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Temps, Precondition, Regen data with GRAPHS

Temps, Precondition, Regen data with GRAPHS

NEW READER Note: The comments in this thread don't matter as they either are irrelevant to this data, or the discussion led me to add, delete, or otherwise adjust my statements for accuracy.

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.

*At 55F outside Temp, the maintenance draw from the cabin heater to maintain an 80F Auto set point is approximately 3kW

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.

Misc random Single data points:
At 6C outside temp, 60-65mph for ~15min, Stator temp DROPS to 30C from 35C.

jallred | 15 novembre 2019

The other timestamps that are identical included other data from other sensors?

I understand.

If you took each sample time and subtracted the previous sample time you would see how much jitter there is in sampling time. If data came every 1 msec, then the difference would always be 1. In data above the sample time differences are 1, 12, 0, 18, and 9. Lots of jitter. It is what it is. No worries.

derotam | 15 novembre 2019

Yes lots of jitter, but the theory was that the noise was caused by jitter. After doing a quick jitter analysis, the jitter is "even" throughout the dataset. The graph shows the "noise" reducing at a certain point, but there is no difference in the jitter distribution throughout the entire dataset. So I don't know why it is noisy and then levels out, but in my opinion it is not because of the jitter profile.

majassow | 15 novembre 2019

Detoram: sorry I'm late to the data party. Re: 1M row limit in Excel: have you tried the powerpivot add-in? Comes with all the recent versions, and can handle 10M rows easily, more I'd you have 64b Office.
Really makes plowing through data this size much simpler and faster.

jallred | 15 novembre 2019

Thanks for checking that. So that rules out that it was a sampling jitter problem.

I'm sticking with my idea that they ramp up the heater somehow and while ramping it shows up noisy. But when it hits steady state final "all on" the noise goes away.

Plus the "noise" actually doesn't look like noise. 1) It gets larger as the actual power gets larger. 2) It's hard to tell without zooming in, but it looks periodic to me, not random.

Typically, signal to noise ratio gets better as the signal gets larger because the noise stays the same amplitude.
In this case the SNR is staying the same because the noise is proportional to the signal.

What does the power output look like for the first minute of a car starting up, but without letting the heater start?
That baseline would help us to see if any other component plays a role in the power.

jallred | 15 novembre 2019

The same noise is there for the super quick ramp down of the heater at the end of the graph.

jallred | 15 novembre 2019

On your 10 min of BP while not in motion graph, did you turn BP off at the end of the graph? Or was it starting to cycle? I know it is just rear motor, but it never gets up to the 7kW that someone else has reported. Looks like it is more like the 4kW we know and love.

majassow | 15 novembre 2019

Detoram: re: missing values. In powerpivot you can create a time series table, create a relationship between your time series table and your data table, then use the time series as your x axis.

derotam | 15 novembre 2019

@jallred: define startup...batt power is around .5kW when you get in the car...even stepping on the brake doesn't do really anything to that.

derotam | 15 novembre 2019

@majassow: I will have to look in to that, thanks

derotam | 15 novembre 2019

@jallred: yes I turned off the heater at the end. It leveled out at about 7kW in the graph.

derotam | 15 novembre 2019

@jallred: just got in my car... .25kW, stepped on the brake and it went to .40kW.

jallred | 15 novembre 2019

So in the cabin heat data set all of the power is going to the cabin heater (except for .4kW). They don't just turn the heater on full, they ramp it up over about a minute. And while they are ramping it the power is somewhat noisy and the noise level is proportional to the actual power. When they get to full power (6kW) the noise goes away. When the heater gets turned off, it ramps down (but within a couple seconds) and it has similar noise during those couple seconds.

During preconditioning, the stators are being heated and it consumes about 4kW on the rear motor.

When the car is moving and preconditioning, heat is directed from the motor to the battery, but the motor seems to be in normal driving mode. No additional power is used for preconditioning while driving. At least according to the data you have collected.

derotam | 15 novembre 2019

Looks like you got it...all the way till you got to "No additional power is used for preconditioning while driving."

The jury is still out on that. It's a hard thing to test but I do know from looking at the data live that it does add a heating power waveform to the motor at low speeds. I would need a dyno to be able to get a good answer.

Bighorn | 15 novembre 2019

My empiric test suggested about 115 Wh/m were attributable to battery heating in motion. The battery heating will go off at about 32C. The Reddit experiment showed it go off after a couple kWh and a temperature rise slope of 1C per 132 Wh, from memory.

jallred | 15 novembre 2019

Yes. I think you are right under most conditions. Although there may be some conditions where it is happen with heat generated by normal driving profile. Bottom line is that worst case power is when stationary. It only gets lower when moving.

derotam | 16 novembre 2019

Yes, now on the AWD while driving you will get heating pwr to the front motor which isn't used a lot in normal driving conditions.

WW_spb | 16 novembre 2019

Very interesting. Strange Mr F is absent. I guess he is not interested in energy consumption anymore and his winter strategy. LoL.

Fuzzball | 16 novembre 2019

Mr F is a very wide net :)

derotam | 18 novembre 2019

Added Hold mode vs Roll mode Regen graph

jallred | 18 novembre 2019

Nice new data. Thanks again for your efforts.

derotam | 18 novembre 2019

No problem, I love playing with it and I was wanting to get hard data to counter some of the crap info some people have tried to post.

derotam | 7 gennaio 2020

Added a new data point IRT cabin heater.

ADinM3 | 9 gennaio 2020

@derotam, great post, I don't know how I missed this earlier. This will take longer than my lunch break to digest.

Any case, just to understand the setup better...

How far away was the SC you were routing to and what charge rate does it support?

I've assumed the in route battery warming takes into account distance to avoid premature warming. Also, I would assume warming would be a function of the max charge rate of the SC you are targeting as charging at higher rates would require a warmer battery.

Do you notice anything along either of these lines?

derotam | 9 gennaio 2020

@ADinM3: The supercharger I was using was approx 15 miles away. Supercharger charge capability is mostly irrelevant, unless the battery target temp follows a curve based on SC capability. I think that is a stretch right now and there is no indication that that is true. I don't think there is a target temp currently enumerated in the ScanMyTesla app and I don't feel like sitting around and wasting the power to find where preconditioning turns off.

As far as distance, I really think there is just going to be a max time limit for when preconditioning would start. IT would not be good for the public to see preconditioning turn on right at the beginning of a 200 mile leg to the next supercharger. That is just my opinion though.

Yeah there could be a curve fit on the target temp based on supercharger capability but that would be a little difficult to test as there isn't currently a battery target temp enumerated in the ScanMyTesla app.

majassow | 9 gennaio 2020

@derotam: Nice data! Thanks for posting this.

I particularly like the Regen vs. Time with speed data as you can use that to estimate the regen efficiency by integrating kW over time -- area under the green curve -- and compare to delta Ke of the vehicle going from 70mph to 0.

My measurement of the Regen energy from this graph is 241Wh -- interestingly, about 1 mile of range.

Assuming your LR RWD had 300lbs of driver + cargo, the kinetic energy of the car traveling at 70mph is 915.6kJ or 254Wh.

Which results in a regen efficiency of 95%. This matches my empirical calculations I posted about a year ago.

If you have a better estimate of the total cargo + driver weight, I can refine that number. Each 100lbs represents a 3% change in the efficiency calculation.

derotam | 9 gennaio 2020

@majassow: Driver 150lb, cargo less than 30lbs.

majassow | 9 gennaio 2020

Based on posted curb weights for LR RWD of 3805-3814 lbs, that makes the regen efficiency 98%.
Which is incredible.
In both meanings of the word :-).

There is some error due to my measurement of the area under the curve from a posted photo... Since you have the raw data, any chance you can calculate that directly from the data?

ADinM3 | 9 gennaio 2020

@majassow, 3% efficiency loss per hundred pounds, hmm, guess I will never be as efficient as derotam. Lol

@derotam, I was thinking exactly the same regarding SC charge rate and distance. I mainly asked because I live about 25 minutes from a SC and the only time I tried pre-warming I didn't notice any improvement in Regen so either the distance matters which I expected or I need to repeat the test a few more times.

majassow | 9 gennaio 2020

ADinM3: you misunderstand: you don't lose efficiency for an increase in mass. It just changes the reference for the data that derotam collected. You'll see exactly the same regen efficiency, but if your mass is higher, you'd get longer regen than derotam.

ADinM3 | 9 gennaio 2020

@majassow, Yes, my joke was poorly worded.

derotam | 16 gennaio 2020

Hey Bighorn, was just thinking about regen efficiency and had the thought of comparing energy used for a 0-70mph run vs regen from 70-0. I looked back at my data where I did a 70-0 regen and then immediately a 0-70 acceleration. Very preliminarily here I got an 80% return from the regen. Does that sound reasonable? I am going to look at the data more closely to see if I am missing anything but I wanted to toss a first pass at you to see what you thought.

0-69.5mph acceleration used 0.302kWh of energy, and 69.5-0 regen captured 0.243kWh.

Method of analysis using captured OBDII CANbus data
Divided each Motor Power value by 3,600,000 to get kWh per millisecond, then multiplied by the number of ms from last Motor Power data point. Then just added it all up.

andy.connor.e | 16 gennaio 2020

I mean, even not driving the car that sounds reasonable because the motors were not responsible for 100% of the vehicle slowing down.

FISHEV | 16 gennaio 2020

"I've assumed the in route battery warming takes into account distance to avoid premature warming."

Last 10 miles seem to be the most important. Yesterday when the cold weather ran the car down to 6 miles of range and I had to use the new electrify America fast charger that went in 2 miles from work (150kW max, 50kW Chademo for non-CCS Tesla owners). On the way, 18 miles, to the SC, three hours later, the Preconditioning didn't come on until 8 miles out. Typically when I go from home to SC, 10 miles, Preconditioning starts immediately. Makes sense as that is colder battery, having sat overnight for 10 hours.

This was in 32F in the AM and 40F by 2PM.

When I got there I could only charge to 90kW from the charger. I wonder due to the low state of the battery if Preconditioning was reduced and battery temp was low enough to restrict charging from the 140kW that the 150kW SC's should be providing. Only 3/8 of us charging but two chargers were down, one lights out, tape around it, nacelle broken and one just put out 3kW (three of us tried it and that's all it did) so no reason for low power other than SC malfunction on battery still too cold for 140kW as car was preserving range to get to SC.

Range after EA charge and cooling off was 7%/22 miles battery/Rated but Projected, based the cold last 30 miles of driving, was 18 miles with SC 18 miles away.

In both cases, at 10 miles away, that's about 15 minutes. Be interesting to see how consistently that is over the Winter.

M-A-B-MCMLXXX | 16 gennaio 2020

The methodology seems reasonable, but it has a couple of assumptions:
1) that power is constant across each time internal, and
2) that all kinetic energy converted this way is captured in the batteries.

2 is the least likely, there will be losses from heating. However they’re potentially minimal.

My $.02

M-A-B-MCMLXXX | 16 gennaio 2020

@thefish, January 16:
“Last 10 miles seem to be the most important. Yesterday when the cold weather ran the car down to ***6 miles*** of range and I had to use the new electrify America fast charger that went in 2 miles from work ”

@thefish, January 15 (i.e., yesterday)
“After seeing ***“3 miles”*** range left on the car at noon in the parking lot, I zipped over to the new Electrify America fast charger just 2 miles from the shop.”

@Abraham Lincoln
“No man has a good enough memory to be a successful liar"

andy.connor.e | 16 gennaio 2020

He changes his story because the first comment about 3 miles of range was on the previous page, and whenever the comments move to a new page everyone forgets what was said previously.

Thank you @MAB for pointing this out again. Maybe people will pick up on that FISH is not a valid individual to respond to.

derotam | 16 gennaio 2020

@MAB1980: Yes, I agree about the time aspect The time between data points ranged from 1-206ms. There were only 3 intervals >100ms. Average interval was 14.59ms across 436 data points.

That was for the 0-69.5 run. 70-0 regen was 1726 data points, 11.47ms average interval, 7 intervals >100ms.

Other data to note is the motor power was indicated to a 0.5kW accuracy.

derotam | 16 gennaio 2020

Hey Fish, since you are saving all that money by not being able to install an outlet for charging your car at your house, why don't you go and spend ~$150 for an OBDII adapter, wiring harness, and ScanMyTesla APP, and get some REAL data!

FISHEV | 16 gennaio 2020

As you gain more experience with the car, you'll find the Tesla changes the Range rating as it warms up. The 3 miles it shows on the app became 6 then 8 miles as I drove the 2 miles to the EA chargers. It will even go up as ambient goes up. Battery was at 7% when I started charging which by Rated Range is 20 miles left (well 20 miles due to battery degradation after 16,000 miles) and Projected, taking into account the cold, wet, over 60 mph driving was around 8 miles. That 7% battery showed 3 miles, 6 miles, 8 miles as the car goes from Snowfake cold to warm. When I looked at 10A, sitting for four hours, it was 3 miles. Eek!!!. When I got in at Noon it was 6 miles. When I got to charger it was 8 miles.

I doubt most owners with home charging see these numbers or situations while those of use without see it all the time. You get a much better idea of how EV's work in the real world if you depend on public charging as we depending on public fueling on ICE cars.

teslamazing | 16 gennaio 2020

If you had simply just left 15-20 min before work to a SC on your 60 min drive to work, you would’ve had almost half a tank. The drive itself would’ve warmed the battery fully to achieve high kW charging without the use of pre-conditioning since you fear that a lot (bonus)

Buuuuut instead you spent hellla time charging at two different chargers.

Too funny.

M-A-B-MCMLXXX | 16 gennaio 2020

@fish January 16
“ When I looked at 10A, sitting for four hours, it was 3 miles. Eek!!!. When I got in at Noon it was 6 miles. ”

@fish January 15
“ After seeing “3 miles” range left on the car *at noon*”

Shall we continue?

teslamazing | 16 gennaio 2020

Lolol the lies are creeping up.

Too funny.

FISHEV | 16 gennaio 2020

"Shall we continue?"

You bet...but links would be good vs. chopped up "recovered memories". The range does move with the temp even if the car is parked and not moving.

What was shocking was that car had over 20 miles of range when I pulled into the lot in the AM and 3 when I looked before lunch to see how the cold was affecting the range. No passive loads like heat or Summon or Sentry on yet just the change in the battery temp dropped the range from making it to SC to not and needing a charge to get to the charge.

teslamazing | 16 gennaio 2020

@fishy
If you had simply just left 15-20 min before work to a SC on your 60 min drive to work, you would’ve had almost half a tank. The drive itself would’ve warmed the battery fully to achieve high kW charging without the use of pre-conditioning since you fear that a lot (bonus)

Buuuuut instead you spent hellla time charging at two different chargers.

Too funny.

Magic 8 Ball | 16 gennaio 2020

Amazing that someone that claims to know a lot about EV's finds normal operation shocking.

andy.connor.e | 16 gennaio 2020

The inconsistency in FISH's story with his excuses are inexcusable. Especially considering his posts are here in this thread for everyone to view at any moment, there is nothing to say. He is just saying whatever is convenient to what he is responding to. There is no consistency.

FISHEV = Robotic Response Generator V2.0

FISHEV | 16 gennaio 2020

Thought I had enough to not need charge night before to get to work and make SC after work. The 20 miles left when I got to work should have done it. It actually might have made the 18 miles to the SC even though Rated and Projected Range said it would not.

Had all the Tesla issues that day, frozen out of car in AM, actual range getting whacked bad by the cold. It was the parking lot "loss" that did me in.

Bighorn | 16 gennaio 2020

Flagging helps him get away with his lies because the proof goes poof

Magic 8 Ball | 16 gennaio 2020

Tesla is a thinking person's vehicle, not a vehicle for someone with fish brain.

WW_spb | 16 gennaio 2020

Yo, Fish is broken record!

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