# Cabin Overheat Protection Battery Drain



## jtk00l (May 15, 2018)

Since this feature was added I thought I would let you know what kind of drain this can put on the battery. Today it is 104 degrees here in Dallas Texas and parking in full sun I am getting an average battery drain of 4-5 miles per hour. After 2 hours my battery has gone from 176 miles to 166 miles.

Love the feature but something to keep in mind if you are parking your car on a hot day in full sun for 8 hours.


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## GDN (Oct 30, 2017)

jtk00l said:


> Since this feature was added I thought I would let you know what kind of drain this can put on the battery. Today it is 104 degrees here in Dallas Texas and parking in full sun I am getting an average battery drain of 4-5 miles per hour. After 2 hours my battery has gone from 176 miles to 166 miles.
> 
> Love the feature but something to keep in mind if you are parking your car on a hot day in full sun for 8 hours.


Welcome to the forum and thanks for the information. I just got an update from WFAA that we broke a record this afternoon and hit 108.

So with these temps and with that amount of battery usage - are you using the fan or the cool option? And what is the temp inside your car before you precool it or get in?


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## iChris93 (Feb 3, 2017)

GDN said:


> Welcome to the forum and thanks for the information. I just got an update from WFAA that we broke a record this afternoon and hit 108.
> 
> So with these temps and with that amount of battery usage - are you using the fan or the cool option? And what is the temp inside your car before you precool it or get in?


Would using just the fan be effective at all when it's so hot outside?


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## GDN (Oct 30, 2017)

iChris93 said:


> Would using just the fan be effective at all when it's so hot outside?


I had to think about that at first as well. Some say yes and even 108 degree air outside is better than the 133 degree air inside, so likely yes.


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## iChris93 (Feb 3, 2017)

GDN said:


> I had to think about that at first as well. Some say yes and even 108 degree air outside is better than the 133 degree air inside, so likely yes.


That does make sense, but may not get it below the threshold so it would always be on.


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## jtk00l (May 15, 2018)

Currently there is no option to just use the fan. If using overheat protection you have no control over that. The car will do whatever it has to do to keep the car at 105 degrees. So on a very hot day it appears it must be using the a/c some to keep it at 105 inside the cabin. I just wanted to let others know because if you had a long commute it might be a problem with a 5 mile battery drain for 8 hours. I am going to test having it off tomorrow and compare as it is suppose to be just as hot here tomorrow. Now 108 degrees.


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## Impatient (Sep 19, 2017)

If the 3 is like the S, the cabin overheat feature won't engage if the battery is at less than 20% SOC, I believe. Has anyone verified that this is the case? (If this is in the Model 3 docs, forgive me for not remembering.)


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## GDN (Oct 30, 2017)

jtk00l said:


> Currently there is no option to just use the fan. If using overheat protection you have no control over that. The car will do whatever it has to do to keep the car at 105 degrees. So on a very hot day it appears it must be using the a/c some to keep it at 105 inside the cabin. I just wanted to let others know because if you had a long commute it might be a problem with a 5 mile battery drain for 8 hours. I am going to test having it off tomorrow and compare as it is suppose to be just as hot here tomorrow. Now 108 degrees.


So that appears to be the difference between those that picked up overheat from that early release with the hidden screen. Those that have it through a 24.X release have an option for fan only or cool ! They are making advancements.


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## PandaM3 (Apr 23, 2018)

So what’s the advantage of doing this? Does the cabins electronics get damaged due to heat? Why can’t I just turn the AC on a few minutes before I get in the car?


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## garsh (Apr 4, 2016)

PandaM3 said:


> So what's the advantage of doing this?


Interior materials can slowly be damaged over time by heat. We've also had one report of the glue holding the vanity mirror failing due to heat. Plus, if you have anything stored in the car, you may want to keep it cool.

But the main reason it was implemented is because of child and dog deaths due to people forgetting/leaving them in a hot car.


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## SoFlaModel3 (Apr 15, 2017)

iChris93 said:


> Would using just the fan be effective at all when it's so hot outside?


My car warms to 100-110F inside rather than the previous 125-135F, so it is definitely helping.


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## iChris93 (Feb 3, 2017)

SoFlaModel3 said:


> My car warms to 100-110F inside rather than the previous 125-135F, so it is definitely helping.


What's the outside temp then?


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## KarenRei (Jul 27, 2017)

jtk00l said:


> Since this feature was added I thought I would let you know what kind of drain this can put on the battery. Today it is 104 degrees here in Dallas Texas and parking in full sun I am getting an average battery drain of 4-5 miles per hour.


What's your vampire drain by comparison? It's not the raw power consumption figure that matters, but the excess consumption. It'd be nice to actually do a full 8-hour run and compare it to vampire drain on a day with similar weather without cabin overheat on.

Something about this figure seems horribly wrong, regardless. 4,5mi / 310mi * 75kWh = 1,1 kWh per hour = 1,1 kW. That's _way_ more power than a simple fan should use. Order of magnitude more.


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## SoFlaModel3 (Apr 15, 2017)

iChris93 said:


> What's the outside temp then?


High 80s-low 90s F -- parked in direct sun for 9-10 hours straight daily.


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## KarenRei (Jul 27, 2017)

garsh said:


> Interior materials can slowly be damaged over time by heat. We've also had one report of the glue holding the vanity mirror failing due to heat. Plus, if you have anything stored in the car, you may want to keep it cool.
> 
> But the main reason it was implemented is because of child and dog deaths due to people forgetting/leaving them in a hot car.


Including the young daughter of a friend of mine. The friend is currently on trial for manslaughter, despite it being an accident (he didn't realize she was still in the car; she was asleep in the back and hadn't gone to daycare because she was sick). Baked to death at temperatures around 65°C / 150°F.

It's not extremely common, but when it happens it's horrific. A horrific death to the child. A horrific experience for the family, followed by a lifetime of guilt. And potential jailtime (after years of pre-trial stress), even if it was an accident. It's not extremely common, but it's more common than you'd think; several dozen children die like this per year in the US. I imagine the figure for pets is 1-3 orders of magnitude higher.

All issues of upholstery longevity aside: How _sure_ are you you'll never make a mistake in your life?


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## Jayc (May 19, 2016)

For the past century or more, cars were left out in the sun and got overheated. Nothing new there so we have to put things into perspective:

What Tesla could do is to have a few options:

1. Give the option to pick either fan-only or full ac overheat protection

2. Fan-only but auto switch to ac if temperature exceeds a specified limit option

3. If someone is detected inside *and* cabin reaches extreme heat, automatically go to ac overheat protection mode irrespective of user-selection

4. No overheat protection, the feature is allowed to be switched off

It can be made as complicated as one would like. Or not!


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## KarenRei (Jul 27, 2017)

Jayc said:


> For the past century or more, cars were left out in the sun and got overheated.


And for the past century, people and pets have died in them, and their interiors have degraded. Not sure what the point is here.



> 1. Give the option to pick either fan-only or full ac overheat protection


You can do this. Cabin overheat protection is fan-only. If you want AC, just turn the AC on with the app.



> 3. If someone is detected inside *and* cabin reaches extreme heat, automatically go to ac overheat protection mode irrespective of user-selection


Nice idea, but it's not enough. My friend's daughter still would have died in her carseat. Just because a child is in a vehicle doesn't mean that it's easy to detect that the thing applying weight to the seat is a human.

Not that Tesla has interior cameras in the back anyway.


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## SoFlaModel3 (Apr 15, 2017)

Jayc said:


> For the past century or more, cars were left out in the sun and got overheated. Nothing new there so we have to put things into perspective:
> 
> What Tesla could do is to have a few options:
> 
> ...





KarenRei said:


> And for the past century, people and pets have died in them, and their interiors have degraded. Not sure what the point is here.
> 
> You can do this. Cabin overheat protection is fan-only. If you want AC, just turn the AC on with the app.
> 
> ...


To clarify, current Cabin Overheat Protection for Model 3 has 3 positions...

1) Off
2) Fan Only
3) A/C


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## Vladimír Michálek (Sep 24, 2017)

KarenRei said:


> Nice idea, but it's not enough. My friend's daughter still would have died in her carseat. Just because a child is in a vehicle doesn't mean that it's easy to detect that the thing applying weight to the seat is a human.
> Not that Tesla has interior cameras in the back anyway.


Microphone. You have microphones inside. Sound analysis is computationally extremely cheap. Baby crying detected in closed car should pop an alert in the app and trigger A/C to immediately cool down to room temperature. If not acknowledged in the app or not resolved after some time, the car should call the owner, then if not answered or the baby is continuously/repeatedly detected even after some time past the notification was acknowledged, call the emergency service and unlock the car when they arrive and confirm the VIN.

With this implemented, it might actually be viable to keep the baby in the car when it's asleep and use the mobile app as a baby monitor.


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## garsh (Apr 4, 2016)

Vladimír Michálek said:


> Baby crying detected in closed car should pop an alert in the app and trigger A/C to immediately cool down to room temperature.


Unfortunately, you're not guaranteed that a baby will wake up and start crying.

Also, having a false-positive end up in calling emergency services would be annoying.


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## Vladimír Michálek (Sep 24, 2017)

garsh said:


> Unfortunately, you're not guaranteed that a baby will wake up and start crying.


That's why it should be the second layer, on top of the first "don't allow the inside get too hot in the first place". The point is that the baby can die even in those 40C when tucked in the baby seat. So cry detection should avoid that.


garsh said:


> Also, having a false-positive end up in calling emergency services would be annoying.


 If the car can keep the temperature low enough, it doesn't have to call 911 for few hours. How long do you go not checking the phone. But why not have it as a last resort option.


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## garsh (Apr 4, 2016)

Vladimír Michálek said:


> How long do you go not checking the phone.


Which would also make false-positive notifications annoying.


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## Jayc (May 19, 2016)

Overheat protection is not going to solve all the problems in this world. Whatever solution is offered, its not going to completely prevent people being silly. I would not even dream of leaving any living being inside a car for more than a couple of minutes with windows shut if there is the slightest chance of the cabin heating up, just does not make sense under any circumstance. Winter would be the only exception but even then, the occupant has to be alert and in a position to get out if required. Basic common sense.

To me overheating protection is more of a convenience feature that helps to reduce cabin temperature (as much as possible, no guarantees) when parked out in the sun for prolonged periods.


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## KarenRei (Jul 27, 2017)

Jayc said:


> Overheat protection is not going to solve all the problems in this world. Whatever solution is offered, its not going to completely prevent people being silly. I would not even dream of leaving any living being inside a car for more than a couple of minutes with windows shut if there is the slightest chance of the cabin heating up


It wasn't exactly my friend's plan either. :Þ

Are you always, 100% sure, and ultimately correct, about the location of every living being in your life, and have never turned out to be wrong?

Willing to bet their lives on that?


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## jtk00l (May 15, 2018)

Wanted to give you guys an update on the overheat protection battery drain with really hot weather. Did some testing and got the following results. Temperature outside was 103 degrees outside each day this was tested. I tested for 4 hours each afternoon and am giving you the averages.

Overheat with A/C:
Kept car at 105 degrees
5 mile battery drain per hour average

Overheat with Fan only:
Kept car at 125-130 degrees
1 mile battery drain per hour average

No Overheat protection on:
Car was 151 degrees
0 mile battery drain

Something to keep in mind if you have a long commute or have your car parked at the airport while going on a week trip. You might come home to a car with little to no battery. I believe it cuts off with 20% battery left.


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## pdeinselen (Apr 18, 2018)

Thanks for posting. I forgot I was going to share my results as well. I wrote up a quick read Medium article.


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## pdeinselen (Apr 18, 2018)

jtk00l said:


> Something to keep in mind if you have a long commute or have your car parked at the airport while going on a week trip. You might come home to a car with little to no battery. I believe it cuts off with 20% battery left.


Like you said it cuts off at 20%. Also Cabin overheat only runs for 12 hours after exiting the vehicle. The only concern I would have is battery cooling and that is a small percentage per day.


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## garsh (Apr 4, 2016)

pdeinselen said:


> Thanks for posting. I forgot I was going to share my results as well. I wrote up a quick read Mediuam article.


Thanks!


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## ahagge (May 6, 2017)

Alas, I don't have the feature yet (stuck on 2018.21.9). Has anyone confirmed what happens if Cabin Overheat Protection (in A/C mode) is activated, but the windows are left at least partway down?


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## babula (Aug 26, 2018)

Not sure if this has been mentioned but I'm wondering which version introduced this feature. I'm on 34.1 and don't see this option in the settungs.

Also curious if anyone has an answer to the question mentioned above.


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## SoFlaModel3 (Apr 15, 2017)

babula said:


> Not sure if this has been mentioned but I'm wondering which version introduced this feature. I'm on 34.1 and don't see this option in the settungs.
> 
> Also curious if anyone has an answer to the question mentioned above.


I don't have my car in front of me right now, but try going to the Safety tab and then click the settings cog in the top right. IIRC it's in that menu.


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## babula (Aug 26, 2018)

SoFlaModel3 said:


> I don't have my car in front of me right now, but try going to the Safety tab and then click the settings cog in the top right. IIRC it's in that menu.


Yup that was it, thanks man.


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