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My attempt to FIX to early autoland issue

Discussion in 'Phantom 2 Discussion' started by FedeVision, Sep 21, 2014.

  1. FedeVision

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    Hi all, my early autoland issue started as soon as I attached a 3 axis gimbal,
    so the P2 now weights over 1350 grs, and batteries started to heat more,
    read somewhere that batteries have an overheat protection that launch autolanding,
    so I noted that battery compartment is not well ventilated, and thought that maybe
    some ventilation might help, and it does!

    I drilled four 1/8" holes on the top, been carefull not to touch the structure, and that's it!
    Been like 20 flights since and early autoland have not shown so far,
    I guess this is not a solution for all batteries, depends on how cooked they are,
    but may be a good prevent meassure for new ones.

    Hope DJI make tests on this and maybe improve their design.

    Will post some pictures really soon.
     
  2. N017RW

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    Re: My FIX to early autoland issue

    It is to be expected that a reduction of flight time will occur when you add the weight you have.
    "You don't get something for nothing" as they say.

    So it may seem early to you after this addition.

    Looks like there needs to be much more testing to prove this thermal component before declaring it fixed as you have.

    I look forward to your continued reports.
     
  3. OI Photography

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    Re: My FIX to early autoland issue

    Very interesting! FedeVision, can you provide some numbers on voltage or time it was starting to autoland after you added the gimbal, before you added the cooling? As N017RW pointed out that'll help validate your findings...which I too am anxious to hear more about.
     
  4. pilsburypie

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    Re: My FIX to early autoland issue

    One way to prove if your ventilation holes are the cure to your issue is to now tape up those holes and fly again. If it is the case that these have given you 20 autoland free flights and not something else, you should get an autoland in a flight or 2.

    Glad your issue has rectified itself, but do this test and if it is proved that the holes are the cure you may have stumbled across something that many other might want to investigate.

    Good luck
     
  5. FedeVision

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    Re: My FIX to early autoland issue

    Correction! I made 1/4" holes.
     

    Attached Files:

  6. FedeVision

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    Re: My FIX to early autoland issue

    Didn't take notes but as long as I remember had 6-8 early autolands between 35% - 47%, red lights blinking,
    not consecutive flights, after resting a few seconds on floor relaunched without reboot, sometimes came down immediately,
    sometimes hanged until the normal 15% battery trigger.
     
  7. FedeVision

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    Re: My FIX to early autoland issue

    Nice test idea, but can't afford to risk one of my two batteries to get puffed, when vent holes are so far, preventing that.
    In this little country I don't have a RC shop on the next corner, and can't buy a lipo battery that involves an airplane travel delivery due
    recent rules, so I guess I'll skip that test, at least for now.

    GL2U2
     
  8. ianwood

    ianwood Taco Wrangler
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    Re: My FIX to early autoland issue

    Can someone link me to where this thermal auto-land logic has been demonstrated? First I've heard of it. Do we have any sort of verifiable indication that such a capability exists in the P2 battery?

    FWIW, none of my batteries are more than warm when I pull them out yet more than one suffers from early auto-land. And typical ambient temps are mid 80s here in SoCal.
     
  9. FedeVision

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    Re: My FIX to early autoland issue

    On P2V (or +) manual, battery section, battery temp sensor is stated.

    Any way, my second "healthy" battery started with eal issues over 60 discharges, maybe this mod
    helped a little or maybe not, still keeping the holes open.

    What did help some is to completely discharge the batteries, until battery cant be turned on (every 20 discharges).
     
  10. adanac

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    Re: My FIX to early autoland issue

    I have been away awhile so I didn't know that this was an issue. I have batteries that tell me they are empty when the display says they are at 60%-70%. I guess it's not just me and I didn't know that. I guess since people have already tried discharging then that won't fix the problem for me and the batteries aren't the problem?
     
  11. N017RW

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    Re: My FIX to early autoland issue

    Glad to see you back FedeVision!

    Since we last 'spoke' I had researched the possibility of a P2 internal battery temperature sensor or the like.

    Turns out you were right according to this webpage:
    http://wiki.dji.com/en/index.php/Phanto ... ht_Battery

    Which contains the following statement:
    "Charging Temperature Detection: The battery will charge only when its temperature is within 0℃~55℃. If the battery temperature is out of this range, the battery will stop charging."

    However there's no mention anywhere of this [data] being used to 'interrupt' normal flight operations or iniate a Fail-Safe/Autoland/RTH/whatever that I have found anywhere so far.

    DJI does however detail a 'hidden third low battery threshold' of 10.65 vdc which will interrupt flight operations.
     
  12. FedeVision

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    Re: My FIX to early autoland issue

    On P2 user manual:
    "Over Discharging Protection Discharging stops automatically when the battery voltage reaches 8.4V to prevent over discharging damage."
    8.4V is way under 0% (around 10V), you should test to discharge all the way down your worst battery, it won't get like brand new, but I'm pretty sure will help a lot.
    I force my P2 to fly until 7-5%, then connect a car light bulb to the battery until it doesn't turn on again, that takes like 1.5 - 2 hours.

    More info about EAL: viewtopic.php?f=19&t=17324&hilit=early+autolanding
     
  13. FedeVision

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    Re: My FIX to early autoland issue


    Thank you N017RW!
    Couldn't find where I read that interrupt thing too, thought it was on RC forum, don't know.

    Something else I read is that this batteries are like 10 C (speed of discharge),
    and the Phantoms with all the electric load (gimbal, transmitter, Gopro, ESC, motors, leds, etc) needs way more than that (20/30 C),
    that's why batteries get hot, puffed and little life. If this is true, sounds logical.
     
  14. capodrone81

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    Re: My FIX to early autoland issue


    **** you drilled right through the gps shield.. :shock:

    im not a fan of this i guess if it actually works go for it.. I'm pretty confident that if the batteries are overheating there is a bad cell and that battery should be replaced...

    I'm pretty confident since dji posted the video on their main page of the phantom flying near the erupting volcano these holes you drilled are unnecessary..

    now sand and debris and moisture can get in directly above the main board.... :idea:
     
  15. FedeVision

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    Well, made this mod like 6 month ago, so far so good, it works for keeping batts cooler with full load,
    on shiny days my batteries used to end hot, now only warm, about debris and stuff entering,
    that could happen with stock vent holes only too, good thing is main board components seems to be
    covered with a protective coat.
    I'm gonna do a test clean with moisture tissue to check how dirty it is at this point.

    Of course, if somebodie ever wants to try this, it's at your own risk, like any other mod.

    Cheers
     
  16. FedeVision

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    Hi all, got good news and some screenshots of my 2 batteries stats, got rid of early auto landings as long as I keep the quad weight under around 1320g, AND every 20 discharges drain the batteries until they can't be powered on, that is way below 0%, I got 5200 mAh capacity back on each one.

    Cheers


    Batt1Stats.png Batt1Stats2.png Batt2Stats.png
     
    #16 FedeVision, May 29, 2015
    Last edited: May 29, 2015
  17. ianwood

    ianwood Taco Wrangler
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    I think weight is the key. The batteries discharge too fast when the bird is fat.
     
  18. Fyod

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    Really good info. Thanks for digging deep into the battery issues.