Cabin Temperature Protection - What's it REALLY for

[SDBob]

All Tesla vehicles have a feature called "Cabin Temperature Protection". This feature keeps the cabin temperature below 105 F. It's specific purpose has been postulated to be for human or animal life preservation, some say for electronic or LCD screen preservation, but I have a different view.

Elon wouldn't design a system to keep your toddler safe for 12 hours at 105 F. It's clearly not for occupant safety.

After exhaustive research into degradation behaviors of a LiPo battery with respect to contributing factors, one fact remained clear. Sustained temperatures over 40C are a tipping point at, over which, degradation falls off a cliff. (Of note is this degradation is amplified with SOC. Meaning the absolute worst hellish condition you can impose on your battery is a 100% SOC at over 40C.) A common value that appears in whitepaper after whitepaper is 40 C. 40 C equals roughly 104 F.

I firmly believe this feature is included to give educated owners the option to provide an environment for their battery that minimizes degradation over time.

I also firmly believe this feature isn't advertised or discussed by Tesla as such would result in media criticisms such as "Tesla batteries degrade if not kept under..." You get my point.

I welcome your input on this hypothesis, and encourage all Tesla owners interested in prolonging their battery lives to consider the use of this feature.

Love and best to all.

 

[luckyj]

The battery has it's own internal cooling system. Which, as far as I know, will kick in whenever it thinks it needs to. So why would they cool the cabin to protect the battery? While it does sound like it might help, it seems marginal at best.

 

[SDBob]

The battery has it's own internal cooling system. Which, as far as I know, will kick in whenever it thinks it needs to. So why would they cool the cabin to protect the battery? While it does sound like it might help, it seems marginal at best.

Interesting. Does the internal cooling system for the battery operate while the vehicle is asleep?

 

[SDBob]

New Tesla software to prevent hot car deaths

Dozens of kids die each year in hot cars. A new Tesla software feature could help prevent a few of those.

money.cnn.com

Well damn. Maybe it actually is for occupant protection. If so it would be their worst designed feature. A motion activated system bringing temps to the 80F range and sending persistent push notifications through the app would seem like a MUCH better option. Imagine leaving your toddler at 105F for 12 hours.

 

[luckyj]

Interesting. Does the internal cooling system for the battery operate while the vehicle is asleep?

I don't know the details, but there are folks lurking here who have much better knowledge of the Battery Management System (BMS). From what I understand, the BMS monitors the battery's conditions fairly regularly. And has all sorts of factors that play into when each cooling (or heating) mechanism will kick in. I don't think Tesla heats the cabin in the winter to heat the battery Just pump heat straight into it via coolant system.

 

[IronCoffee_Max]

I think its more like protection for the seats and plastic and stuff you may have inside.

 

[BobDolesGhost]

I've heard its for LCD protection as well - but if that were the case, you'd think Tesla would just remove this as a setting and always leave it on

I very much like your idea of using the cabin camera to detect motion in the car and to bring the temp down (or up) to something survivable and to annoy the crap out of you with notifications. This would obviously be disabled when dog/camp mode was on

I leave it on so that my car isn't a hell'ish oven whenever I get in it on a sunny summer day. It cools down much quicker from 101 degrees than 140. I rarely remember to turn the AC on in the app before its time to go - and my time to go varies day to day and scheduled departure seems like a hit or miss waste. Leaving overheat protection on wastes probably 5 to 8% of my battery sitting in the lot at work, but I only need 40% battery for my daily commute.

 

[Silicon Desert]

Leaving overheat protection on wastes probably 5 to 8% of my battery sitting in the lot at work, but I only need 40% battery for my daily commute.

AND as you may have considered, a bunch more wear and tear on your AC system running a lot each day while idle.... if you are ok with that.
I rather use a car cover.

 

[SDBob]

Ok... so the LCD screen, adhesives, fabrics, plastics, electronics... pretty much any material other than metal will live much longer at 105 F than 140+ F, which is what my internal temps reach very quickly in the So Cal sun.

I still tend to reject the notion that it's for life safety. 105 F with no breeze for 12 hours with no water is survivable, but marginally.

Maybe it's time to push for a motion activated cabin detection system for life safety. Be it dogs, cats, or god forbid your child.

Appreciate the input. Together we are genius...

 

[SDBob]

AND as you may have considered, a bunch more wear and tear on your AC system running a lot each day while idle.... if you are ok with that.
I rather use a car cover.

It's hard to quantify "wear and tear" on a heat pump system. We have the compressor motor's sealed ball bearings, and a few fan motor bearings?
Car covers are only for smart people that aren't lazy. lol

 

[joelliot]

It may be a strange concept for some, but my car will often sit for a couple days without moving. If it was really for system protection, either battery or interior electronics, I would hope I had the option to run it anytime the car is plugged in instead of stopping after 12 hours.

 

[angus[Y]oung]

Elon wouldn't design a system to keep your toddler safe for 12 hours at 105 F. It's clearly not for occupant safety.

Imagine leaving your toddler at 105F for 12 hours.

105 F with no breeze for 12 hours with no water is survivable, but marginally.

@SDBob I hope you're not leaving your toddler unattended in the car for 12 hours, in any temperature!

I do like your idea of a motion-activated system that would keep the temperature at a more human-friendly level. It wouldn't help for someone's napping toddler, but I guess it would kick in when they wake up and start fussing (depending how sensitive the detection is).

 

[SDBob]

It may be a strange concept for some, but my car will often sit for a couple days without moving. If it was really for system protection, either battery or interior electronics, I would hope I had the option to run it anytime the car is plugged in instead of stopping after 12 hours.

I think that's a very common scenario. So although it makes less sense than a peso (Grandpa's saying), maybe it is in fact for life preservation. VERY very poorly designed if that's the case in my opinion. Which would be the 1st poorly designed feature on my car so far. Not 100% convinced. It can't be difficult to implement a motion feature when they're supposedly tracking eyeballs, lol.

 

[KArnold]

I don't think the system maintains the cabin temp @ exactly 105 degrees. I'd guess that's when it triggers going down to your preset temp. If so, that might save a dog.

 

[GtiMart]

The system will trigger when temperature goes higher than 105F and work a bit to get it down. When the car sleeps, it might not wake up exactly at 105, it might get a few degrees higher. It will not bring the car down to your set temp, it just wants to get it a bit under 105. AFAIK

 

[KArnold]

I actually use Dashboard for Tesla which is a little bit smarter. You choose your plus or minus internal temperature - in my case, 75-degrees plus or minus 20 degrees (although, I don't use it to HEAT the cabin - I'll schedule a charge completion time for that, including enabling HEAT).. If that limit is reached, the AC/Heat will engage to bring it to your pre-set temperature. You can also choose things like interval, hours, keep HEAT/AC on, min battery SOC settings, etc.

 

[Candleflame]

The battery has it's own internal cooling system. Which, as far as I know, will kick in whenever it thinks it needs to. So why would they cool the cabin to protect the battery? While it does sound like it might help, it seems marginal at best.

it doesnt, tesla doesnt cool their batteries (even while driving) unless at high temperatures. I think its somewhere around 45-55C cant remember. Maybe 45C for driving, 55C for DC fast charging.

If by some fluke the battery goes above 45C while standing I do think the car would wake up and cool the battery but this just doesnt happen. I used to have the car in Mount Isa where mid 40s temps are normal in summer and it didnt run the coolant pumps there either. I guess its difficult for the battery to go above air temperature.