Welcome to InspirePilots.com

Join the leading DJI Inspire community for free!

Severe battery % loss during flight

Discussion in 'Inspire 1 Discussion' started by TAMedia, Feb 26, 2015.

  1. TAMedia

    Joined:
    Oct 6, 2014
    Messages:
    7
    Likes Received:
    0
    Location:
    Toledo, Ohio
    Hello, last night I decided to attempt some night pictures. It was 14 degrees, fairly calm wild conditions, and i was 9 mixtures into the flight. Everything was working correctly and i was getting some great pics until the battery got to 41%. It suddenly went from 41% to 8% in 2 seconds, the landing gear started to lower and my heart rate jumped, lol. I was over 200 ft high and a few hundred feet out. I was able to get it back and land it, so theres nothing happened to the bird, but would just flying in the cold create that dramatic % drop?

     
  2. Method007

    Joined:
    Jan 10, 2015
    Messages:
    44
    Likes Received:
    20
    Yes, it can. Lipo's are quite sensitive to temperature.
     
  3. Funnone

    Joined:
    Jan 23, 2014
    Messages:
    126
    Likes Received:
    29
    Location:
    Toledo,Oho
    yeah I had the same thing happened about a month ago was at 34% decided to come in to land, about 6 feet off the ground low battery warning ⚠ 30% no big deal, 3 seconds later, critical battery warning 5%. landed without incident temperature outside around 29 degrees with a 8 mph wind.
    Like meth said “Lipo's are quite sensitive to temperature.”
    I see your in toledo also.
     
    #3 Funnone, Feb 26, 2015
    Last edited: Feb 26, 2015
  4. TAMedia

    Joined:
    Oct 6, 2014
    Messages:
    7
    Likes Received:
    0
    Location:
    Toledo, Ohio
    Ya I knew they were sensitive to cold, but I've never had a % drop like that before, pretty crazy. Thx for the replies guys
     
  5. catware

    Joined:
    Oct 19, 2014
    Messages:
    90
    Likes Received:
    64
    I had a similar drop with one of my Phantom 2 batteries, from 25% to 4% in a couple seconds, but this was in 75 deg weather. The next flight with this battery, when it reached 85% (from a full charge) it dropped down to 10% in just a few seconds. I determined it was a faulty battery and I had it replaced under warranty. The battery had 27 flights on it at the time.

    So maybe it's related to the cold, but I'm surprised that it dropped so quickly nonetheless.

    This is from an RC battery manufacturer's specs, "Lipo batteries will experience a 30% temporary decrease in capacity at temperatures below 32 deg F. Flying in extreme cold weather should be done with great care. Never expose them to temp. below -4 deg F."
     
  6. jon b

    Joined:
    Jan 8, 2015
    Messages:
    394
    Likes Received:
    129
    Location:
    Chicago
    Absolutely makes sense. The chemistry in Lipo batts are pretty sensitive to cold, especially if they are directly exposed. Phantoms actually fare better since their small lipos ride inside but still, when the temps drop down you have to be very careful. I took an S800 out the other day and saw the same kind of thing. A 10K MAH batt couldn't muster better than a few minutes in the air.

    Heard talk of battery warmers on this forum and scoffed but maybe it's worth the draw to insulate the cells?

    My fingers get too cold to get into much winter flying anyway:)
     
  7. RossF

    Joined:
    Jan 23, 2015
    Messages:
    44
    Likes Received:
    10
    Has this happened before with the same batteries at the same temps? I have been flying a lot in 10 - 20 degrees fahrenheit weather in Chicago. Sometimes over a lake, I bring my inspire back around 30% always but have never experienced a battery drop. I was thinking I "trust"it now but I feel a little nervous again after reading this.
     
  8. jon b

    Joined:
    Jan 8, 2015
    Messages:
    394
    Likes Received:
    129
    Location:
    Chicago
    What I was posting was with my experience with a heavy lift rig. Haven't ventured out with the inspire at low temps yet

    Oh and battery warmer... Looked again and don't see that helping much. Insulation is what's needed. Or better weather!
     
  9. Kilrah

    Joined:
    Feb 3, 2015
    Messages:
    1,881
    Likes Received:
    728
    Again when you see that issue please look at the battery info page for total and cell voltages and if possible get a screenshot, while still in the air (obviously 5cm above ground just before landing).
    Seen many reports of that issue but unfortunately absolutely nobody thought about looking at the rich data we have at hand to actually try and understand what the problem is.
     
  10. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,718
    Likes Received:
    3,871
    +1

    The Inspire App gives you good real time info on mAh left (and therefore consumed) as well as individual cell voltages down to 0.1v and battery temp. During flight I regularly flick into this page just for a visual indication of what's going on. You are able to see instantly whether there is a large imbalance between cells under load and therefore avert a potential problem.

    As an aside... ALL Batteries no matter what their chemical makeup perform less efficiently in lower temperatures. If you are flying at below freezing temperatures expect your packs to perform at anything up to 50% less than in warm temperatures. Although in reality it may not be that severe a reduction it does not hurt to ere on the side of caution. This means if you usually get 15 minutes out of your pack, think about bringing the Inspire back to you (and certainly away from water) after about 7 or 8 minutes. Cold temperatures means your cells will not give up their charge as easily under load and may not perform as expected when a demand is put on them..... Be warned people.
     
  11. Quadpilot

    Joined:
    Jul 16, 2013
    Messages:
    624
    Likes Received:
    308
    Location:
    Chaska, MN
    Echoing the above comments by @The Editor and @Kilrah, it's important to keep the batteries as warm as possible in flights when the temps are low. Keeping the batteries warm before flight is only half the battle. During flight, insulation is the only solution. I have five batteries and only one set of battery insulators provided by DJI, so I made replacements for the battery insulation out of 1/8 in neoprene sheets with a sticky adhesive. I also made a battery compartment wrap with 1/4 in neoprene sticky that wraps around the outside of the battery compartment. I have had good results in 0-10 deg F (minus 18- minus 12 C), with the battery temp at app 20 C at the end of a 10 minute flight. Speed and altitude (and wind) have some bearing on the temp loss during flight, obviously.The attached images show my stickies and wrap (just use the supplied battery stickies from DJI as a template).

    The neoprene sheets can be purchased on amazon: http://www.amazon.com/gp/product/B001GAD5G4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

    Granted, I'll have enough neoprene that it'll last for years, but the stuff works for me. :D
    IMG_0194.jpg IMG_0195.jpg
     
    SixtyMike, LAP, Mazz and 1 other person like this.
  12. jon b

    Joined:
    Jan 8, 2015
    Messages:
    394
    Likes Received:
    129
    Location:
    Chicago
    Yep, that's gonna help a lot and thanks for the source of sticky backed neoprene
     
  13. Mazz

    Mazz Moderator
    Staff Member

    Joined:
    Aug 9, 2014
    Messages:
    944
    Likes Received:
    585
    Location:
    NY
    Ya I have been using the battery "covers" for temperature ever since I started flying my I1. It has repeatedly been in the negatives and despite knowing I probably shouldn't fly in -15 degree F sometimes you just have to (usually I just want to fly). I actually did experience a funny battery situation similar to this but that was around when I got the inspire in round 1. It will certainly fly cold though I can attest to that. No issues since then.

    I'm curious, were your batteries room temp to start with? Were they very cold when you brought them in?
     
  14. mechanicus

    Joined:
    Nov 23, 2015
    Messages:
    2
    Likes Received:
    1
    I experienced exactly the same problem. It was 7degrees above zero so not really cold. I did not make any strange move. The inspire was hanging still in the air when suddenly my power dropped from 51% to 4% within less than a second. I scared the hell out of me. Having the X5 hanging under the inspire this makes me insecure to fly. I returned the batteries to the dealer and I get a full replacement from DJI with the garanty that my problem is solved. In other words it's not going to happen again. Fingers crossed.

    Check 1'58" for the magic to happen
     
  15. The Editor

    The Editor Moderator
    Staff Member

    Joined:
    Aug 7, 2013
    Messages:
    6,718
    Likes Received:
    3,871
    It will if you start your flights without a fully charged pack each time!
     
  16. mechanicus

    Joined:
    Nov 23, 2015
    Messages:
    2
    Likes Received:
    1
    So I can't fly move location and fly again if I don't charge up to a 100% in the meanwhile? That's bollux.

    I charged a day before and somehow it dropped (within a night) to 63%
    I say bad product (or at least firmware), in any case this should not be happening and makes the whole thing dangerous. You have to agree on that. Imagine trying to get the quad back and you don't make it home. The damage it could make!!

    I purchase a pretty expensive machine, expensive lens and a few expensive batteries. I expect some guarantee I won't fall from the sky. At least not without me telling it too.
     
    Shemp likes this.
  17. crashburn

    Joined:
    Jan 3, 2015
    Messages:
    310
    Likes Received:
    160
    I had sudden battery drop, from 45 to 1%, with a 100% charged battery, and autoland while about 800 feet from home, so BEWARE.
     
    mechanicus likes this.
  18. Shemp

    Joined:
    Jul 25, 2015
    Messages:
    23
    Likes Received:
    2
    What's the warranty on the 47's?
     
  19. ddublu

    Joined:
    Jul 1, 2014
    Messages:
    317
    Likes Received:
    11
    That's cool. How sticky is the adhesive? Does it come on and off?
     
  20. sdschuetter

    Joined:
    May 17, 2015
    Messages:
    14
    Likes Received:
    2
    Location:
    Michigan
    How long was it charged to 100% before the flight?
    6 months