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Preconditioning is not the same as getting the car ready for supercharger?
- Thread starter E46M3
- Start date
E90alex
Active Member
The battery needs to be much warmer than normal for maximum supercharging. This is only done when you enter a supercharger into the navigation and it’s far enough away to heat the battery sufficiently.
Regular preconditioning only prepares for normal driving so you have better power and better regen. Note that the cabin warms up much faster than the battery so even if you precondition and the app says desired temperature is reached, the battery still might not be warm enough to provide full regen.
Regular preconditioning only prepares for normal driving so you have better power and better regen. Note that the cabin warms up much faster than the battery so even if you precondition and the app says desired temperature is reached, the battery still might not be warm enough to provide full regen.
I've noticed that doing nothing more than turning on Climate when it is cold (below freezing), pulls down the maximum 48 amps for a while. If it is below 0ºF (-18ºC) it will pull maximum current for quite a while (hours). But it sure does reduce initial battery drain after departing.
E90alex
Active Member
Yep it’s trying to heat the battery to optimum operating temperature even after the cabin has reached temp.
It doesn’t tell you when the battery as reached optimum temperature though as it can take a while depending on how cold it is and it doesn’t want people to be waiting hours for the battery to warm up thinking they can’t drive it until it’s warm.
The weather has been so cold the last few months that even when I’m preconditioning to a SuperCharger that’s a 45 min drive away the cold has been constantly giving warnings that the battery is too cold and I should precondition next time.
In all the many years these last few months are the only time I’ve been getting these.
So funny to me that I’ve got the HVAC on high, seat heaters on, radio blaring - even after nearly an hour drive during the middle of the days it’s still coming up
In SoCal so not nearly as cold as much of the country.
In all the many years these last few months are the only time I’ve been getting these.
So funny to me that I’ve got the HVAC on high, seat heaters on, radio blaring - even after nearly an hour drive during the middle of the days it’s still coming up
In SoCal so not nearly as cold as much of the country.
This clear, concise, and helpful answer stuff has to stop. Do you not know you're on the internet? There are rules man! First you have to insult the poster, then go on a rant about how silly the whole topic is, and finally you close with something completely wrong, or at least off-topic.
What a rookie...
Seems like a complicated topic, so let me ask a question in the hopes you can steer me correctly.
Scene:
Will be wife's car. Garage kept, never below 50F in the winter. On the other hand she leaves work at 0F oft enough, and at random times.
Question:
How long before she departs should she launch precondition such that the battery is warm enough to not cause undue drain (really harm to battery, which I infer is the same)?
Thanks for any insight you can share.
We're discussing optimum use scenarios here. There actually is no need to wait to drive. Unlike an ICE vehicle which operates much better when warmed up. A Tesla (or other EV for that matter) does not need to warm up before use. However, if you know in advance when you are heading out, and the vehicle is plugged in to shore power, an extra hour of Climate being on is helpful. It reduces the battery charge consumed by heating the battery before you leave, using shore power If you are not plugged in, then don't worry about early heating beyond creature comfort.
One of the things that surprised me, is how much energy the car pulls down during a heating only session. Iy pulls down a full 48 amps at 240V, if available. But the car does not report consumption for heating anywhere. I did not realize it until I installed an energy monitor and connected it to my 60 amp charging circuit. I turned on the heat, and saw the consumption move up to 12kw.
The car will heat itself up when you are driving. But it will consume less energy if the battery already warm when you leave. So only do the early heating when you are plugged in.
First off, there is no harm to the battery in either scenario. if it is bitter cold outside (0ºF). If you turn climate on say for an hour before she leaves, it may reduce energy consumption while she is driving, as long as the car is plugged in. The app will tell you when the battery heating is happening, with the snowflake displayed. If your garage is truly 50ºF, that may be enough. But it won't hurt to turn climate on if the car is half warm already. It also somewhat depends on how much she needs every last drop of energy. My typical day uses less than 10% of capacity, so it is not really a big deal. But if she needs 80% to get through the day, it might be helpful. It could avoid a mid day charging stop.
In the new version of the energy graph, there is some statistical information provided giving you an idea how much energy is consumed by heating vs other operating conditions. But TBH, I haven't spent much time in there with the data.
YMMV.
So the "don't worry about harming the battery" point has been sufficiently repeated already, but FYI (because you may never experience this), the top side of the IC energy chart (draw side) can show dashed lines the same way the bottom side (regen side) does when the battery is fully charged or cool enough to merit limiting regen. I should imagine this would occur in any scenario where limiting power consumption is merited. To be clear, I'm not sure I've even seen this in mine, but I've at least seen a picture showing it somewhere some time ago.
50ºF is not warm enough for full regen, but AFAIK, preconditioning doesn't target full regen (or even as much regen as is already available at 50ºF, so turning on climate won't help with that. One can schedule charging so that the battery will be warm enoug for full regen, though. OTOH, if you meant so that the vehicle is already heated and not using more energy to heat right at the beginning of the drive, then pardon me, as you ae correct, adding another 10ºF of so to the cabin from shore power certainly won't hurt.
Your confusion is understandable because Tesla did something really legitimately confusing here. They used the same word "preconditioning" to mean two totally different things in different contexts, which have two different functions.
"Preconditioning" while the car is parked is like for warming up the cabin. And if the battery is really cold, like below freezing, it will also warm the battery up some to get it to a medium temperature, which is a bit more comfortable for your driving, so your regen doesn't feel really limited.
But that is not the same thing as "preconditioning" for Supercharging. That previously mentioned kind of warming up to medium temperatures while parked isn't nearly enough for fast Supercharging speeds. That needs to get HOT. And that only happens while the car is in Drive gear, and the navigation is set to go to a Supercharger. In that condition, then the word "preconditioning" means it is blasting the battery heating to get it as hot as it can to make Supercharging really fast.
henderrj
Active Member
So, same idea but to a much higher degree? (Both meanings of that word.)
Just thinking here, but we could say that preconditioning before traveling saves battery usage, by not having to use battery energy to heat itself up sufficient to operate normally. Whereas preconditioning for faster supercharging actually uses up battery capacity for the sole purpose of increasing charging speed once you get there. I do wonder, strictly curiosity here, how much charging time is increased due to the battery capacity tapped for heating, as opposed to decreased via the speed of charging. Do we know if anybody has actually calculated that?
And, are we actually aging the battery prematurely by cycling it more doing this preconditioning for supercharging?
Again, just academic questions. Probably not of any great importance.
henderrj
Active Member
If you are talking 240 volt I would think it would be enough. But also I think Tesla lets the battery drop a little below the charge point before starting it back up, it might even be 2%. Try popping the charge up just a little bit when you start the preconditioning. Or, depending on the app nowadays (I can't remember if it's still there and my car is in service so I can't check) you might be able to just hit "start charging".
doghousePVD
My grandfather’s car
I only get the message when navigating to a SC and it is very cold, near freezing or below.
