Preheating battery in cold weather use.

[ruby110]

One thing you don't mention is your SoC the second time you charged at that SC. There is a charge rate curve that varies depending on the SoC of the battery. So if your SoC was only 15% when you returned you would see a faster charge rate. Once you hit 80% it slows down quite a bit. So on a road trip you're usually better off running the battery down and charging just what you need to get to the next SC rather than charging to 90% to reduce stops. For example, if you have the option of charging to 60% and stopping at the next SC or charging to 90% and stopping at a second SC that's 100 miles further away, you're better off doing the lower charge and stopping again at the second one for another quick charge.

Sorry for delayed response.

I don’t recall the the precise SOC but I think it was around 55%. We are aware of the charging strategy you suggest but it’s not for us. We are retired and have the time to charge to levels which provide margin. In the almost 4 years driving Tesla’s across the country we have experienced closed or unavailable Supercharges multiple times.

 

[evJOULE]

Have you tried the Tesla site to demo trip planning: Go Anywhere | Tesla

It isn't the same as what it in the car, but it is a start.

Thanks @MP3Mike, I tried your suggestion and was surprised to see the Tesla app nearly triple the time. The EVTO-Tesla app was set for fastest time mind you...

... pictures not uploading properly. Will try a second post below.

 

[evJOULE]

More pictures?

 

[evJOULE]

and more...

 

[evJOULE]

Third times a charm... Sorry had a problem with file format...

 

[evJOULE]

Not sure if it is just my browser, or if the pictures didn't upload correct. Anyway, the Tesla app suggests 55 minutes of charge, while the EVTO-TESLA app proposes 20. Anyone know how reliable the EVTO app is? Can a Model 3 driver trust the suggested charge stops and times in the app?

 

[M109Rider]

I’m resurrecting this summertime thread, because winter here in Canada is just around the corner.
Given that I want the most longevity from my model 3 AWD, I’m wondering if there is any new and difinitive information around how the model 3 heats the battery when it’s -10 to -25 out.
If I had a choice, (in the interest of keeping the battery happy, warm, and healthy all winter long), I would set the model 3 to turn on an internal battery heater when temps got below zero celcius, but I know of course this isn’t a feature and isn’t possible.

Seems to me, the best way is to set it to finish charging from say 80% to 90% just before leaving the house.
This doesn’t help, if it sits at work all day though.
In the limited time I’ve had the car in somewhat cool temps, I feel turning the internal heater on before leaving doesn’t have a huge affect on heating the battery much. That being said, I haven’t left the heater on for more than about 15 - 20 minutes, maybe leaving it on longer is the next thing I should try. Checking regen dots after a long cabin heat, should answer the question.
Still, like “ev JOULE” stated, it’s not best way to keep the battery warm. Heating the cabin, when all you really want to do is just heat the battery.

 

[Rocky_H]

@M109Rider, There isn't really a benefit to the car. You're really treating yourself, as I have heard people say. The chemical reaction of lithium ion batteries don't have much problem with discharging down to very cold temperatures. It's the recharging process that is potentially harmful and needs to be very restrictive about cold temperatures. So you would be using up a lot of energy just so that it can be warmer to be able to receive regen energy? That's just a big waste.

If you are at a place where the car is plugged in, then sure, there are a couple of things you can do, but the purpose of that is just so that you can do some of it with outside energy to keep more range in your battery for your drive, rather than just having huge energy usage for the first several minutes of your drive. The car isn't really going to care either way.

 

[M109Rider]

@M109Rider, There isn't really a benefit to the car. You're really treating yourself, as I have heard people say. The chemical reaction of lithium ion batteries don't have much problem with discharging down to very cold temperatures. It's the recharging process that is potentially harmful and needs to be very restrictive about cold temperatures. So you would be using up a lot of energy just so that it can be warmer to be able to receive regen energy? That's just a big waste.

If you are at a place where the car is plugged in, then sure, there are a couple of things you can do, but the purpose of that is just so that you can do some of it with outside energy to keep more range in your battery for your drive, rather than just having huge energy usage for the first several minutes of your drive. The car isn't really going to care either way.

I do understand what you’re saying. You could be right.
However, based on everything I’ve read, I’m just not convinced driving while the batteries are -5 to -10 celcius on a daily basis is very good for the batteries longevity.

I suspect Tesla batteries that live in Vancouver, Washington, or Oregon, would likely last longer than batteries that live in Ontario. Again, just my opinion.
If there was a better way to heat the battery before driving during the winter, I would suspect there is benefit to the car. I know you believe otherwise, but there is no formal data proving this either way that I’ve read.

I know the Tesla battery engineer (can’t recall his name) stated Vancouver Canada is a perfect climate for electric vehicles, because they don’t have heat or cold extremes in that climate. Summer generally sits in the 70’s and winters generally sit in the low 40’s. (Fahrenheit)
I doubt he made that comment, strictly because it was easier on the cabin occupant. I suspect that comment had more to do with how it impacts the battery.

Anyway. I noticed that when I get in a cold car, and make a number of fast runs, it definitely heats the battery up quicker.
Not sure this is a healthy way to warm the battery on a daily basis, but again, I don’t know.
Tesla spent a lot of money to make systems that manage the temperature of our batteries.
I’m sure if Tesla could magically keep them warm all the time during winter, it would be ideal. The cost to keep them warm all winter like that would be scary, but the cost to warm them up effectively before use would be acceptable to me, to keep the battery healthy.

 

[Rocky_H]

I do understand what you’re saying. You could be right.
However, based on everything I’ve read, I’m just not convinced driving while the batteries are -5 to -10 celcius on a daily basis is very good for the batteries longevity.

I suspect Tesla batteries that live in Vancouver, Washington, or Oregon, would likely last longer than batteries that live in Ontario. Again, just my opinion.
If there was a better way to heat the battery before driving during the winter, I would suspect there is benefit to the car. I know you believe otherwise, but there is no formal data proving this either way that I’ve read.

There basically is data proving this, as Norway has had the largest % market penetration of electric vehicles for many years.
The guy who owns the most Teslas in the world lives in the Arctic Circle
Tesla just became the most popular carmaker in Norway – where 32% of all cars are electric
Electric vehicle sales achieve new record in Norway with 45% of new cars being all-electric and 60% plug-in

 

[M109Rider]

There basically is data proving this, as Norway has had the largest % market penetration of electric vehicles for many years.
The guy who owns the most Teslas in the world lives in the Arctic Circle
Tesla just became the most popular carmaker in Norway – where 32% of all cars are electric
Electric vehicle sales achieve new record in Norway with 45% of new cars being all-electric and 60% plug-in

No offence, but you didn’t cite any data proofing anything. You just added links to Norway’s EV growth.

I was looking for ways to best warm the battery, because I feel cold winter temps are not good for lithium batteries.

 

[SSedan]

Last winter I only had a 30amp hookup, now I have a 100amp connection have been keeping it set to 42-50amps and that level of charging has sofar seems to provide heating above what the pack heater does. Now granted it has only been down around 30f so not real cold yet but I am very optimistic about higher amperage charging being better in winter.

Now I will admit it is possible one of the updates changed the battery warming parameters and I am misattributed it to the charging amperage.

 

[Kermee]

I’m resurrecting this summertime thread, because winter here in Canada is just around the corner.

I was looking for ways to best warm the battery, because I feel cold winter temps are not good for lithium batteries.

Under the "Battery Care" section on page 111 of the Model 3 Owner's manual, it states:

Temperature Limits

For better long-term performance, avoid exposing Model 3 to ambient temperatures above 140° F (60° C) or below -22° F (-30° C) for more than 24 hours at a time.​

I have had my Model 3 parked at or near 0° C ambient for a while once a few weeks back. Upon entering the car, the Power Consumption Bar (the one that turns green when your regenerating, and black as you're consuming power), was fluctuating into the black with the car in idle (Parked) while connected to my UMC2. My assumption is that the motor was running, with no torque, to generate heat to either warm the batteries or to keep them warm.

Short of keeping the vehicle garaged or parked for long periods in more favorable ambient temperatures, I don't think there's much you can do except let the BMS handle keeping the batteries in their best state. My assumption is that once the ambient temperature reaches -30° C, the heat generated by the motor can no longer sustain keeping the batteries warm enough for an extended duration or the amount of no-torque power it's able to produce will quickly deplete the batteries.

 

[David99]

Given that I want the most longevity from my model 3 AWD, I’m wondering if there is any new and difinitive information around how the model 3 heats the battery when it’s -10 to -25 out.
If I had a choice, (in the interest of keeping the battery happy, warm, and healthy all winter long), I would set the model 3 to turn on an internal battery heater when temps got below zero celcius, but I know of course this isn’t a feature and isn’t possible.

Seems to me, the best way is to set it to finish charging from say 80% to 90% just before leaving the house.

as mentioned, driving with a cold battery isn't an issue for longevity. The car will heat the battery if it gets too low when you drive or charge. Regenerative braking will be reduced by a cold battery but that's not a problem that causes degradation.

Dame for charging in cold temperatures. The car will reduce the charge rate if it gets too cold. Under 0 C the battery can't be charged and needs to be heated first.

I have had a few winters with my S and reading the CAN bus I was able to see the battery temperature. A common misconception is that people assume ambient temperature and battery temperature are the same or close. They are not. Normal driving brings up the battery temperature quite a bit. Even leaving the car parked outside over night will not bring the battery temperature down to the ambient temperature. For example I came back at 6 pm with a semi warm battery. At night it dropped to -25 C. In the morning I checked the battery and it was at -8 C. That's perfect fine to drive. I turned on the cabin heater (which also activated the battery heater). It took about 25 min to bring the battery back to 0 C. Another 10-15 min to get it to 9 C at which point the car stops using active battery heating.

While there is no negative effect to start driving with a cold battery, the car will use a lot of extra energy to warm up the battery when it's very cold. This is lost energy. When you do this while you are still plugged in at home, that energy comes from the grid. Basically you will have 30-50 more miles if you pre-heat your battery at home before you leave.

You can either use the charge timer, use the app to preheat the car manually in the morning or (that's what I use) use an app called 'Dashboard for Tesla'. It has a pretty sophisticated smart charge feature. It automatically calculates how long charging and cabin heating will take and start the charge process in time so it finishes just before you leave in the morning.

 

[evJOULE]

I’m resurrecting this summertime thread, because winter here in Canada is just around the corner.
Given that I want the most longevity from my model 3 AWD, I’m wondering if there is any new and difinitive information around how the model 3 heats the battery when it’s -10 to -25 out.
If I had a choice, (in the interest of keeping the battery happy, warm, and healthy all winter long), I would set the model 3 to turn on an internal battery heater when temps got below zero celcius, but I know of course this isn’t a feature and isn’t possible.
Seems to me, the best way is to set it to finish charging from say 80% to 90% just before leaving the house.
This doesn’t help, if it sits at work all day though.
In the limited time I’ve had the car in somewhat cool temps, I feel turning the internal heater on before leaving doesn’t have a huge affect on heating the battery much. That being said, I haven’t left the heater on for more than about 15 - 20 minutes, maybe leaving it on longer is the next thing I should try. Checking regen dots after a long cabin heat, should answer the question.
Still, like “ev JOULE” stated, it’s not best way to keep the battery warm. Heating the cabin, when all you really want to do is just heat the battery.

Thanks for adding your thoughts M109Rider! It seems that some of the confusion for me at least, or lack of understanding maybe, could be eliminated if Tesla would clarify the needed information pertaining to this subject. The fact that Model's S and X have a slightly different battery heating system seems to offer hints or clues as to what might happen, but it doesn't quite reach a conclusion for me. I would like to see Tesla add a section to the Model 3 owners manual detailing battery heating/cooling parameters and the inputs needed to active them. It would be nice to know for example if I leave my car parked outside in -25 Celsius weather over the weekend while plugged-in, will the battery management system periodically warm the battery without using the car for 48 hours, or do I have to set the car to preheat the cabin for 20 minutes every eight hours or so to activate it? And does preheating the cabin even activate it? That seems to be the case with Model's S and X, but I haven't seen anything official other than the generous input form Model S and X owners. And what happens if the car sits outside in the same weather conditions unplugged for extended periods of time like at an airport? Does the BMS keep the battery warm, and for how long can it do that without being plugged-in? For me, these practical aspects of owning what has turned out thus far to be the best car I have ever purchased shouldn't be so difficult to answer. It is funny how brand loyalty, or pride of ownership would cause some to misinterpret what is a genuine interest to take better care of the thing we all have pride of ownership in.

 

[Rocky_H]

@evJOULE It's the K.I.S.S. principle, though. You know how most people are when they see that some thing has several pages of detailed instructions. They get scared of it, thinking it's too complicated to use, and that since it has such detailed care instructions that if they don't do something just right, they are going to accidentally destroy it. They would rather have something that just has a couple of easy steps and otherwise just takes care of itself.

Tesla sure doesn't want people to be scared of buying its products, so they've intentionally made it simple. Following detailed procedures is not necessary, and they don't want people worrying all the time if they're doing something wrong.

 

[evJOULE]

as mentioned, driving with a cold battery isn't an issue for longevity. The car will heat the battery if it gets too low when you drive or charge. Regenerative braking will be reduced by a cold battery but that's not a problem that causes degradation.

Dame for charging in cold temperatures. The car will reduce the charge rate if it gets too cold. Under 0 C the battery can't be charged and needs to be heated first.

I have had a few winters with my S and reading the CAN bus I was able to see the battery temperature. A common misconception is that people assume ambient temperature and battery temperature are the same or close. They are not. Normal driving brings up the battery temperature quite a bit. Even leaving the car parked outside over night will not bring the battery temperature down to the ambient temperature. For example I came back at 6 pm with a semi warm battery. At night it dropped to -25 C. In the morning I checked the battery and it was at -8 C. That's perfect fine to drive. I turned on the cabin heater (which also activated the battery heater). It took about 25 min to bring the battery back to 0 C. Another 10-15 min to get it to 9 C at which point the car stops using active battery heating.

While there is no negative effect to start driving with a cold battery, the car will use a lot of extra energy to warm up the battery when it's very cold. This is lost energy. When you do this while you are still plugged in at home, that energy comes from the grid. Basically you will have 30-50 more miles if you pre-heat your battery at home before you leave.

You can either use the charge timer, use the app to preheat the car manually in the morning or (that's what I use) use an app called 'Dashboard for Tesla'. It has a pretty sophisticated smart charge feature. It automatically calculates how long charging and cabin heating will take and start the charge process in time so it finishes just before you leave in the morning.

Thanks for your insight David, much appreciated. I wonder if you aren't missing the main point behind the question I was asking though. The question was not really about driving the car in cold weather, or even charging it. It was more about preheating the battery in the Model 3, and if there are any recommendations for extreme cold weather use. The reason I was asking is because the Model 3 uses a different method to warm the battery then the Model's S and X, and I live a little bit North of Orange County, California if you know what I mean.

Although I do appreciate the view point you are passing on, I would be interested to know where you get your information regarding battery longevity and cold weather use. The Model 3 is still relatively new in terms of battery chemistry, so any technical information you have on this issue would be helpful. My understanding is that extreme temperature swings, rapid discharges, and deep cycling are all things that have been shown to play havoc with Lithium batteries. We can use the first Gen Leaf as the case study in what happens when you don't use good thermal regulation, and I think it is safe to say that goes for both high and low temps. So I am not really sure what you mean when you say "driving in cold weather" isn't an issue. Having the battery warm up and cool down each day is probably not the ideal when compared to a car used in a more temperate climate.

But you gave a great example of how the Model S works in California, and I have to assume you were not in Orange county when it hit -25C. I get how you can use the Tesla app to pre-heat the cabin and see whether the battery is also being heated, unfortunately that is not how the app works for the Model 3... hence the all the questions. In fact, I am still not even sure that pre-heating the cabin has anything to do with heating the battery... hence all the questions. I like your idea on reading the CAN bus though, and will have to look into how I can do this with the Model 3.

 

[CapnOMatic]

Thanks @MP3Mike, I tried your suggestion and was surprised to see the Tesla app nearly triple the time. The EVTO-Tesla app was set for fastest time mind you...

... pictures not uploading properly. Will try a second post below.

Based on that route I believe there is another Tesla supercharger in New Rochelle, NY. I would recommend you consider stopping there before heading into the City just in case you hit a lot of traffic or other situations, busy chargers etc.. Have not visited any of the chargers in NYC Manhattan area, but from the map, it only looks like there are two supercharging stations in lower Manhattan, NY. One has only two chargers and the other has only two. Not a lot for a large congested city in lower Manhattan.

 

[Kermee]

Found this gem that was posted a while back...

Source: Model3OwnersClub

Consensus seems to be:

• As long as the ambient temperature doesn't drop below -30C for longer than 24 hours, the car will take care of the battery itself. Otherwise, find somewhere warmer to park it.
• If you don't pre-heat the battery, you will definitely have reduced range or much slower charging until the battery warms up.
• If you want to pre-heat the battery, just switch on cabin control at least an hour before you head out, preferably hooked up to "shore" power.

The Model 3 is still relatively new in terms of battery chemistry, so any technical information you have on this issue would be helpful.

Battery chemistry is virtually the same. It's still NCA, but with further reductions in cobalt. Source: Two Bit da Vinci via InsideEVs

Also, I think you took @Rocky_H's post a bit too personally. He (or she) wasn't attacking you. Basically his argument, extrapolated, was a generalization is that Tesla is building vehicles for the mass consumers and it should be as simple or easier than owning an ICE vehicle, or actually even worry less than one. We're all here to help each other and answer to the best of our abilities. Here are some of the questions you asked:

• [F]or example if I leave my car parked outside in -25 Celsius weather over the weekend while plugged-in, will the battery management system periodically warm the battery without using the car for 48 hours, or do I have to set the car to preheat the cabin for 20 minutes every eight hours or so to activate it?
• And does preheating the cabin even activate it?
• That seems to be the case with Model's S and X, but I haven't seen anything official other than the generous input form Model S and X owners.
• And what happens if the car sits outside in the same weather conditions unplugged for extended periods of time like at an airport?
• Does the BMS keep the battery warm, and for how long can it do that without being plugged-in?

He (or she) is basically pointing out that you shouldn't have to worry about any of these conditions other than what was stated in the manual of extreme temperature. To answer your second question, yes. Preheating the cabin will also activate the Model 3 heater, if the BMS determines it is needed as you can see from the image above.

3rd question is answered in the manual on Page 44 for the Model 3. It has the same verbiage as the Model S/X owner's manual:

4th and 5th question, it would be the same for any of the Tesla models. It's up to the BMS to make sure the battery stays healthy. But back to Rocky_H's extrapolated point of "K.I.S.S.", the manual says as long as the vehicle is in an ambient temperature higher than -30C, the vehicle should be fine. I've left my car at an airport for 5 days, unplugged in very cold weather, and it was fine when I got back minus a bit of vampire drain. Does leaving a lithium battery in cold weather affect the longevity? From my previous academics, it's negligible until certain extremes (i.e. colder than -30C for Tesla) and mostly occurs if you try to PULL or PUT too much into the battery (hence the no regen, slow charging, power-limited/slow acceleration). If the battery is basically not being used, there should be little to no degradation, in terms of longevity, at all to it.

Hopefully, some of this will help put your mind at ease and not to sweat it too much. And if there are any more definite answers to your questions, I'm sure they will surface up and provide more information.

Cheers.

 

[1deepthink]

@Kermee, this is one of the best posts I’ve read! It’s informative, measured and shifts the conversation back to helpful from angry. Thank you!