Energy Used to Keep EV Battery Warm - Data

[UncleDave]

When people talk about the cost of keeping the EV ready to go being expensive, the question that really needs to be asked is - compared to what?

You can do nothing with either type at -17F
The EV will ALWAYS at least run if not in turtle mode for a while. It will get you to work.
The Ice may not start. Happens ALL the time.

You can plug the EV in for between 86C and 5 dollars a night (california) and start full every morning and jump into a warm car ready to go. You can do this in a garage, or in the driveway.
Bonus in winter -heating an EV in the garage raises the garage temp a bit.

Diesel heaters vary from about 750 watts to 1500 -so on par or more than the Lyric// EV
It's not really an option with a diesel to not heat it some way at -17.

You can idle the ice in the driveway consuming some fuel and also reducing your range in cali its around 4-5 a gallon. My v6 uses about a half gallon an hour and to get it really warm from -17 and clear the windows it needs about 20 min to half an hour. so a bit less money. Im also fouling the oil at an accelerated rate doing that and shortening my OCI so other costs to consider. It gets notably less mileage in cold weather as well - between the warm up cost and the lower mileage cost Im using at least as much money wise as the EV - and having to visit a remote location to keep the car fed vs just come home and park stinks.
No one can sell me that going to the gas station at 17 below is convenient or fun.

You can heat the garage to keep the ice warm - if you use electricity it will cost more than the EV,

Or run a kerosene heater in the garage - I get about a gallon for 15 hours, and k1 is about 10 a gallon. Id usually start it around 9-10PM before going to bed and kill it around 530-6 AM so get about 2 nights out of a gallon - back to 5 bucks a night. If you can find it at a pump you can run red kerosene for about half of what K1 cost but then you get to smell it. I have a source about a half hour away and I have 4 5-ers for kero.

 

[zyxelenator]

Mine was sitting for couple summers under direct scorching TX sun on the drive way, so it did cool itself a lot. And yeah it does add up some $. But cooling our van that would reach 135f+ in cabin was a very lengthy task( although it has 2 ACs, they seem to be rather week vs US brand cars). Bolt would cool itself so much faster, when remote started. We recently moved to another house and now have huge live oaks there and driveway is shaded all the time. Now it is Sienna`s turn to live outside. (For some reason TX homes have tiny garages, fitting two cars is almost impossible, we can in case of weather emergency, but that is within inches before hitting something. Never understood that, especially since folks love huge trucks here). P.S. both cars are fully tinted with ceramic, including windshields, and I used external reflective cover(serves as snow cover too) on top of it.

 

[dogememe]

Mine was sitting for couple summers under direct scorching TX sun on the drive way, so it did cool itself a lot. And yeah it does add up some $. But cooling our van that would reach 135f+ in cabin was a very lengthy task( although it has 2 ACs, they seem to be rather week vs US brand cars). Bolt would cool itself so much faster, when remote started. We recently moved to another house and now have huge live oaks there and driveway is shaded all the time. Now it is Sienna`s turn to live outside. (For some reason TX homes have tiny garages, fitting two cars is almost impossible, we can in case of weather emergency, but that is within inches before hitting something. Never understood that, especially since folks love huge trucks here). P.S. both cars are fully tinted with ceramic, including windshields, and I used external reflective cover(serves as snow cover too) on top of it.

Bolt HVAC is truly amazing. My 2017 got ice cold in moments and hot in an instant too. But that resistive heater sure sucked down the range! IDK about the new Bolt, I do plan to go test drive one ASAP because I'm curious, but based on my experience with the Prologue and Equinox EV, the HVAC system on Ultium vehicles is slooooow to heat or cool. It does work fine, it's not broken, it's just not INSTANT like the Bolt was. Then again those are larger vehicles with more interior volume and to GM's credit the heat pump system impacts the range FAR less. My Tesla has heating and cooling as good as the Bolt did so clearly heat pumps can work fine... I suspect GM is just trying too hard to be efficient to maximize range? Not sure. But a "blast it and screw efficiency" mode would be nice.

 

[jghall00]

Bolt HVAC is truly amazing. My 2017 got ice cold in moments and hot in an instant too. But that resistive heater sure sucked down the range! IDK about the new Bolt, I do plan to go test drive one ASAP because I'm curious, but based on my experience with the Prologue and Equinox EV, the HVAC system on Ultium vehicles is slooooow to heat or cool. It does work fine, it's not broken, it's just not INSTANT like the Bolt was. Then again those are larger vehicles with more interior volume and to GM's credit the heat pump system impacts the range FAR less.

On cold days, I wake up, grab the key to start the vehicle, then get ready for work. By the time I get in the vehicle, it's warm. I would use scheduled charging to do it, but my free nights plan ends at 5AM and I don't leave until 6 AM. The resistive heater in our other cars worked better as well, but the range impact was substantial. I'm fine with the heat pump since I can start the vehicle from anywhere using the key fob or app.

 

[y_p_w]

UncleDave covered it pretty well. The batteries will drive the car just fine when fully cold-soaked. -10F, -20F, etc. The big issue is DC Fast charging. The batteries need to generally get in the 70F range to charge at max speed.

In this case, GM (and I’m sure most all EV manufacturers) recommend keeping your car connected to your home charger when the ambient temps are below 32F or above 90F, so the battery conditioning system can keep the battery in this range and “maximize high voltage battery life”, per GM. I was just curious how much energy I was using when doing this on a really cold night.

I just looked up Tesla Model Y and they also state (in bold, large font, and in all capital letters). “The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.”

It was a series of cascading issues with the Chicago area. But lack of preconditioning does affect charge speeds, which then affects how available the chargers are. Tesla now has fees if Superchargers are crowded. I think 50 cents per minute if charged past 80% or stopped at the set limit. Maybe a 5 minute grace period? But the incentive is to get users out for more utilization where the charge rates are fastest.

And navigating to fast chargers should be done. I’ve just randomly driven to a Tesla Supercharger when driving my dad. He hates hearing navigation directions. But it spent something like 10 minutes doing the preconditioniting, while charge rates were limited to maybe 25-30 kW before it started increasing the charge rates. And that was in relatively warm weather.

 

[Patman]

I just looked up Tesla Model Y and they also state (in bold, large font, and in all capital letters). “The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it.”

I thought that if you weren’t going to be using an EV for an extended period of time it’s better to leave it at a lower SOC such as 50%? I’ve heard if it’s stored with the SOC at 80-100% that it’s not good for the batteries

 

[Brons2]

Mine was sitting for couple summers under direct scorching TX sun on the drive way, so it did cool itself a lot. And yeah it does add up some $. But cooling our van that would reach 135f+ in cabin was a very lengthy task( although it has 2 ACs, they seem to be rather week vs US brand cars). Bolt would cool itself so much faster, when remote started. We recently moved to another house and now have huge live oaks there and driveway is shaded all the time. Now it is Sienna`s turn to live outside. (For some reason TX homes have tiny garages, fitting two cars is almost impossible, we can in case of weather emergency, but that is within inches before hitting something. Never understood that, especially since folks love huge trucks here). P.S. both cars are fully tinted with ceramic, including windshields, and I used external reflective cover(serves as snow cover too) on top of it.

I think this is new houses everywhere, not just Texas. Garages just aren't what they used to be.

My Lightning does not fit in my garage despite only having a 5.5' bed.

 

[Brons2]

I thought that if you weren’t going to be using an EV for an extended period of time it’s better to leave it at a lower SOC such as 50%? I’ve heard if it’s stored with the SOC at 80-100% that it’s not good for the batteries

You can set desired state of charge in the app and still leave it plugged in to maintain optimal battery temperature. That's what I did when we spent 17 days out of the country in November. Probably was unnecessary as the weather was mild while we were gone, but I did so in case we got an early cold snap.

 

[JeffKeryk]

I thought that if you weren’t going to be using an EV for an extended period of time it’s better to leave it at a lower SOC such as 50%? I’ve heard if it’s stored with the SOC at 80-100% that it’s not good for the batteries

I charge to 75% to 80% unless I am going further. Charging settings such as complete time, level and limit are all configurable on your app.

 

[Arc]

I was paused by this for a minute also. Would an object shed heat faster (thus requiring more power to maintain warmth) if the wind is blowing?

If the object is my head it sheds heat pretty fast when the wind is blowing. Not much insulation up there.

 

[Torrid]

Begs the question, why are you bothering to heat the battery when the car isn't being used? It's not necessary.

 

[Torrid]

That's interesting, and not exactly inexpensive. Over the winter months that could add up to negative savings.

The thing is there's no reason to heat the battery when the car is just sitting. I never do and it sits in a parking lot for 2-3 days while I'm out of town working.

 

[E365]

Begs the question, why are you bothering to heat the battery when the car isn't being used? It's not necessary.

No, it’s not necessary, but it’s better for the long-term life of the battery. I generally don’t leave it plugged in either unless we’re approaching 0F. In this case I also wanted to see how much energy it used.

The owner’s manual of pretty much every EV says to leave it plugged in either always, or when in extreme hot or cold.

Tesla says leave it plugged in always (in large bold
letters). And totally avoid -22F or colder except for short periods.

Polestar says leave it plugged in always, especially in extreme hot or cold.

Lucid says leave it plugged in always, especially outside of -4F and 113F

GM says leave it plugged in when outside 32F or 90F

Ford says to leave plugged in below freezing

Porsche says to leave it plugged in above 86F

It’s going to be nearly -40F here in northern Minnesota later this week.

For me it’s a balance between keeping the battery warm overnight and also getting better range when I depart in the morning, or don’t leave it plugged in and have less range and then have to DCFC sooner and longer. With DCFC prices, keeping it warm overnight on cheap off-peak rates at home is probably cheaper than extra DCFC usage.

 

[Torrid]

No, it’s not necessary, but it’s better for the long-term life of the battery. I generally don’t leave it plugged in either unless we’re approaching 0F. In this case I also wanted to see how much energy it used.

The owner’s manual of pretty much every EV says to leave it plugged in either always, or when in extreme hot or cold.

Tesla says leave it plugged in always (in large bold
letters). And totally avoid -22F or colder except for short periods.

View attachment 321010

Polestar says leave it plugged in always, especially in extreme hot or cold.


View attachment 321023

Lucid says leave it plugged in always, especially outside of -4F and 113F

View attachment 321024

GM says leave it plugged in when outside 32F or 90F



View attachment 321025

Ford says to leave plugged in below freezing

View attachment 321032

Porsche says to leave it plugged in above 86F
View attachment 321034


It’s going to be nearly -40F here in northern Minnesota later this week.

For me it’s a balance between keeping the battery warm overnight and also getting better range when I depart in the morning, or don’t leave it plugged in and have less range and then have to DCFC sooner and longer. With DCFC prices, keeping it warm overnight on cheap off-peak rates at home is probably cheaper than extra DCFC usage.

Understood, but I literally never can accomplish that, just charge when I need to. I have never left any unattended battery conditioning on, but that's because I couldn't leave it like that unplugged for 3 days.

 

[CleanSump]

This has been very educational for me. Thanks everyone for your input. I'm fairly sure there's an EV in my future.

 

[JeffKeryk]

This has been very educational for me. Thanks everyone for your input. I'm fairly sure there's an EV in my future.

Each use case is different. Mine is pretty EV-optimal. The best points are charging at home with solar panels instead of expensive CA gas. Both the Model 3 cars I've owned are flat out fun to drive.
The negative is probably the cost to insure. I did talk to my insurance company (thru Costco) and they told me all rates took a jump, not just EV. But please talk to your insurance company first! As for home charging, make sure your service panel can accept a dedicated 240v circuit. A new panel ain't cheap.

Drive a bunch. If you like futuristic stuff, Tesla is great, but they are not for everyone. Many will be better off with a more traditional car based EV.

I do suggest considering the idea of a "pure play EV" as otherwise it is a compromise. Not necessarily bad, but not optimal. There will be more EVs coming. Good luck.

 

[demarpaint]

I remember a couple years ago people in Chicago were stranded in the city because they couldn't take a charge/waiting in line to charge because of the very cold weather. Whats different here? What am I missing?

+1 This coming weekend looks like it could be a repeat for a lot of people, especially for those who can't leave their cars plugged in.

 

[Torrid]

+1 This coming weekend looks like it could be a repeat for a lot of people, especially for those who can't leave their cars plugged in.

I'll definitely let you know what happens. My car will not be plugged in sitting in a parking lot with -50F windchills which is out of my control. It's at 54% now and has to make a 40 mile drive whenever I get back to it. When it was at its coldest last year I was driving 150 miles round trip charging to 80% and returning around 15%. That whole week was at -20F pretty consistently.

 

[demarpaint]

I'll definitely let you know what happens. My car will not be plugged in sitting in a parking lot with -50F windchills which is out of my control. It's at 54% now and has to make a 40 mile drive whenever I get back to it. When it was at its coldest last year I was driving 150 miles round trip charging to 80% and returning around 15%. That whole week was at -20F pretty consistently.

No worries, I'm sure if there are problems it will make the news like it did last time.

 

[Torrid]

No worries, I'm sure if there are problems it will make the news like it did last time.

I'm just curious the scenario. It will happen again. People fail to plan ahead with many things in life. I'm sure the majority only public charge and try to charge first thing when leaving. When it's that cold its just not going to take much charge until it warms up. It sucks that it's not as simple as filling with gas, but most of it is user error. For example when I do get back and make my 40 mile commute I'll plug in when I first get home. It'll be able to start charging while the battery has some heat in it.