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Critical low voltage with 44% battery remaining

Discussion in 'Pro/Adv Discussion' started by Reuben, Nov 22, 2015.

  1. Reuben

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    So before any one jumps on to me I have read loads about this situation on here and yes I know I should have fully charged before flight. So this is what happened.

    The weather here has been awful for the last few weeks therefore I haven't flown my p3p for about 3-4weeks. Today was my last day chance to do a quick test flight before taking my bird with my abroad. So put in a battery which had about 50% charge left on it since I last used it 4 weeks ago. Went to the back garden and attempted to do a quick hover at about 3-4m height. I have read loads of warnings over here not to fly with a battery which has not been used for a while unless recharged. So was extremely cautious. Long story short 2-4mins into the flight I was at 44% batt 3.7v and I got a red critical low voltage warning. Aircraft landing! and it started coming down on my lawn so issue. My bird is safe ;)

    My question really is. Is there any additional precaution I need to take for my next flight apart from charging it of course.
     
  2. msinger

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    I know we already beat this to dead on Facebook. You should never start a flight with a battery that is nearly depleted. And, by depleted, I'm referring to about 30% charge remaining. Also, you should monitor the battery voltage thoughout your flight. More information can be found about that here:

    HOW TO: Monitor battery voltage to watch for signs of failure | DJI Phantom Forum

    The auto landing is a safety measure that DJI put in place to help prevent Phantoms from dropping out of the sky. It looks like it saved your Phantom... this time.
     
  3. Reed L

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    The battery depletes itself in a max of 10 days, so you went 4 weeks and even though it showed 50% there was nothing. All you can do is charge it before using it.
     
  4. msinger

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    The batteries will only auto discharge down to about 60-65%.
     
  5. Mako79

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    Happened to me just 2 days ago.
    Had 50% on a battery I haven't used for a week. I always top off before flight. But something interesting popped up and I quickly got airborne. At about 500m out and 45%, I got "AIRCRAFT LANDING" warning. In order to stop the force landing, I switch from P to F and back to P. This cancelled the landing.
     
  6. GoofyBird

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    Ok here is what's happening, you leave the battery unused and it auto discharges to 60-65%, you then put it in the bird and start flying, now critically low voltage comes up and the bird starts to auto land. You can override the landing by either switching out of GPS or just engage RTH and then disengage it. The bird has the 50% of battery life you see but for some reason isn't registering the correct voltage. To avoid this, fully charge your battery if it has started into the auto discharge cycle before you take off.
     
  7. Wacker2611

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    If you'd read up on the whys and wherefores of flying with a depleted battery that's been left anything over a day, I can't understand why you took off anyway? Surely you're just asking for trouble?
     
    dirtybum likes this.
  8. Reuben

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    was doing just a quick test flight before taking it abroad. The reason I didnt take it high is because i knew that this might happen. So lucky for me I spend a lot of time here and was prepared for this situation ;)
     
  9. alokbhargava

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    Only precaution you need to take us charge the battery to full before flying.
     
  10. Helijoc

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    I have read that you not only top off the battery but actually turn it on before plugging it into the charger.
     
  11. Oso

    Oso

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    When I saw your thread title, I was thinking to myself, "Oh no, they are going to crucify him." With that in mind, I read your first sentence and it made me laugh. Cheers!
     
    #11 Oso, Dec 19, 2015
    Last edited: Dec 19, 2015
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  12. kirk2579

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    that is how to really top it off.. turn on and then charge . it will go to full that way

    if it is at 85% and you plug charger in it will not charge , it will consider it full. to turn on first corrects that.
     
  13. alokbhargava

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    Some one has conducted tests and proved that it's a defect in battery FW that is causing these surprises.
     
  14. John Locke

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    Yes, that's what I've read elsewhere. DJI knows about this anomaly and has reproduced it. The same problem has been experienced in Inspire craft also. I read that DJI has already released new firmware for Inspire batteries but it hasn't fix it 100%, only partially, whatever that means. I would assume they are still working on fixing the battery firmware.

    In my opinion, and I believe DJI's too, a craft should not fall out of the sky as some have reported due to sudden unexpected battery failure with little to no warning. It's logical the controller should give a low battery warning at least 2 to 3min before it goes into auto-land. No way should the motors stop and the craft fall from the sky, that's just wrong, definitely flawed. Anyone that thinks that is OK is way out in left field, IMHO. The fact that most forum members know about this anomaly makes it clear, right now it's absolutely imperative to charge to 100% before all flights, which I do anyway, but annoyed that's it's so critical, apparently. However owners that aren't part of this forum may not realize there is a subtle firmware flaw that DJI is working on, and as a result lose their craft in water, or other catastrophic results, virtually not knowing what happened, possibly thinking it got attacked by a bird, etc.

    I'm just wondering, does this occur by flying a battery only 80% charged? 75%? 65%. I can see very easily some guy trying out various lens ND filters, going up for 4 min, taking some shots, coming down and changing a filter, going up again for 4min, coming down, up, down, etc. Do we really know that wouldn't trigger this anomaly? Are we absolutely sure the battery must be removed and re-inserted at partial charge to run this risk? It's unclear to me, but I know I won't be doing anything like that for a while, until it's fixed.

    The other question I have, do we really think DJI will announce this fix, explaining what it fixes, or will they just introduce new battery firmware with no information (which has been known to happen)?

    These smart batteries need some schooling, because today it appears they act moronic in certain circumstances.
     
    #14 John Locke, Dec 19, 2015
    Last edited: Dec 19, 2015
  15. alokbhargava

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    It's very unfortunate that DJI and their reps keep denying issues unless proven by someone. So many have lost their birds for no fault of them. Good that we found that charging to 100% before flying is safe and a temporary solution. Thanks to the forum.

    Off topic: We have many other issues like stress cracking and major vibrations. DJI should look into these issues too.
     
  16. flyNfrank

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    I skimmed over 15 post above this one and did not see one person advise you to do what should be critical at this stage. :(

    :oops: Oops! I just realized I'm too far ahead of this situation. **** it! I can't talk about it. It's ready and will be available any day now.
     
  17. sifu128

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    I guess you were right, a new firmware just came out with no explanation other than -> In cold environments, propulsion output is automatically adjusted based on battery temperature and cell voltage. Horizontal and vertical speed is also decreased to avoid triggering battery protection.
     
  18. SolidP

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    According to my app I've got the latest FW but the problem as described happened to me today. I did not know that a "top up" is always needed and took off. Guess I had about 65% battery and about 20 seconds in to the flight this warning came up. I paniced and hit "down". Released it and realised it kept going down. Managed to grab it so it's alright but is the battery okay and can I fly it again?!?! It would be nice to somehow know what caused it. Was it just because it wasn't "topped up" or was it the cold weather (+1C). Anyway to find out?

    Have been getting all sorts of warning from my drone and as said before I'm loosing fate....
     
  19. msinger

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    Upload your DJI GO log here and post the link back here.
     
  20. GoofyBird

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    Solid,
    just read your issue and your problem wasn't due to cold weather, it was because the battery had already gone into auto-discharge mode and you took off without charging it back up. 65% is the level the battery will read when it has auto discharged but for some reason it will go into critical battery mode if you try to fly with out charging. I have been able to override the auto land when this happened to me, but I was perhaps just lucky. Bottom line here is if the battery doesn't show all 4 lights, CHARGE IT.
     
    WetDog and SolidP like this.