Discharge Flight the Battery [Phantom 3]
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MILESTONE
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Flight distance : 1524291 ft
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Hi All,The Flight Battery is programmed to discharge when the Capacity >65% automatically.

Do you discharge the Battery manually? What is your method Way to discharge it ?

I have tried to arm the motor of Quadcopter to spin without propellers for discharging the Battery from 100% down to 65%. And it takes about 1 hour.
The Maximum Battery Temp is 47 Degree C when the battery decharging, and it is over the recommended allowable temp on Manual (40 Degree C)
The Motor itelf do not have any significant temp rise , but i can feel the belly of the Quadcopter is quite hot (The "Gimbal Module" seem reach 60 Degree C , and  the " vision positioning module" is about 50 Degree C.
I feel that the over temp on battery might do more harm than fully charge on battery.
And if the Quadcopter is leave arming and unattended, it could go up to quite high (Maybe 60 Degree C , if the Software do not stop it).

I feel that it would be better to leave it alone , and let them discharge automatically.
i have just bought the LiPo Battery Storage Bag, for better protection.
Will it cause over temp during automatically discharge, if the battery is packed in LiPo Bag?
And What is your Experience ?



2016-3-6
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arock387
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If I havnt flown for a few days and I have an extra hour I will manually drain the batteries by taking the drone out for a spin till it gets to about 10 percent than ill charge that battery to max.
2016-3-6
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Not A Speck Of
lvl.4
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My 2 cents:
  • I have no experience manually discharging the smart batteries (P3P) by any means.
  • That said, I've had no problems letting them discharged normally while stored in the case.
  • I have only had batteries get warm while using them in the craft, never from just sitting there.
  • It seems to me that since the motors of any quad only has so many flight hours (mean time between failure), that running your craft around just to discharge batteries is using up valuable life of your craft.
  • I don't know if DJI has an approved method (and I wouldn't use such a method without a DJI nod), but some smart guy out there should be able to find a way to discharge batteries outside he craft. I have other devices (Nikon DSLR) with battery chargers that have a discharge function (sometimes called conditioning or battery calibration).
  • That said, if the battery has built-in discharging as you said, we shouldn't need to discharge it by flying our bird or using some external discharger.


This is all just seat-of-my-pants conjecture. Any corrections, or different opinions?

Chris
2016-3-6
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nigelw
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Not A Speck Of  Posted at 2016-3-6 16:17
My 2 cents:
  • I have no experience manually discharging the smart batteries (P3P) by any means.
  • ...

  • Discharging batteries by any method, even self-discharge, counts as the same thing.  They have still been through one charge/discharge cycle.  I don't know if the app shows it on the counter or not, may be worth checking.  Personally I try to get some use out of a charged battery if I've not used it as planned, even if it's just a local practice flight.
    2016-3-6
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    DJI-Ken
    DJI team
    Flight distance : 1515312 ft
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    The easiest way is to let them auto discharge. I have mine set to 3 days and I leave them in the DJI hard shell backpack and they are totally fine.
    If you want to manually discharge, the best way (and also best way for calibrating) is to power up the aircraft only and just let it sit there for a few hours until it shuts itself off.
    You sound like you care about your batteries and want to take care of them. Another suggestion I have is to only discharge them to 50% for the first 10 flights and always calibrate them at 20 flight intervals.
    One of mine has 57 charges and still has 98% life left.
    2016-3-6
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    Hawks100
    lvl.4
    Flight distance : 134580 ft
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    Ken.
    How do you Calibrate these Batteries..
    2016-3-6
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    miminiska
    lvl.1

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    Hawks100 Posted at 2016-3-6 14:30
    Ken.
    How do you Calibrate these Batteries..

    Good question. How do you calibrate a batt?
    2016-3-6
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    Slyone
    lvl.2
    Flight distance : 1715308 ft
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    DJI-Ken Posted at 2016-3-7 03:01
    The easiest way is to let them auto discharge. I have mine set to 3 days and I leave them in the DJI ...

    Hi Ken,

    I wasn't aware that you can calibrate the batteries how do you do this?
    2016-3-6
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    DJI-Ken
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    Slyone Posted at 2016-3-7 12:16
    Hi Ken,

    I wasn't aware that you can calibrate the batteries how do you do this?

    The directions are in the manual and battery guide, but after 20 charges you drain the battery down to 8% or so and then let it sit for 30 minutes then fully charge it on the stock charger and that's it.
    If you want the best calibration you can get, power up the aircraft and let it sit until it powers itself off.
    2016-3-6
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    nigelw
    lvl.4
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    DJI-Ken Posted at 2016-3-7 04:35
    The directions are in the manual and battery guide, but after 20 charges you drain the battery dow ...

    Isn't 8% a little too close to causing battery damage?  For some reason I have it in my head they shouldn't have any cell at less than 3.3v

    I've not tried it yet though so it could be above that voltage anyway.
    2016-3-7
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    DJI-Ken
    DJI team
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    nigelw Posted at 2016-3-8 04:09
    Isn't 8% a little too close to causing battery damage?  For some reason I have it in my head they  ...

    I've only drained it to 8% then charged. I have not powered the aircraft back up to see what the resting voltage is. I just leave it in the aircraft powered up until it shuts itself off.
    2016-3-7
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    AG0N-Gary
    Second Officer
    Flight distance : 700846 ft
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    I have mine set to self-discharge after 3 days.  Be aware that it takes a few days to discharge, and that if you hit the button to check the level, that resets the counter and it will be another 3 days before it begins to discharge.  When I tested it, it did not seem to cause it to stop discharging when I checked the level once it had started to discharge.  How did I know it had started?  It was slightly warmer than the battery that wasn't discharging.  I got my IR thermometer and checked it.  It was between 1 and 1.5 deg F warmer than the other battery stored right next to it until it had discharged down to approximately 50%.

    As for how I normally discharge it, it only takes a few minutes of air time to run it down to 50%.  Just fly it!  If nothing else, hover it, but it will use more battery to go up and down and fly around.  Be very careful about going full throttle, or maneuvering erratically.  You might stress the battery if it is cold and crash it due to shutdown.  Hovering it at least provides some cooling for the motors and electronics.
    2016-3-7
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    rvb100
    lvl.1

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    Could you not rig up some type of Dc light bulb or a DC fan  to discharge the battery without putting hours on the copter motors? And a volt meter hooked into the circuit would tell you when you were down to "X" volts.......Yes?
    2016-3-8
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    nigelw
    lvl.4
    Flight distance : 518084 ft
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    rvb100 Posted at 2016-3-8 10:53
    Could you not rig up some type of Dc light bulb or a DC fan  to discharge the battery without puttin ...

    Yes...but motors are relatively cheap & last almost forever.

    Or put another way, if you need to discharge the batteries because you haven't flown it for a few days, depreciation of the drone will cause your cost per flight to be much more than the cost of worn motors over the first couple of years.
    2016-3-8
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    Not A Speck Of
    lvl.4
    Flight distance : 666493 ft
    United States
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    I've had my batteries since last summer and only just now ran through the calibration and re-charge process.

    Then I tested the life of the battery via the process in the owners manual. It seems that the batteries are still at > 95%, but perhaps I'm doing it wrong.
    Here's what I'm doing
    • Press and hold the power button
      Solid red power light, 4 solid green lights
    • Wait for ~5 seconds
    • The red power light starts blinking
      The 4 green lights remain solid, none blinking


    Did I do it right? Does that mean that I'm > 95%?

    Thanks,
    Chris

    2016-3-8
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