# Hot Garage Questions



## BI_EV_Solar_Advocate (Mar 19, 2021)

I have a garage that gets hot in the summer. It is not unusual for it to get to 98F even with my garage windows open.

Will that temperature damage my battery or enhance its degradation?

Can my MY be set to keep the interior below a set temperature while parked and plugged in?


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## FRC (Aug 4, 2018)

First, proofread your thread title. I don't think that discussion of a whore garage is appropriate here.   Second, I don't believe that garage temps in that range will be an issue. If you are overly concerned you can use cabin overheat protection to keep the interior temp lower; not sure how much that would lower your battery temp.


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## Bigriver (Jan 26, 2018)

BI_EV_Solar_Advocate said:


> Can my MY be set to keep the interior below a set temperature while parked and plugged in?


Yes, cabin overheat protection will keep the interior of the car no higher than 105 F. It is an option in the Safety & Security menu.

I actually never use that, though. My car is not often in a prolonged heated situation. I will be curious to see other responses of people who do and why.


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## lance.bailey (Apr 1, 2019)

being in the pacific NW rainforest, I only get a week or two max when the garage heats up to objectionable temperatures. And every summer I consider a wall fan arrangement to kick in at a certain temperature. Fortunately the temperature goes down again before I get moving.

here is the unit i would use to turn the fan off and on, a ductstat DS100:










and here is the sort of in wall I would use (suncourt brand).










or this (cyclone brand)


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## RonAz (Oct 16, 2018)

I leave My 2018 Model 3 in an unheated and uncooled garage in the Scottsdale, Az area for three to four months in the summer. Plugged in at 50% without climate control on. Except for the dust on the outside, I have not noticed any effects from it. Inside at 110 degrees is much cooler than 80 degrees in the sun outside. I have never seen above 98 degrees when I have checked on it while gone.


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## GDN (Oct 30, 2017)

Welcome to the forum. As others noted Cabin Over Heat Protection can keep the car at 105 and not let it get hotter, but you won't need that in the garage at home, as you noted it is lower than the 105 in the garage. The COHP uses battery and AC anyway. I do use that when parked outside on a sunny day and it makes a huge difference and is very nice, but not at home. 

The car is very very smart and the battery will protect itself in extreme hot or cold. Regardless of what setting you choose, if the HV - High Voltage (drive battery) has charge the car will heat or cool the battery if temps get extreme enough, without you doing anything.

The best and likely only thing you need to do is keep the battery charged and keep the car plugged in when home. Many don't plug in every day, you'll find what fits your needs best, but the manual and Tesla say a plugged in Tesla is a happy Tesla.

Based on your driving habits set your charge level to 50% to 90% depending on what you need on a daily basis. 90% may be high per some opinions, but Elon has said that is OK. You do not want to charge higher than 90% on a daily basis and you never want to charge to 100% and let it sit at that level very long. If you need 100% to leave on a trip, try to time that to within an hour or so of when you are leaving the house.


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## BI_EV_Solar_Advocate (Mar 19, 2021)

@lance.bailey
Ventilating garage is a good idea.
My outdoor temp drops to 68-70F at nite.

I thought about using a digital differential thermostat:
http://www.sbesolartech.com/picdifftherms.html


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## JasonF (Oct 26, 2018)

BI_EV_Solar_Advocate said:


> I have a garage that gets hot in the summer. It is not unusual for it to get to 98F even with my garage windows open.
> 
> Will that temperature damage my battery or enhance its degradation?
> 
> Can my MY be set to keep the interior below a set temperature while parked and plugged in?


Your garage only gets up to 98F? I'm in Florida, my garage can easily get over 100 in late spring/summer.

It shouldn't make much difference to the battery considering that a lot of people park outside, especially at work, for hours on end.


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## Ed Woodrick (May 26, 2018)

Don't worry about it. It isn't going to bother the battery.


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## MnLakeBum (Mar 17, 2021)

Hot climates and fast charging are not ideal and will certainly accelerate battery degradation.

https://cleantechnica.com/2019/12/1...more-battery-degradation-than-age-or-mileage/


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## garsh (Apr 4, 2016)

BI_EV_Solar_Advocate said:


> I have a garage that gets hot in the summer. It is not unusual for it to get to 98F even with my garage windows open.
> 
> Will that temperature damage my battery or enhance its degradation?


I think you'll be fine.

I can't find a reference right now, but I believe the optimal operating temperature for Tesla's batteries is around 80° F.

This article talks about the battery cooling system kicking in during supercharging at about 113º F. So it's probably not worth worrying about until you're up into those temperatures.


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## TomT (Apr 1, 2019)

Leave it plugged in and it will cool the battery if necessary.


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## JasonF (Oct 26, 2018)

MnLakeBum said:


> Hot climates and fast charging are not ideal and will certainly accelerate battery degradation.
> 
> https://cleantechnica.com/2019/12/1...more-battery-degradation-than-age-or-mileage/


Not a lot can be done about that aside from moving to a cooler climate, or not buying an EV if you live someplace where it gets hot. Even if you read that article and build an arctic air conditioned garage, you still have to park outside in summer occasionally.


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## MnLakeBum (Mar 17, 2021)

JasonF said:


> Not a lot can be done about that aside from moving to a cooler climate, or not buying an EV if you live someplace where it gets hot. Even if you read that article and build an arctic air conditioned garage, you still have to park outside in summer occasionally.


Agreed. I didn't really understand how hard hot climates were on regular lead acid batteries until I move to Sacramento. I was lucky to get 3 years out of car battery there and had a few fail in less than two years. EV batteries are improving but heat is still an enemy.


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## Ed Woodrick (May 26, 2018)

MnLakeBum said:


> Hot climates and fast charging are not ideal and will certainly accelerate battery degradation.
> 
> https://cleantechnica.com/2019/12/1...more-battery-degradation-than-age-or-mileage/


There is so much about this article that make me suspect it. 

A graph that gives data over 17 years (210 months) for electric cars. 
The graphs of some individual cars don't seem to reflect their overall graph
Their overall graph is completely linear, that's definitely not going to reflect reality
They don't look at different generations of batteries. Battery technology has changed a lot, they can not be compared
Other studies have indicated other outcomes, especially when it comes to fast charging.
6300 cars over 21 models and a number of vehicle years doesn't tend to create statistical accuracy. 
There are numerous examples of battery generations having significant differential on the numbers. Nissan had a problem with early Leafs in Arizona having premature failure, that got fixed and isn't a significant issue anymore. Tesla had some battery changes along the same time, decreasing the number of battery issues.


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## JasonF (Oct 26, 2018)

MnLakeBum said:


> Hot climates and fast charging are not ideal and will certainly accelerate battery degradation.







Sorry. Had to be done.


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## Feathermerchant (Sep 17, 2018)

If your car is in a closed garage and the A/C or anything else comes on, what happens to the temperature of the garage?
It goes up. It has to. You've added energy to the garage. Even a fan has that effect. The only thing to do if you want to cool the car is cool the garage. Easy to do if the outside temp is less than the inside temp. As mentioned before, a fan will do the job. If it is hotter outside though you'll need an air conditioner for the garage. 

To keep the garage cooler, consider adding insulation to the ceiling or walls and insulate the garage door. This works really well if it is an attached garage because the air conditioned house will also help cool the garage. I live in a pretty hot place and I can say that the garage is much cooler in the summer since we switched to EVs. It is also cooler in the winter.


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## MnLakeBum (Mar 17, 2021)

Ed Woodrick said:


> There is so much about this article that make me suspect it.
> 
> A graph that gives data over 17 years (210 months) for electric cars.
> The graphs of some individual cars don't seem to reflect their overall graph
> ...


We have a lot to learn about EV battery health and certainly the batteries have and will continue to improve. From what we know now, it's pretty clear than more extreme temperature climates are harder on batteries than moderate climates. My Tesla spent the first 3 years of it's life in Sacramento where they average about 67 days each year over 90*. It was often stuck in traffic on those days or parked outside in the heat. All the research I've done points to that heat being a contributing factor to battery degradation and certainly a possible reason why my battery is now being replaced under warranty after only 6 years of use.


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## Ed Woodrick (May 26, 2018)

MnLakeBum said:


> We have a lot to learn about EV battery health and certainly the batteries have and will continue to improve. From what we know now, it's pretty clear than more extreme temperature climates are harder on batteries than moderate climates. My Tesla spent the first 3 years of it's life in Sacramento where they average about 67 days each year over 90*. It was often stuck in traffic on those days or parked outside in the heat. All the research I've done points to that heat being a contributing factor to battery degradation and certainly a possible reason why my battery is now being replaced under warranty after only 6 years of use.


Yea, and like I said, some of the early batteries showed that tendency, but newer ones are significantly better. And as I explicitly mentioned, Nissan found the issue mentioned in the article above and fixed it.

Does the article separate all the batteries before and after? NO!

Batteries that are less than 5-6 years old are showing a significantly different profile for hot ambient temperature usage than ones that are older.

While there are a few newer batteries that are needing replacement, they are few and far between when compared to the older batteries.


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