I think I'm going to turn OFF cabin overheat protection

[nvx1977]

Very informative post. Thank you very much!

Is there an active system within a model 3 that monitors battery environment or keeps batteries cool on hot days? Is that necessary or an issue?

I don't think it's an issue. In the US, in hot climes, ambient temps max out around 40C / 100F on a typical summer day. Radiative heat from a black-top road might add a bit more heat, so we're talking about parking outside in direct sun. These are not temps that would cause concern from a safety perspective. There may be a slight hit to overall battery longevity if you're in the habit of keeping the battery near fully charged (lithium batteries don't like heat + high charge at the same time). But Tesla is really good at managing battery temps to minimize this type of degradation. Best in class. I don't yet trust other manufacturers to have this figured out as well as Tesla, frankly.

Here's something you might find interesting. This is part of the diagnostics UI that owners don't have direct access to. This was on my Model S during a mobile technician visit. This particular screen shows battery temps in module blocks as well as the individual in-series voltages. This was a hot day, mid 90s (35C), but the battery itself was lower (30C).

 

[MP3Mike]

Absolutely. The BMS is always active and will heat or cool your battery as necessary. It is necessary in both hot/cold extremes.

I don't think that is true. It will not heat, or cool, the pack while it is parked unless you start a preconditioning cycle or you are charging.

 

[insaneoctane]

I don't think that is true. It will not heat, or cool, the pack while it is parked unless you start a preconditioning cycle or you are charging.

I can't personally speak to the cold since I'm in So Cal, but I can attest to my vehicle running the cooling pumps for the battery without any intervention from me.

 

[MaryAnning3]

There may be a slight hit to overall battery longevity if you're in the habit of keeping the battery near fully charged (lithium batteries don't like heat + high charge at the same time). But Tesla is really good at managing battery temps

Thanks a lot for the really helpful post on this!! So if I park in near Santa Barbara in the summer in direct sunlight and leave the car for a week or two I should be okay as long as I keep the charge around 70% to 40%? Does that seem like an okay strategy? Do you think it is worth it to buy a $300 car cover made for the model 3 instead of the $40 one I have now?

 

[MaryAnning3]

Here's something you might find interesting.

Very cool! I guess T1 and T2 are each battery temperatures? Are those 3.99...v cell voltages or something?
Are there like numerous temperature sensors in the battery?

 

[eloder]

Try leaving your phone or iPad in hot car...it turns off.

The Tesla's computer won't be damaged by summer interior temperatures for the very same reasons that your iPhone or iPad loses 20%+ of its battery capacity within a year of use: car components are designed to handle a ton more stress and last longer than an iPhone or iPad.

 

[nvx1977]

the problem with phone and ipad is that those processors don't really have a good heat sink and fan system to keep things cool, so when you leave them in a hot car, the processor (which is still running) get hotter than its safe operating temps and the phone shuts down to protect the chip from getting fried or the battery from getting too hot (risk of fire).

In the car, the computer, which is buried, is protected by shade and will also have heat sinks and some sort of cooling system (either air or liquid). And those processors are mostly off when the car is parked. Given that most modern processors can handle temps near 200F, there's no way a hot cabin could come close to damaging the car's computer.

It makes no sense to compare mobile devices in hot cabin with the car's electronics. We've had controlling computers in cars for many decades now. There are no widespread issues of heat damaging circuitry.

 

[kdono]

Obviously there will be people who flame me because they don't care about a few lost miles...whatever.
I'm seeing enough mileage loss that I'm thinking keeping my car at a comfy 105 F is not worth it. I'm already running NO-AC mode for cabin overheat protection and I lost 13.5 miles (~3.3 kWh) in 5.3 hours today. It was only 86 F outside. The car was parked & off for all these data points. I don't have small children.
View attachment 329975

Good day all. A new owner, one month, who drives 200 miles per day.

Looking for input on keeping the interior cool enough so as not to damage the electronics. Have a front windshield reflective cover which installs on the inside and have the mesh screens installed along the insides of the roof. Car parked outside all day and the inside temp quickly rises to over 100. Anyone aware of reflective covers for roof? Or, perhaps some comments about best practices for keeping the interior cool enough not to damage the electronics?

Many thanks.

Ken

 

[mswlogo]

Good day all. A new owner, one month, who drives 200 miles per day.

Looking for input on keeping the interior cool enough so as not to damage the electronics. Have a front windshield reflective cover which installs on the inside and have the mesh screens installed along the insides of the roof. Car parked outside all day and the inside temp quickly rises to over 100. Anyone aware of reflective covers for roof? Or, perhaps some comments about best practices for keeping the interior cool enough not to damage the electronics?

Many thanks.

Ken

A little over a 100 is nothing for a car interior. Anything under a 120F is fine.

BTW I have the Tesla sunroof and rear sunscreens as well. But someone mentioned a good point. They don’t prevent heat from entering the cabin though, they don’t reflect anything back. I got them more for sound deadening than cooling. I know some folks put thinsulate above the sunroof screen.

Be careful trapping heat against the fragile glass that likes to crack.

Possibly something on side windows would be your next best spot to focus on if your that concerned.

 

[TMThree]

I'm seeing enough mileage loss that I'm thinking keeping my car at a comfy 105 F is not worth it. I'm already running NO-AC mode for cabin overheat protection and I lost 13.5 miles (~3.3 kWh) in 5.3 hours today. It was only 86 F outside. The car was parked & off for all these data points. I don't have small children.
View attachment 329975

It's not about children. The cabin protection option was put in place when Model S/X screens started to sustain damage from head buildup in the interior. Proceed at your own risk.

 

[kdono]

Thanks. Interesting about the glass being fragile... I come from the aviation world where using sunscreens is fairly common with glass.

I think I read somewhere that the interior temp is more of a concern for the electronics of the screen, which is why I’m concerned.

Ken

 

[jerry33]

Good day all. A new owner, one month, who drives 200 miles per day.

Looking for input on keeping the interior cool enough so as not to damage the electronics. Have a front windshield reflective cover which installs on the inside and have the mesh screens installed along the insides of the roof. Car parked outside all day and the inside temp quickly rises to over 100. Anyone aware of reflective covers for roof? Or, perhaps some comments about best practices for keeping the interior cool enough not to damage the electronics?

Many thanks.

Ken

What I do is put cabin heat protection on, open the pano roof to 15% (more is counter productive and vent isn't open enough), and crack the other windows. This keeps the temperature relatively cool and uses minimal electricity.

 

[jerry33]

Thanks. Interesting about the glass being fragile... I come from the aviation world where using sunscreens is fairly common with glass.

I think I read somewhere that the interior temp is more of a concern for the electronics of the screen, which is why I’m concerned.

Ken

I don't really buy the fragility of the glass. The roof is made in the same way the windshield is made--with a layer of plastic between two layers of glass. Over six years now 124K miles, no glass damage--even from hail.

 

[jgmartin]

The energy use here is far, far more than what I experience using the cabin overheat protection (with ac) in Florida. I assume maybe you’re including the beginning of a drive in the morning, where consumption seems to always be significantly higher than normal for the first few miles?

 

[Triplett]

Kids and animals are still dying these days due to accidents & neglect, this feature is to make sure there are no such accidents. If you have no kids or animals, then turn off the feature and the car will be fine. Your car auto regulates the battery's temperature already.

Worth noting cabin overheat protection only works for 12 hours after you leave your car. So the feature is designed for safety reasons, not some interior-saving reasons.

For saving electronics you are waiting for camper mode, which is coming that'll allow you to keep a steady flow of air & temperature for 48 hours after parked.

This feature has ABSOLUTELY NOTHING to do with kids and animals and accidents. ZERO!

It is designed to prevent damage to sensitive electronics caused by prolonged, excessive heat exposure.

You have confused this feature with dog mode.

To all the users who liked your post or rated it informative.....smh....

 

[diamond.g]

This feature has ABSOLUTELY NOTHING to do with kids and animals and accidents. ZERO!

It is designed to prevent damage to sensitive electronics caused by prolonged, excessive heat exposure.

You have confused this feature with dog mode.

To all the users who liked your post or rated it informative.....smh....

Which is weird cause this feature didn’t even exist before the last year or so, and why would they let us turn it off if it is needed to keep the electronics cool?

 

[Glamisduner]

I leave mine on, but have it set not to use the AC. In the summer I will run the sun shade and crack the windows. I also cannot pre-cool because we have no phone reception at work, and the car cannot connect to the wifi network for some reason, but I do it because the couple percent of battery does not really matter that much for my daily commute.

 

[follow.johnny]

Living in Socal and temperatures are slowly getting back into 80-90s. I currently have Cabin Overheat Protection on (without AC) if temperatures are below 90. My rule of thumb is if temperature is 90+, I will enable with AC on.

 

[Triplett]

Which is weird cause this feature didn’t even exist before the last year or so, and why would they let us turn it off if it is needed to keep the electronics cool?

Because it took them time to collect enough data to determine how much it would cost them in warranty claims.

Took them the same amount of time to collect enough data to determine they could boost performance by 5 percent in an update without incurring a fortune in warranty costs.

 

[animorph]

It absolutely was introduced as a safety measure for kids and pets. The safety of the electronics seems like more of a myth. I don't remember any Tesla announcement about it. Links for that?

Here's the article with the release notes for Cabin Overheat Protection:

Tesla v8.0 software update is being pushed right now, all the details and full release notes - Electrek


"
Cabin Overheat Protection
In an industry-first safety measure, we’re also introducing Cabin Overheat Protect, focused on child (and pet) safety. This feature keeps the car at a safe temperature for hours, even when the car is off. This feature is only made possible by an electric vehicle with Tesla’s uniquely large battery packs."