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Early Auto descend/ false low battery

Discussion in 'Phantom 2 Vision + Discussion' started by DrJoe, Jun 16, 2014.

  1. DrJoe

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    I was having a problem with one of my batteries yesterday. Even though the battery level is over 60% charged (started at full charge), I'd get a low battery alarm and the phantom would go into "auto landing mode". Not good, as I was 300 feet out filming surfing over the Atlantic ocean.

    I discharged the battery, then recharged it, same thing happened.

    I did a search on the boards, and found this topic in the Phantom 2 Vision section:
    viewtopic.php?f=19&t=17324&start=20

    I discharged my battery, as per DJI, and will do a full recharge tonight when I get home, then test it. I have a feeling I have a bad battery, but with the responses to the above posts, I'm not alone. Any P2V+ having these issues too?

    low battery discharge auto land
     
  2. cougar

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    Check the battery contacts as well
     
  3. DrJoe

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    There is no way to override that I know. I'm buying a new battery and contacting DJI support for a replacement. I did not drop or mishandle the battery in any way.
     
  4. AHill

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    Same fault, low battery warning and started to auto land at 69%. Checked it on computer with Assistant and it showed cells balanced correctly and 19 discharges. I had run battery low once per DJI recommendations. I then charged it and let it run down twice on bench with no props (no load on motors) and it showed low battery at 30%, the way it should work. Then flew twice low and nearby, both times it showed low battery and started to auto land at 49%. Previously when giving full throttle up it would momentarily alarm for low battery but would go back to correct reading within a few seconds. It appears the battery was not putting out sufficient current, maybe some flaw in battery. I have 5 batteries and this is the only one with these symptoms so I sent it back to dealer yesterday for an exchange.

    You can partially override auto land by giving it full up throttle. It will maintain altitude and very slowly gain some altitude.
     
  5. XL-Studios

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    This all sounds rather alarming. Please let us know how things develop. Did contact cleaning resolve the issue?
     
  6. erico

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    Look at the topic under phantom 2 ( non vision ) low battery warning and auto descend .. Quite a few of us are now having this problem and trying to find the solution but it is pointing to faulty batteries .



    Sent from my iPad using Tapatalk
     
  7. XL-Studios

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    Ok, been reading this topic and I find it ALARMING! Just when I was getting confident not to worry too much about fly-aways. Now this crap. The joy if flying is slowly dying on me and being replaced by worries. 9 out of 10 flights a Auto landing would mean a loss of my bird considering how I usually fly. (Over forest, water etc.)
     
  8. cougar

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    This is what I have been using on all my batteries, as well as other contacts since new.
    So far so good :)
     

    Attached Files:

  9. gecarey

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    Cougar, and anyone else using contact cleaner..... How many charge cycles do you all have on your batteries ?
     
  10. DrJoe

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    I don't think that's bad advice, but since my other battery works great, my contacts are clean, and charging seems to go without a hitch, I have to believe the problem is in the battery itself.

    To be honest, I closely inspected the battery causing the problem for bulging, etc. Guess what? No bulging, but the plastic sleeve around the middle of the battery is cracked, indicating damage. I must have bumped it, jostled it, or otherwise banged it (definitely no drop). Sensitive little buggers. DJI will not offer a replacement with this damage evident. Guess I'm out $159 plus shipping. To be safe, I will not even charge this one again (LiPo's are notorious for kabooming).
     
  11. cougar

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    Have around 20 cycles on each battery, also used a course horse brush (quite stiff only 1/4" bristles) to clean both battery contact as well as the pins/male contact in the Phantom itself.
     
  12. Wind_Shear

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    Glad it's not just me. I've been dealing with this since February when my quad almost went swimming in the Gulf of Mexico while I was filming some dolphin.

    I have four batteries, and of those I've seen this on two; one did it consistently and the other seems to do this if I run it too hard (a long ascent at full speed, for example).

    The obviously bad battery went back to DJI in LA on May 5th, and I haven't heard a thing from them since then.

    I've tried calling, have emailed a dozen times, and nothing.


    Very frustrating.

    I'll be subscribing to this thread to see what, if anything, you all come up with.
     
  13. gunslinger

    gunslinger Moderator
    Staff Member

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    Your problem is much more apt to be a battery connection problem, than a bad battery. I've had this happen on two separate occasions, and since I've begun to use contact cleaner on the spring loaded pins, located on the aircraft and the pads, located on the battery, I haven't seen the problem.

    How old is your Phantom? Do you know if the spring loaded pins have a radius on the end, or are crowned?

    Thanks...
    -slinger
     
  14. wkf94025

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    I will try contact cleaner and/or brush, but I am skeptical this is a contact issue.

    'Slinger, which contact types are better, radius or crowned?

    Kelly
     
  15. cougar

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    My take on this issue:
    Contact cleaner might not help unless they are new, better use Deoxit to remove/resurface any built up oxidation. That would be very important in humid climate/close to any salt water. Use a stiff brush first and then clean/protect with Deoxit.
     
  16. Double-D

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    Early battery warning and auto land problem

    I posted this in the this running thread viewtopic.php?f=19&t=17324&p=167370#p167370 but though I would post here also as I fly a Vision+.

    Well you can add me to the list.
    Only had my Vision+ for about a month. Today I was totally surprised when I saw the low battery warning on the app at 53%. It flickered on and off a few times before staying on at 51%. It was over water so headed straight for home. Not sure when auto land initiated as I noticed the percentage dropping strangely rapidly but was around 40% which it fell to very fast. By the time I landed it was on 3%. I turned it off immediately rushed inside to look at the battery status on the assistant software and it read 1%.

    Vision+
    Firmware - 3.04
    Warning levels - 30%/15% default
    Discharged - 28 times
    Battery life - 91%
    Auto land initiated - 40%
    Flight condition - slow and calm

    Later I charged it up to 62% and flew again.
    Low battery warning @ 33%
    Auto land initiated @ 29%
    Power cycled and lifted off and flew for about 1 min then auto landed again.

    As per the Dji guidelines I did a thorough discharge at 20 cycles.
    I do charge my batteries 100% straight away after flight (after reading the posts I'm not sure if that's a Good or bad thing) but I use them almost every day only missing the odd day due to weather.
    currently charging this battery from 29% and will test again tomorrow.
     
  17. Double-D

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    Re: Early battery warning and auto land problem

    It's more than a pain in the ***. It's bloody worrying!

    Sounds like we were both very lucky to not end up in the drink.

    I had the normal auto land controls e.g. all sticks but only able to maintain height with maybe a little altitude. If I'd had no sticks it would have gone down for sure as I was only a few meters above the water. Lucky it didn't happen on the first battery as I was over 500m away over trees.
    I'd only run this suspect battery a few hours beforehand and all was fine.

    The batteries being so expensive is even more of a kick in the guts.
     
  18. Double-D

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    Re: Early battery warning and auto land problem


    Have you had problems with these batteries before?

    I'm going to try mine again tomorrow using different charge cycle percentages and see what happens.
    Interesting they know about the problem.
    Think I'll be calling my dealer as well. I took a screen shot off my battery status also.
     
  19. wkf94025

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    Several comments here:
    1) Enough of us are experiencing premature auto-landing ("PMAL" ?) that we're clearly not imagining it, and shouldn't have much trouble gathering ample evidence that DJI and its dealers cannot ignore.
    2) At best it's cutting deeply into a limited shooting session, and a nagging worry as the flight progresses -- how much real fuel is left in the tank?? At worst, it's a complete loss of aircraft and camera, with possible liability to civilians and property owners below.
    3) This shortcoming is well below forecasted battery life by DJI, and ironic in light of their battery pricing and their recent press release attacking other battery manufacturers, and hailing theirs as the golden standard.
    4) Getting smoking gun evidence is going to be very straightforward. If you can provide a video with DVR'd iOSD of the flight, and your narrative of the flight and your control inputs as you near pre-mature auto-landing. Ideally (or instead of DVR) have a second camera over your shoulder showing stick inputs, and iOSD display in real time. Grab a screen shot from Assistant battery page and firmware page with the battery fully charged, and from the battery page again post flight, especially if you can land as soon as PMAL begins.

    Kelly
     
  20. nhoover

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    One of my older P2V batteries has this problem sometimes. It was only bad once, flying out over a lake 800' away and it suddenly wanted to land. Luckily I had enough height to notice and give it full throttle and fly back. This particular battery usually doesn't cause auto-landing, but will give a low battery alarm at 40-50% when doing a full power ascent or forward run. Problems started only after more than 40 cycles and my other 3 batteries don't have this problem. I always do the recommend discharge down to 8% every 20th cycle on each battery. Will try some contact cleaner, but for now I've been using this one ok, but not trying any aggressive flying with it.