Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Self auto discharging batterie on P3?

Discussion in 'Pro/Adv Discussion' started by maher, Jul 10, 2015.

  1. maher

    Joined:
    Dec 2, 2013
    Messages:
    90
    Likes Received:
    14
    Location:
    Drummondville, Québec, Canada
    I have 4 batteries for my P3, all of them are set to auto discharge after 10 days but even after 2 weeks with no usage they always stay 100 % charged no matter what! Checking a batterie charge by pressing its button is may be resetting the auto discharge timer...

    I don't see an option to turn on and off the auto discharge feature of the batterie on the Pilot app so I'm quite puzzled by that feature. How hot can become a batterie when auto self discharging kick in? Is it safe to let the batteries auto discharge in a backpack or a hard case without any mean for the heat to easily dissipated?

    Maher
     
  2. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,096
    Likes Received:
    5,623
    Location:
    US
    DJI does not document that anywhere -- but, people have reported that pressing the button resets the timer.

    You cannot disable it. It's only possible to change the number of days to wait before the auto discharge process initiates.

    I do this. My batteries are never hot... or even warm.
     
  3. Morphious

    Joined:
    Jun 19, 2015
    Messages:
    205
    Likes Received:
    83
    I set mine to two days and it works.
     
  4. silverstoned83

    Joined:
    Jun 13, 2015
    Messages:
    217
    Likes Received:
    64
    I too set mine to two days and it never dropped in charge level. I also was checking it's state of charge prior to two days.

    My suggestion is to not rely on this feature. The longer they stay charged, the shorter their lifespan (cycle count) will be.

    I'm glad that the feature exists, but it would have been better if they also allowed the user to manually start the discharge process.
     
  5. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,256
    Likes Received:
    1,617
    Location:
    Palm Beach Co.- FL
    It is widely believed that checking the status resets the timer as this constitutes 'use'.


    Try repeating with out 'peeking'.
     
  6. RoyVa

    Joined:
    Apr 10, 2015
    Messages:
    2,246
    Likes Received:
    449
    Location:
    Virginia
    Self discharging does not have a load on the battery so it will not get hot. No concern there by having it in a compartment or case.
     
  7. silverstoned83

    Joined:
    Jun 13, 2015
    Messages:
    217
    Likes Received:
    64
    I'd like to know if anyone has tested this to make sure that it's safe to do inside a sealed and insulated case. This sounds like an accident waiting to happen and is not something I would even think about trying. Heat must be released in order to discharge the battery. I understand that it's discharging at a very low rate... But when you add insulation to the scenario, the heat builds. Long exposure to unnecessary heat should be avoided, always. Not just for the sake of the battery, but also to reduce the possibility of a fire.
     
  8. Alex Kiritsis

    Joined:
    Apr 12, 2015
    Messages:
    180
    Likes Received:
    32
    Mine have discharged inside their foam inserts without issue. At the rate they discharge, u will not feel the slightest amount of heat from the battery.
    The paranoia within this forum is rampant. Phantoms falling out of the sky because of firmware issues, that could potentially land on little babies in strollers and five year old on playgrounds. Laughable. Some people on these boards could use their own personal bubble. Live a little people.
     
    Buckaye and N017RW like this.
  9. silverstoned83

    Joined:
    Jun 13, 2015
    Messages:
    217
    Likes Received:
    64
    People have lost their house over LiPo fires due to assuming too much. Sorry for trying to be sure... Which, if you didn't know, is completely different than being paranoid.

    One of the worst qualities of Phantom pilots is their ability to make assumptions rather than see the importance in making sure they fully understand something before trying it out.

    Laughable...? Say that next time someone's house burns down due to listening to someone that's sending the wrong message rather than spreading awareness. The point is not to make everyone worry the second their LiPo is anything but cool to the touch.... It is to prevent the most unfortunate and unpredictable things from happening.
     
    #9 silverstoned83, Jul 10, 2015
    Last edited: Jul 10, 2015
  10. Alex Kiritsis

    Joined:
    Apr 12, 2015
    Messages:
    180
    Likes Received:
    32
    My comment was not steered toward yours. Sorry, I should have made that clear. I was talking about this forum in a whole. I understand the risks of lipos and a lot of other things. My point was that things happen for a reason whether it's intentional or not and life would be a complete bore if we constantly analyzed every single potential. When it's your time it's your time.
    My five year stands rite next me when I fly my P3 and we both understand the risk. I'm a very safety conscious person and even take many OSHA courses on it. If we constantly said to ourselves... this could happen or this could happen. We would never fly our drones. Once again not steered toward u. Your comment just sparked mine.
     
  11. walker16

    Joined:
    Jun 18, 2015
    Messages:
    63
    Likes Received:
    42
    In post #2 he also addressed the fact that he discharges in a hard case with no issue as do I.

    I totally see Alex's point tho. A lot of threads and comments are pretty laughable on this forum. At some point someone's concerns and paranoia should trump there need to own one of these

    The post about someone that has had there's for over a month and is scared to fly it cause they heard a few people say the firmware caused it to crash! Maybe just go buy a basketball or something. Maybe this hobby isn't for everyone! *rant over*
     
    doomclam and Alex Kiritsis like this.
  12. envisionabove

    Joined:
    Apr 13, 2015
    Messages:
    1,036
    Likes Received:
    387
    Location:
    Tim in San Diego
    Basketballs can break fingers, shatter windows under a baby sleeping in his crib, cuase children to run blindly into the street in front of a car! How dare you say basketballs are safe. The nerve of some people I tell yeah...
     
    walker16 and Alex Kiritsis like this.
  13. silverstoned83

    Joined:
    Jun 13, 2015
    Messages:
    217
    Likes Received:
    64
    Again, this is leaving a lot of unknowns unanswered. Was the lid left open? Was it in a cooler place? Etc... Simply saying that it's fine to do because I've done it means absolutely nothing in terms of knowing whether it's safe for everyone to do. There are precautions that should be considered whenever you store a LiPo and what is being suggested here is completely ignoring those precautions.

    Do it at your own risk.
     
  14. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    Lipo care is one of those holy war topics - I used to see very VERY heated debates on helifreak on all the various theories about proper charging, discharging, disposal (salt water method vs. lightbulb and sand vs. whatever). Silverstoned83 isn't wrong... Lipos misused have caused fires. My personal experience is that the smart battery discharge in a case has not been an issue. I have never felt any measurable warmth on the battery after they have been auto-discharged. That said... if YOUR preference is to do something else... and you're convinced that your way is safer... then by all means keep doing it.
     
  15. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    I'll answer from my personal experience... No the lid was closed. It was in my air-conditioned house 72 degrees on tile... when I removed the batteries from the case I felt absolutely no warmth and it didn't matter if I picked them up on day 7, 8, 9 ....12....14 or whatever. But, I don't begrudge you any of your safety concerns. You gotta do what helps you sleep at night. I have not seen any issues and furthermore have not read anywhere where auto discharge has yet to have caused a fire.
     
    silverstoned83 likes this.
  16. N017RW

    Joined:
    May 2, 2014
    Messages:
    6,256
    Likes Received:
    1,617
    Location:
    Palm Beach Co.- FL
    Lets put some numbers to this and see how risky it may be...
    (Please feel free to correct any issues)

    Battery voltage at full charge - 17.4
    Battery capacity- 4480mAh
    Discharge duration approx 48hours
    Initial level at start- 100% charge
    Final or cut-off level- ~50% charge


    1st order approximations:
    50% charge = 2240 mAh = 2.24 Ah

    2.24Ah / 48 hours = .0466 Ah

    17.4v x .0466a = 0.8108 Watts!

    Just fun for academics sake.
     
    walker16 likes this.
  17. walker16

    Joined:
    Jun 18, 2015
    Messages:
    63
    Likes Received:
    42
    I guess someone could ask dji there option but I'm sure they would say to store in a cool dark place in a fireproof box just to cover there ***!
     
  18. silverstoned83

    Joined:
    Jun 13, 2015
    Messages:
    217
    Likes Received:
    64
    Thanks for sharing, this is all that I wanted to verify. It's sad how butt hurt people can get on this forum when all someone is trying to do is look out for everyone's well being.
     
    #18 silverstoned83, Jul 10, 2015
    Last edited: Jul 10, 2015
  19. Buckaye

    Joined:
    Aug 24, 2014
    Messages:
    1,557
    Likes Received:
    420
    Location:
    Orlando
    ONE POINT 21 GIGAWATTS?!?