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Temps, Precondition, Regen data with GRAPHS

Temps, Precondition, Regen data with GRAPHS

The following tests were done on my Long Range RWD Model 3.

PRECONDITIONING
* https://imgur.com/a/K16n8vB Time is in seconds, Temperatures are in Celsius. This was a short 3 mile drive, speeds up to 60mph. In the graph notable points are: R Stator temp plateau is me stopped in McD's drive-through. Temperature increases at the end was me initializing Battery Preconditioning(by routing to a supercharger). I would have let it go a while longer but turns out watching Netflix deactivated the routing which in turn deactivated preconditioning, and sorry but watching Netflix on my lunch break was more important then further data.

* Here are two graphs and one spreadsheet. https://imgur.com/a/p2rLlKS First one is my first 6 minutes driving this morning, no HVAC, no Battery Preconditioning. Second is next 10 minutes not in motion, no HVAC, Battery preconditioning ON. I then turned on HVAC, turned off BP, and finished my drive to work(about 10 min of 45-50mph with stop lights, 15 min highway 60-75mph, 5 min <20mph). Temp data after I got to work is in the table in the 3rd pic. Speed in Graphs is in km/h here.

CABIN HEATER
*Heater power vs Time https://imgur.com/a/rPYkW0a This is heater + fan + misc power draw with HVAC set to Auto and HI for temp. This is just a first run. What I really want is to see it spin up and then drop back down when cabin reaches set temp.

REGENERATIVE BRAKING
*Regen vs Time with speed data, 70-0mph. https://imgur.com/a/oIR8qTw

*Full vs Limited Regen 70-0mph. https://imgur.com/a/Z7R88ge So this is a graph that overlays full regen 70-0mph and limited regen 60-0mph. By limited I mean the battery was at about 13C and my Regen bar was about half full of dots. Mental query: I wonder if supercharging speeds would be limited to what the maximum regen level is, on the Limited Regen line(~ 30kW)

*Hold mode vs Roll mode Regen graph. https://imgur.com/a/EIdPpnV This is a preliminary test showing that the regen profile from ~70-0 is not different between the New HOLD mode and Roll modes. This is preliminary because I was right on the hairy edge of having full regen available. As soon as I let off the accelerator, I got some regen limitation dots. Both of these runs were back to back and completed in a total time of 66 seconds.

ANECDOTES
"Starting" your car from the Tesla app, when the nav has been set to go to a supercharger does NOT start battery preconditioning.

jallred | 13. marraskuu 2019

Sweet. Thanks!

Bighorn | 13. marraskuu 2019

How refreshing. Actual data.

derotam | 13. marraskuu 2019

Excel can only have 1,048,576 rows by the way, guess I'll need to work on another way to graph longer time frame stuff

derotam | 13. marraskuu 2019

I'm going to try and keep updating the OP with various test. I'll try to keep them simple in explanation to avoid clutter in the post. Questions can always be asked, and there will usually be more data available that isn't graphed.

SamO | 13. marraskuu 2019

Ah the sweet smell of facts . . . thanks.

jallred | 13. marraskuu 2019

Those hot stators weren't doing much to the cell temp.
Looks like you had more impact on the outside temperature then the actual battery.

Please be assured that I'm being silly.

derotam | 13. marraskuu 2019

Since I have been collecting data, I think I have gotten my stator up in the 50's.

derotam | 13. marraskuu 2019

updated OP OP for quick and dirty info on 32 mile 51 minute commute home.

Bighorn | 13. marraskuu 2019

I had a bug on my car once where all that data was on my Model S dash instead of the big clock and I recall that battery temp ran around 50C.

jebinc | 13. marraskuu 2019

Nice, thanks!

MAB1980 | 13. marraskuu 2019

Physically, what is the battery inlet?

Is the system essentially a radiator sandwiched to the battery pack, with the inlet being where the thermal fluid enters the system?

derotam | 13. marraskuu 2019

Not exactly sure the exact position but perhaps there is a sensor just inside the pack where the coolant enters the pack.

derotam | 13. marraskuu 2019

Maybe it is listed in the parts catalog....I'll have to try and look.

MAB1980 | 13. marraskuu 2019

And sorry I shouldn’t have said “system;” I realize it’s closed loop. Meant where it enters the area of intended heat transfer.

jallred | 13. marraskuu 2019

I'm not sure where the battery inlet temp sensor is, but the temp is going to be the same from the bottle to the battery. Look up "tesla super bottle" and you can learn a lot. It is very well engineered. Other car companies will buy valves from some company and heat exchangers from another, etc. Tesla makes a good bit of this stuff themselves.

This is why Tesla rocks!

jallred | 13. marraskuu 2019

Anything on the CANbus that shows the state of the valve in the super bottle? I'm wondering if we can figure out how the coolant is flowing through the loop.

I would think in your case today that no coolant was flowing through the radiator. It looks like it was trying to heat its battery the entire trip. Outside ambient was keeping it low.

MAB1980 | 13. marraskuu 2019

@jallred thanks, I hadn’t seen that before.

Looked up super bottle and found this diagram; essentially what I’d pictured. The inlet sensor could be at the restrictor

https://i.kinja-img.com/gawker-media/image/upload/c_scale,f_auto,fl_prog...

derotam | 13. marraskuu 2019

@jallred, if the battery is cool it will be routing the coolant through the drivetrain to pick up heat for the battery. I wouldn't say it is "trying" to heat the battery, not actively...just as a byproduct of heat from the stator.

jallred | 13. marraskuu 2019

I'm using trying to mean that the valve is set so no coolant goes to the radiator and the chiller is turned off. I didn't mean that they are intentionally creating heat. Sorry to confuse.

As long as the stator and/or the electronics is warmer than the battery, it can use the battery as the sink of heat in the system.

derotam | 14. marraskuu 2019

Updated OP, added Battery Preconditioning(not moving) vs driving with no BP

billtphotoman | 14. marraskuu 2019

Thanks for posting and the engineer in me likes data to backup (or correct) my intuition. The battery pack seems to have a lot of thermal inertia (no surprise there).

derotam | 14. marraskuu 2019

Yes it does. In addition to me wanting to get this data just to get the data, someone had mentioned in another thread that Tesla had effectively said that driving for 5 minutes would heat the pack more than preconditioning for 5 minutes. Clearly that is not an accurate statement with my data and I only have a RWD car. Imagine heating up two Stators to pump heat into the battery via preconditioning.

While heating the pack via normal driving would be more "efficient" in terms of not just wasting the energy, normal driving, in a RWD car, will not appropriately precondition the battery for supercharging, nor does it appreciably warm up the battery in an hour of driving at cooler/colder temps.

jallred | 14. marraskuu 2019

Your ambient temps are super low. Your conclusions about preconditioning with normal driving may be different on warm days.

derotam | 14. marraskuu 2019

@jallred, yes, I am trying to make cure I reference cooler/colder in my statements. In warmer temps, you would have a lower heat loss to the environment, but in regards to the temperature range where the car would like to heat up the battery before supercharging, preconditioning while stopped is going to beat out driving.

Now preconditioning WHILE driving vs just driving is a whole other dataset which is hard to get without a static track. I want to get a "consistent" baseline drive with no preconditioning and then do the same drive with preconditioning and compare. And the drive has to have different speeds also.

Bighorn | 14. marraskuu 2019

The driving vs battery preconditioning statement was flat out wrong.

derotam | 14. marraskuu 2019

@Bighorn: you are referencing Tesla's statement right?

Bighorn | 14. marraskuu 2019

I was referencing the poster who said battery preconditioning does less than driving to heat up the battery in another thread. She may have referenced a Tesla employee, I forget.

derotam | 14. marraskuu 2019

Yes, ok just wanted to clarify.

derotam | 14. marraskuu 2019

Bumping because of a few threads and posts that would be served by seeing this thread.

derotam | 15. marraskuu 2019

Added new Full vs limited Regen overlay graph to the OP, 70-0 full regen, 60-0mph limited Regen

derotam | 15. marraskuu 2019

Added Heater power vs Time to OP

calvin940 | 15. marraskuu 2019

Whoah derotam!

What will FISHEV do now confronted with actual data versus his terribly wrong statements and equally wrong Maths?

jallred | 15. marraskuu 2019

First regen 70-0 shows multiple modes the car is going through. Almost looks temporal, around 4-4.5 seconds. Note the periodic velocity changes. I don't think they are perceivable by driver. But different slopes on power curve for each mode.

Wondering why heater power has significant noise until something happens and noise disappears.

derotam | 15. marraskuu 2019

@jallred: Yeah so I don't necessarily believe that those really exist. Probably something with the recorded data. I do have to pull out occasional errors, like a speed reading that shows I am going 287 miles an hour.

I started to investigate those but I wanted to just get the full graph done. If they keep showing up I will investigate further.

With the heater data, yeah, again I am not going to really try and analyze that right now...I think it would be a very low return on investment of my time.

derotam | 15. marraskuu 2019

@jallred: your killing me... so on that 70-0 vs time, the Torque values show the same bumps... anyway....moving on for now, haha.

ReD eXiLe ms us | 15. marraskuu 2019

Wow. How refreshing! Turns out that Trolls are allergic to fact based commentary and discussion. Whodathunkit? Excellent!

hokiegir1 | 15. marraskuu 2019

@derotam - Interestingly, your graphs look very similar to the ones that come out of TeslaFi if you click into the drive data:
https://imgur.com/a/Z4Hh069

derotam | 15. marraskuu 2019

@hokiegirl: Yes, there is a lot of metrics that you can actually get using the API. I have never used TeslaFi and don't want to pay a subscription. Even though TeslaFi is always recording, that is A LOT of data to sift through to get what you want to look at. I don't need everything record. Just the applicable metrics for what I want to look at.

jallred | 15. marraskuu 2019

They are definitely real. The show up in each parameter.

For cabin heat, I'm going to make a guess that they PWM the resistive heat. Makes power draw happen gradually. But maybe most important if they slowly heat up that heater they maybe can prevent it from making pinging noises as the metal expands. I heard that last winter but haven't heard it yet this fall.

Not sure why I'm killing you. As in funny, annoying? Just making observations that hoping someone can find useful.

derotam | 15. marraskuu 2019

...for making me go back and look at those anomalies. haha.

Magic 8 Ball | 15. marraskuu 2019

I don't think it is PWM, the ramp is still "steep" and I would like to know how that would reduce metal expansion noise. It looks like random noise, not a purposefully generated signal.

hokiegir1 | 15. marraskuu 2019

@derotam - I'm lazy but like numbers, so for me, the subscription is worth it. :) I don't have the patience to do what you are...but I do like to look at my various trends.

jallred | 15. marraskuu 2019

Ramp isn't steep. Goes from around 0 to 6kW in about 30 seconds.

You don't think that heating the metal slow could reduce expansion noise? You might be right, but I feel like the faster it is heated the more noise it will make.

Assuming that the heater is the dominant draw on the power (might not be), I would think that a current controlled heating element would ramp with less noise.

With PWM there would be high frequency alterations to the power and if the sampling rate is too low to see them they can start to look like noise in the time domain. Especially if there is no clock synchronization between PWM and data recording.

There is probably a ton of sampling jitter in CANbus data, so under sampled phenomena are definitely going to look noisy.

A ramped current level wouldn't be under sampled and wouldn't look as noisy.

jallred | 15. marraskuu 2019

Sorry, starting with 3rd paragraph noise is sampled data noise, not audible noise.

derotam | 15. marraskuu 2019

@hokiegir1: Yeah, I am mostly lazy because I don't have a lot of experience manipulating large data sets. My wanting the flexibility in manipulating the data overrode Tesla'Fi's subscription.

l use Excel for the most part and I don't code so I'm not using VB code, just Excel built in functions. I have learned a lot in the last few days by using my friend Google.

hokiegir1 | 15. marraskuu 2019

@derotam - I use excel almost exclusively at work (pivot tables and linked sheet lookup formulas are my friends), so if you get stuck and google isn't helpful, let me know. :) I generally work with financial data, but some of the methods to identify trends would be the same regardless of the source.

derotam | 15. marraskuu 2019

In case anyone is interested in what the raw data looks like...Below is Time and Battery Power. Time is in milliseconds.

32102 5.981508
32102
32103 6.174189
32103
32103
32115 6.13552
32115
32115 6.173545
32125
32133
32133 6.36444
32142
32142 6.17274

derotam | 15. marraskuu 2019

@hokiegir1: I'll keep that in mind. I am also looking at a program called UDPLogger(windows) that graphs everything right as you load the raw data. It has a simple interface for selecting/deselecting the fields to show. The good thing is that it automatically normalizes the time scale. This issue with UDPLogger is that I cant change what is on the x-axis from in the program.

So my biggest issue right now with Excel is how do you make a graph with whatever data on the X axis but have the scale be linear between the low and high value in the raw data? Right now I am adding in the missing time values to make that linear.

jallred | 15. marraskuu 2019

Ah. So the sampling jitter is enormous. That's good to know, we have to be sure that we don't look for trends in data that we are under sampling.

Why do you get samples that have a time of the sample but no data? And the time of sample doesn't have sufficient resolution as seen by multiple samples with the same time.

For plots to look at by human eye the only issue will be that sampling jitter will appear as noisy (y-axis) data.

Thanks for posting all of this and taking the time to acquire the data. This is like the best thing ever.

derotam | 15. marraskuu 2019

@jallred: There is other data in that set, they were just not relevant, like Battery Temp, coolant flow rates...etc. First think I usually do is compress the data in excel so that anything with the same time stamp gets put in one Row.

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