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Professional Log Analysis Help

Discussion in 'Phantom 3 Help' started by MAskinut, Sep 23, 2015.

  1. MAskinut

    Joined:
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    Location:
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    I've been doing some research on why my drone dropped from the sky very shortly after takeoff. I was in a very rural area in New Zealand and had good signal, good battery etc. It was in a full takeoff and then just turned off and dropped. The battery was still intact when I recovered it.

    I've found this site very useful (Healthydrones.com), this is a link to my flight data HealthyDrones.com - Innovative Flight Data Analysis That Matters

    I've posted a screen capture here. Dropbox - Crash.mov

    I can't seem to figure out which of the .DAT or /TXT files go with this as not of the time and date stamps seem to match up and I have about 90 flights on there. I wonder if the international dateline and an offline phone caused that.


    Any thoughts? Any idea on figuring out which txt files map to this flight?



    Thanks!
     
  2. bobmyers

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    The take off and landing battery shows 23%-- I think that may be the issue.
     
  3. MAskinut

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    [WIKI][/WIKI]

    23% is enough to fly for more than 15 seconds. That shouldn't cause a power off.
     
  4. bobmyers

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    You are asking for trouble when you take off with 23% battery and it looks like you found some-- unfortunately. A battery at that voltage is an accident looking for a place to happen, especially if you took off with it-- at that point you should be thinking land quickly not take off-- when you take off, the Phantom is draining the cells of the battery faster and if one of those cells drain down too low, the voltage required to run the motors will not be there and it will come down --- fast.
     
  5. Ing Zimmerman

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    Hi where did you get that information?
    or is it just a math calculation?
    100% = 20 minutes
    23% - force emergency landing = X
    IZ
     
  6. reboot81

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    The remaining battery in % is just an approximation. The P3, like all devices running on LiPo's estimate consumption during use and report a % while monitoring the voltage. It's an estimate calculated and not a definitive reading from the battery. This is the sole reason for running down batteries (to 8%?) – to give the smart battery an understanding of the rate it depletes.
    Therefor a battery that's reporting 23% may actually be much lower than so. And the increased temperature may also degrade it's charge in a rate that conflicts with the calculation.

    LiPo's will get damaged if run below a certain voltage. Some, I'm not sure if the P3's battery have this function, will turn off when the voltage drops below a certain level. Would be quite ironic if a smart battery will turn off mid flight to prevent battery damage…
     
    bbfpv likes this.
  7. EPT160

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    23% is much much to low to attempt take off. Check the instructions and the safe battery levels.

    You were very lucky it only lasted 15 seconds or it would have ended up in the lake!!

    And watch out for the Sipi Tau on Saturday. Those Tongans are after you:)

    Edit: Sorry I see you are from Frisco on a visit!