Model 3

Temps, Precondition, Regen data with GRAPHS

edited January 16 in Model 3
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.
«13456710

Comments

  • edited November -1
    Sweet. Thanks!
  • edited November -1
    How refreshing. Actual data.
  • edited November 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
  • edited November 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.
  • edited November -1
    Ah the sweet smell of facts . . . thanks.
  • edited November 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.
  • edited November 2019
    Since I have been collecting data, I think I have gotten my stator up in the 50's.
  • edited November 2019
    updated OP OP for quick and dirty info on 32 mile 51 minute commute home.
  • edited November 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.
  • edited November 2019
    Nice, thanks!
  • edited November 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?
  • edited November -1
    Not exactly sure the exact position but perhaps there is a sensor just inside the pack where the coolant enters the pack.
  • edited November 2019
    Maybe it is listed in the parts catalog....I'll have to try and look.
  • edited November -1
    And sorry I shouldn’t have said “system;” I realize it’s closed loop. Meant where it enters the area of intended heat transfer.
  • edited November 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!
  • edited November 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.
  • edited November 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_progressive,q_80,w_800/jvrtfet4rkx30b211k35.png
  • edited November -1
    @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.
  • edited November 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.
  • edited November -1
    Updated OP, added Battery Preconditioning(not moving) vs driving with no BP
  • edited November 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).
  • edited November -1
    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.
  • edited November -1
    Your ambient temps are super low. Your conclusions about preconditioning with normal driving may be different on warm days.
  • edited November 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.
  • edited November 2019
    The driving vs battery preconditioning statement was flat out wrong.
Sign In or Register to comment.