Comparing SR+ to LR

Discussion in 'Model 3' started by bwilson4web, Sep 30, 2019.

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  1. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Source:

    • Both charged at the same SOC % rate - good
    • 136 mi in 20 minutes - SR+, mine show 140-150 mi
    • 181 mi in 20 minutes - LR
    The difference is I start my time AFTER the car starts charging. Their benchmark includes the ramp-up time, ~2.5 seconds.

    Bob Wilson
     
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  3. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    :D :p :D
    I see what you did there. (Or at least, I think I do!)

     
  4. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I meant 2.5 minutes, not seconds.

    When you first plug-in, the car and SuperCharger negotiate for nearly a minute before charging 'ramps up.' I suspect both are checking temperatures and other metrics. A slow ramp-up allows careful monitoring the modules to make sure there won't be an overcharge risk to one of the modules.

    My interest is in the full-speed charge and eventual ramp-down. Yes, there is an initial negotiation and ramp-up but very little charge goes into the car.

    Bob Wilson
     
  5. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    Oh, so I did not see what you did there. ;) I thought you were making a joking analogy with the controversy over using a 1-foot "rollout", or not, when testing 0-60 MPH times.

    I wouldn't think that any "negotiation" between the Supercharger and the battery pack's BMS would take that long, since it's happening at electronic speed. A data "handshake" shouldn't take more than a very few seconds. I suspect a two-minute-plus delay would have more to do with the car reconfiguring how the heat exchangers are routing the coolant fluids. In other words, a mechanical change rather than an electronic change.
     
  6. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I used the 'time-lapse' option on an iPhone to make a video recording. It include the HH:MM clock from the car which is what I use for my time base. But between the 'time-lapse' recording and coarse clock, errors can be made.

    A better approach is an independent clock with HH:MM:SS which I get with my dash cam video. Although the 24 frames/min works, it is broken up into ~3 min, large files that I have to video process. This part takes time and each file is processed individually:
    1. Load each, ~900 MB file and crop and sub-sample 24-to-1. My software requires three passes:
    • 6-to-1
    • crop to screen size (sometimes requires two passes)
    • 4-to-1
    With the recent MacOS and video application updates, I may be able to combine these steps and improve processing speed.

    SUCESS:

    I was able to reduce a ~900 MB file to ~10 MB (~2 orders of magnitude) in one pass by combining both crop and a 12-to-1 frame reduction (Nyquist limit for 1 second resolution.) Combined with a well placed dash cam, we should get more space reduction with 1 second resolution.

    I have the most recent firmware update from Sunday afternoon, 2019-32-11, and have plans to take the 1000 km challenge. I'll end it with a full, SuperCharge, session to refine my charging curve. I'm not expecting a great change as much as more precision.

    Bob Wilson
     
    Last edited: Oct 2, 2019
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