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Gen 3 12V voltage from door opening to Ready

Discussion in 'Gen 3 Prius Technical Discussion' started by qettyz, Apr 29, 2019.

  1. qettyz

    qettyz Active Member

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    This is again my "data is beautiful"-stuff, maybe not so useful.
    I have 2014 Toyta Auris (known as Corolla in AU) Hybrid. It has same Gen3 hybrid system as Prius.
    Today i logged whole startup procedure with Picoscope 4227.

    Note: car has ~2 years old OEM 12V battery and there has been no issues with it.
    Car also has powered side mirrors what were rotated open before logging starts(i went inside from passenger door to open hood).
    Voltage was monitored from engine bay fusebox, ground was from inverter bracket.

    Screenshot with few points.
    After pressing startup button there is one quite deep peak below 8v what supriced me.
    Toyota Auris Hybrid start.jpg
    Attached PDF-file is same as screenshot. Zip file contains psdata-file what was saved from free Picoscope software what can be used to view saved file without scope.
     

    Attached Files:

  2. Pluggo

    Pluggo Senior Member

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    Very nice data. Auris is Corrola in the U.S. also.
     
  3. bisco

    bisco cookie crumbler

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    the voltage needs refining to 'tenths'.
     
  4. qettyz

    qettyz Active Member

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    Data can be zoomed and diagnosed with that software. There is quite much data to zoom and millivoltages to see ;)

    Edit:
    For example drop at ~14s is to 7.022V
    7022v.jpg
     
    #4 qettyz, Apr 29, 2019
    Last edited: Apr 29, 2019
  5. ChapmanF

    ChapmanF Senior Member

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    Very nice. Do you have a record of what was happening at different time points? I assume that 2.3s was about when the driver door was opened. There's about 10 seconds of dropped voltage from there to 13s, where it recovers. Were you waiting for the brake pump for that period? When was the power button pushed?

    How many input channels does your PicoScope have?

    It might be interesting to keep one on the front panel where you took this, and another channel on the 12 volt battery itself (right at the lead posts). If there are additional inputs, they could monitor the various power distribution relays, ACC, IG1, IG2, ABS, EMPS, etc.
     
  6. qettyz

    qettyz Active Member

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    @ChapmanF yes i was waiting for brake pump and started car when it stopped. Those are marked in the image.

    Picoscope has two channels, indeed would be interesting to scope out relays.
    I was thinking to read from 12v battery also to see if there is also deep spikes. And if there is, umh what if i add 1F car audio capacitor, could it level those out (this i am not sure if going to try because i dont have one).
     
    #6 qettyz, Apr 30, 2019
    Last edited: Apr 30, 2019
  7. Maarten28

    Maarten28 Active Member

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    Not to be picky, but could you post the same data with a more sensible scale? 0-16V would be a lot better, but 8-16V would also fit.
    I mean, the voltage will never be negative, not even while driving backwards. ;)
     
  8. Grit

    Grit Senior Member

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    1 farad won’t do much, caps provide power for instantaneous amperage draw but may not level out voltage stability. I do see your logic and it does make sense
     
    Raytheeagle likes this.
  9. qettyz

    qettyz Active Member

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    @Grit That deep drop to 7v after power button switch may be because measurement was from fusebox.
    But, if same drop is at battery poles, then i would expect 1F cap provide instant amps to prevent such short voltage drop. Sure it would not make anything better or different, car works fine with that. This is just me being interested :D

    Some time ago i saw youtube video showing scope readout from regular car start crank and claiming that if voltage drops below 8v, then you need new battery. Our cars have small battery and its just booting computers and activating relays. Somehow i wont think seeing that 7v reading from battery poles or do not know what to think if i get same data.

    That drop to 7v was very short. Measurement was 1 million reads/sec and it is one measurement point what is so low. So it can be anything from handheld reading from fusebox to poor gnd etc.

    I do test from batterypoles someday and post same data to compare.
     
  10. qettyz

    qettyz Active Member

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    So, i measured today directly from battery. Result was about the above but totally without any spikes.
    Managed to loose scope buffer and it was gone. Didnt measure another one, because there would not be any brake caliber stuff etc.
    ...another day....another....
     
  11. qettyz

    qettyz Active Member

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    Finally, UPDATE

    This is now measured directly from the battery poles.
    - Car has been sitting ~8 hours.
    - Before measuring side mirrors are folded out when unlocked and trunk light has been on ~1min.

    Lowest measurement is ~11,2V when brake is pressed. Nice flat line compared to fusebox reading.

    Auris Hybrid 2014.jpg
    scope_data.jpg
    Upper i wroted that these measurements are million/sec, uh no. It's about 200k/s.

    Now if i just had an amp measurement stuff for picoscope, it would be nice to get amp reading also from that startup sequence.

    Attached is PDF print from Picoscope software and in the zip-file there is raw psdata-file what can be opened in Picoscope software.
     

    Attached Files:

    CR94 likes this.