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Low batt Triggers RTH

Discussion in 'Pro/Adv Discussion' started by NinerRider, Aug 5, 2015.

  1. NinerRider

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    So I have 11 flights with my new P3P and all has gone extremely well. I have always brought the bird in as soon as battery level reaches 30%, though yesterday I decided to bring the bird close to me at the 30% mark but continue to fly in my general proximity until the battery level was closer to 20%. At 20% I get the bird directly overhead and bring it down for a perfect landing and even begin to shut the motors down when out of the blue my P3P spools up the motors and climbs for the sky in the general direction of the my take off home point. I would guess the take off and initial land spot were 40-50 feet apart. I did regain control of the bird and got it back on the ground but needless to say I was a little shaken up. After reviewing the data log, it was as I had guessed a RTH triggered by a low battery scenario. What surprises me is that it was triggered when my P3P was safely on the ground with a battery level of 17%. I think or remember reading at least one other post with very similar circumstances.
    After doing a lot of reading I still can't find a definitive number/percent of battery level at which a RTH is triggered. Also why would the bird RTH when it was on the ground granted the motors had not completely stopped?
    Thanks
     
  2. msinger

    Approved Vendor

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    The low battery level can be adjusted in the DJI Pilot/GO app. Check the app to see what it's set to. From what you're describing, it sounds like it's set to 20%.

    When your battery reaches the low battery level, a message will pop up on the DJI Pilot/GO app to warn you that your Phantom is about to return home. You have 10 seconds to click that dialog and cancel the RTH procedure before it initiates. If you do not cancel, your Phantom will do one of two things. If your Phantom is within 20m of the home point, it will auto land at its current location. If your Phantom is more than 20m from the home point, it will ascend to the RTH altitude (if not already at or above that point) -- and, then start returning home. It sounds like the latter happened in your case.
     
    acherman likes this.
  3. REBELimgs

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    I've experienced this before. I was turning off the motors when suddenly the Phantom shot straight up and tried to go home. It really shouldn't take off to return home.
     
  4. F6Rider

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    The battery level for RTH is dynamic, depending on the distance the P3 is from the registered home point. The further you are from the home point the sooner the RTH is activated. It should not have started a RTH from the ground. If you had JUST landed at the time the RTH battery level was reached within the 3 seconds it takes the P3 to register no movement then I can see it climbing to the RTH altitude, it didn't know it had landed yet. This would be one-in-a-thousand chance. You should visit Vegas.
     
  5. NinerRider

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    Thanks, so far no other occurances and the P3P has been rock solid. After reading some bad experiences I am always expecting the worst!
     
  6. GeeDee

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    Same thing happened to me...just landing with low battery and it took off on its own... when it climbed i was able to regain control but a bit unerving
     
  7. bobmyers

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    Here is another scenario-- I have been landing my PH and letting the motor idle for about a minute or two before shutting them off. Did this the last time out -- landed, after the touch down, did not kill the motors. after about 15 seconds, they reved up again and tried to take off. Happened twice on two different flights. I now shut the engines off and then restart them to go through the cool down. No issues that way. So it seems, with battery power remaining, this may be a glitch unless the motors are completely shut down after it is on the ground.
     
  8. NinerRider

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    What was the battery level at when the P3 spun up and took off?
     
  9. NinerRider

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    Yeah nothing worse than seeing that thing head towards the sky with no pilot input!