this crap. Go outside before you give yourself an aneurism

Good thing is that it doesn’t look like you have too many. So losing all or losing some doesn’t make it worse.

 

[gsmith123]

Holy *sugar*, I’m losing brain cells reading this crap. Go outside before you give yourself an aneurism

You missed an opportunity to tell everyone to chill out (get it? Chill out? Chill mode? heh). I also didn't expect my thread to turn into a 5 month, 200 reply megachain. But I'm kind of enjoying it.

Nothing like discussing a minor technical detail about EV efficiency to get people really heated up

 

[geordi]

You missed an opportunity to tell everyone to chill out (get it? Chill out? Chill mode? heh). I also didn't expect my thread to turn into a 5 month, 200 reply megachain. But I'm kind of enjoying it.

Nothing like discussing a minor technical detail about EV efficiency to get people really heated up

But getting them heated up uses too much energy to be efficient....

 

[Cubu]

Good thing is that it doesn’t look like you have too many. So losing all or losing some doesn’t make it worse.

After reading your comments, I realize how flat earthers are still around.

 

[Spinkick]

I think they just pushed an update recently that will change battery conditioning based on the supercharger type you are heading to.

You missed an opportunity to tell everyone to chill out (get it? Chill out? Chill mode? heh). I also didn't expect my thread to turn into a 5 month, 200 reply megachain. But I'm kind of enjoying it.

Nothing like discussing a minor technical detail about EV efficiency to get people really heated up

hey, nerds gonna nerd!

 

[Spinkick]

After reading your comments, I realize how flat earthers are still around.

Flat earth is more efficient

 

[gsmith123]

not worth the risk of falling off the edge

 

[sleepydoc]

not worth the risk of falling off the edge

The ledge is just an illusion - you actually end up traveling around the edge to the other side without realizing it

 

[voldar]

After reading your comments, I realize how flat earthers are still around.

Here you are ! Don’t let the door slap you on exit. Don’t forget, Earth is not only flat, it is also tilted.

 

[DrGriz]

Here you are ! Don’t let the door slap you on exit. Don’t forget, Earth is not only flat, it is also tilted.

So if we drive down hill in chill mode on a tilted flat earth at constant velocity, is that more efficient than driving up hill on the same tilted flat earth?

 

[gsmith123]

Hey look we're talking about cars again, we've made it full, ahem, circle (no offense flat earthers)

 

[Spinkick]

not worth the

not worth the risk of falling off the edge

Get the physics PHD back in here. It uses 0 battery due to using stored gravity as energy converted to motion

 

[Spinkick]

Here you are ! Don’t let the door slap you on exit. Don’t forget, Earth is not only flat, it is also tilted.

m'planet

 

[geordi]

The best comment was during an interview with one of these geniuses.... He said this to the reporter:

"There are supporters for a flat earth all around the globe."

Uhm.... Say that again, slower this time.

 

[Icenks]

New to this thread. The geek within me got me very interested so I just want to throw out an idea or 2.

The physicist is right, but in a very ideal condition. That's why it doesn't happen in real life cars.

The reason for ice car that gunning it to speed limit use more gas than accelerating slow is because the engine is optimize to have best mpg when it's cruising at 1500rpm.

The reason gunning your Tesla to speed limit use more battery is because motor is less efficient when there's slip. Meaning that when the rotational speed of the magnetic field and the rotor are different, there's energy wasted. That's the main reason why hard acceleration use more battery.

Of course there are other factors, but I believe that the other factors are much less significant compared to the motor slippage.

I believe that the performance update in 2019 that gives better range and better acceleration are modifications to the magnetic field in the motor to reduce slippage.

 

[voldar]

So if we drive down hill in chill mode on a tilted flat earth at constant velocity, is that more efficient than driving up hill on the same tilted flat earth?

If you go down a slope of a hill, but the Earth is tilted the other way, for you it is like going down, but in fact you are going up. The question should be answered by @Cubu. He’s the "no-brainer" guy.

 

[David99]

The reason gunning your Tesla to speed limit use more battery is because motor is less efficient when there's slip. Meaning that when the rotational speed of the magnetic field and the rotor are different, there's energy wasted. That's the main reason why hard acceleration use more battery.

Of course there are other factors, but I believe that the other factors are much less significant compared to the motor slippage.

I believe that the performance update in 2019 that gives better range and better acceleration are modifications to the magnetic field in the motor to reduce slippage.

Early Teslas had induction motors that have slippage. They are not as efficient, but can roll free without any power. All dual motor Teslas today are running on a permanent magnet reluctance motor in the back, which has no slippage. The rotor follows the magnetic field 1:1. The front motor is an induction motor which most of the time runs free without power. Only when accelerating hard and a little bit when regenerating is the front motor used.

I think the main reason the EV isn't doing so well when pushing it hard is the ohmic losses. Because the voltage is 'constant', the way to increase power is using more Amps. Double the power result in 4 times the losses in all current carrying wires and inside the battery. 4 times the power means 8 times the ohmic losses. That's why some EVs have 800 Volt batteries. It results in half the Ampere which 1/4 of the losses.