Preconditioning Tesla Battery prior to Supercharging
When supercharging the battery it is recommended to be preconditioned on the way to the supercharger by simply selecting navigation, and choosing the supercharger planned for charging. Select the charger well in advance 10-20 minutes prior to reaching the Supercharger. This will ensure the battery is ready to receive the higher charge. A complaint by some has been seeing a much lower level when connecting to a supercharger, that was probably caused by not preconditioning. Also, it is necessary to change to different charging unit if a very low charging level is occurring.
My Tesla is a Model 3 AWD LR 18 rims
My Tesla is a Model 3 AWD LR 18 rims
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In short, at highway speeds, in an RWD vehicle, preconditioning does not add a noticable amount of battery heating over just driving.
Now on an AWD vehicle, there should be a noticable heating affect due to the front motor that generally wont be doing anything to move the vehicle, just heating.
Preconditioning draws 4 kW which is less than cabin heating.
FISHEV doesn't know what he's talking about and has tried to say in the past that preconditioning used 8kWh over a 10 minute/11 mile drive. This would mean an average draw of an insane 48kW. This is simply not even in the realm of possibility.
Unless you did it last night you have no data to come to conclusions about RWD on route warm up at highway speeds. That is unless you are getting someone else's data.
Energy traces are charted over distance, so speed is the major influencer in production of Wh/m peaks. Slow or stopped traffic causes the biggest peaks recorded while fixed draws continue to accrue with little or no forward progress.
Preconditioning comes one when you NAV to a Tesla SC and battery is cold. It is apparently on at that point whether you are moving or not. The actual spec sheet on the battery heating says it will work whether car is moving or not so stopped at lights, etc. the Preconditioning is still on.
In our prior discussion it was pretty well proven that during the battery heating cycle the radiator is cut out of the coolant loop. https://ibb.co/mtbf68S Do you have data to show that once you start moving the cold coolant (~0C) that's been sitting in the radiator isn't now being dumped into the cooling circuit? That could be one explanation for the stator temp and the battery inlet temp dropping once you start moving.
I'm not saying it is. I don't have any way to test it, right now (test equipment coming soon), but do you have proof it isn't?
The OP's post is about preconditioning on the way to a supercharger. Not tooling around for a few minutes after you've preconditioned sitting still.
"In short, at highway speeds, in an RWD vehicle, preconditioning does not add a noticable amount of battery heating over just driving."
As of last night (Jan-10-2020) you stated you had no data to back that up. Until it's proven it's hypothesis.
Did you take it all the way to a supercharger, while pre-conditioning, and collecting data points, giving it a good 30 minutes at highway speeds allowing the car to do what on route battery warm up is designed to do? Have you collect any revenant data taking it all the way to a supercharger, while pre-conditioning, and collecting data points, giving it a good 30 minutes at highway speeds allowing the car to do what on route battery warm up is designed to do?
Which has nothing to do with the question about being in Park.
So let me ask you....if I precondition while standing still and get the stator temp up to say over 40C and then I start driving while still preconditioning..if the stator temp goes DOWN, and I show that the radiator is still bypassed, would you accept that that means that at least a portion of the preconditioning power has grown down as well?
I should be able to get you that data set pretty easily. I think I already have it but I would want to get a fresh sample with a greater drive time in there. Main values that would be recorded would be stator temp, motor power, speed, and radiator bypass. Additional values could be cell temp, inlet temp, outside temp, coolant flow rates....
Yes you can precondition while in park and while in hold. The message on the screen comes up but that means nothing. The CANbus data shows it actually is working by showing power being routed to the motor while stopped.
Preconditioning is up to 3.5kW PER motor. This is an important distinction to avoid confusion. FISHEV can't keep his numbers straight either. One day he says preconditioning on an 11mile 10 minute trip used 20 miles, another day it is 33. He never backed up his statements with the mathematical formulas to get to the preconditioning power(3.5kW per motor)
Secondly, in your tests are you driving at consistent highway speeds navigating to a supercharger for a good 30 minutes or so? Are you collecting data the whole way to a supercharger until you stop and plug in. Preferably one close to the highway, so you aren't doing a bunch of around the town driving between the highway and the supercharger.
Does the app have a snap shot mode? In other words can you set up a trigger, and it will log selected data points at X preset time before the trigger and X preset time after the trigger. Most OBD have a snap shot mode.
That in itself takes a lot of variables out of the picture. I really don't think you need to worry about variables though. There have to be millions of of different driving scenarios any car is going through, has been through, and is going to go through once the preconditioning icon pops up.
"So let me ask you....if I precondition while standing still and get the stator temp up to say over 40C and then I start driving while still preconditioning..if the stator temp goes DOWN, and I show that the radiator is still bypassed, would you accept that that means that at least a portion of the preconditioning power has grown down as well?"
I would have to assume so, but what does preconditioning at a standstill have to do with on route battery warm up?
Personally I think anything before the icon pops up is pretty worthless data except maybe a few minutes prior, so you can watch for changes in data points once the icon comes up.
Sure data before the message pops up means nothing. It comes up right away though whenever I rout to a supercharger.
You are missing the point...I am never actually going to a supercharger, just routing to it to turn on preconditioning. I am usually going in the general direction of the SC though.
The app has a logging on or off for the current tab you have open. The data on that tab is fully configurable. I could log ALL the PIDs available in the app but that is a lot of unneeded data. And I am working in excel and not using VBA so I can only deal with so much data at once.
I maintain that on-route battery warm up is just a name. If I route to a supercharger and get the precondition message I maintain that that is the same thing. Could there be a difference, maybe but I doubt it. If you really wanted to go there I could just stay in hold mode instead of Park..
Preconditioning at a standstill will get the stator temp up the fastest in order to show the temp drop when starting to move...at highway speeds.
Public Service Announcement:
FISHEV is a known troll of several years standing and several user
names who pushes an anti Tesla narrative. Please
take his opinions with a grain of salt, avoid any advice he may
suggest, and do not let him implant any Fear, Uncertainty, or Doubt
about Tesla or your car into your own opinion.
Using the demo of the app that datapoint is labeled "Radiator Bypass", but the value in the other column can be from 0% to 100%. It's going to always say Radiator Bypass, The percentage of bypass is variable. If your not getting the percentage of bypass you're not getting the correct data.
"I maintain that on-route battery warm up is just a name"
I guess you didn't read those update notes: https://ibb.co/TkJ5bs1
And if you don't actually perform a full on route battery warm up you're never going to get the correct dataset.
"You are missing the point...I am never actually going to a supercharger, just routing to it to turn on preconditioning. I am usually going in the general direction of the SC though."
If you are trying to prove or disprove the effectiveness of "on route battery warm up" you need to drive far enough at highway speeds, preferably before the icon has popped up, and then log data all the way to a supercharger after the icon pops up, or you haven't collected the correct data and/or all of the data. You'd just be guessing.
You have to duplicate what your trying to prove, not half duplicate what your trying to prove.
This is why I'm purchasing my own equipment.
Haha that is funny cause that release note doesn't say anything about being required to be in motion. It just says you have to "navigate to" a SC which you can do in park.
Again you are missing what I am saying and ignoring scientific process. If I say that a process uses 100kWh in an hour, do i need to get data for the entire time period to reasonable prove or disprove that? Not if it is supposed to be a constant draw. But if the draw is NOT constant and goes down at a certain speed then...ohh yeah that is what I am saying. So I dont need to get the entire time period, I only need to show that the heating ability goes DOWN due to speed to prove my theory.
I can't wait till you get your own equipment, will be nice to have more data.
Remember my claim is that the preconditioning heating capability goes down at highway speeds. The only thing I need to prove that is to show stator temperature vs speed. Time means nothing though it is inferred by speed as is distance. All this with preconditioning on.
That's what I thought. Knew it did in hold as I see that all the time. Couldn't see any reason for NAVing to SC and being in Park.
"In short, at highway speeds, in an RWD vehicle, preconditioning does not add a noticable amount of battery heating over just driving."
Basically that RWD has no Preconditioning which would make no sense. 340hp motor could generate a ton of waste heat so no reason a RWD car would not have Battery Preconditioning functionality. They certainly need it as much. Nothing from Tesla says no Battery Preconditioning for the RWD cars.