Welcome to PhantomPilots.com

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

what is the best way to drain your battery.

Discussion in 'General Discussion' started by ccase39, Mar 29, 2015.

  1. ccase39

    Joined:
    Jan 3, 2015
    Messages:
    471
    Likes Received:
    17
    I flew it until less than 30% once and then just left it on. It took a good hour before getting below 8%. What do yall do?
     
  2. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Whatever you do, don't leave the motors running after landing.
     
  3. locoworks

    Joined:
    Jul 4, 2014
    Messages:
    471
    Likes Received:
    10
    Just fly it.
     
    IflyinWY likes this.
  4. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Can't argue with that.
     
  5. Ozziebattler

    Joined:
    Apr 16, 2014
    Messages:
    114
    Likes Received:
    10
    Location:
    Fernvale Queensland Australia
    Keep it close and just fly it
     
  6. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,030
    Likes Received:
    5,602
    Location:
    US
    A battery discharger like this one is a good option if you aren't able to fly.
     
    #6 msinger, Mar 29, 2015
    Last edited: Nov 4, 2015
    pb7424 likes this.
  7. thestone11

    Joined:
    Mar 3, 2015
    Messages:
    296
    Likes Received:
    32
    Location:
    Alberta Canada
    Wonder how long is going to take that little bulb to discharge your battery. My suggestion is still fly it if possible, way faster.
     
  8. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    If you look closely at the picture of the bulb, it's 35 watts.
    That way if the battery doesn't start a fire, the bulb will. :rolleyes:

    No offence msinger
     
  9. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,030
    Likes Received:
    5,602
    Location:
    US
    No offense taken. But, what exactly are you trying to point out?
     
  10. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    A 35 watt bulb burns hot.
    A 35 watt bulb should drain the battery at a fairly good rate.
     
  11. msinger

    Approved Vendor

    Joined:
    Oct 30, 2014
    Messages:
    19,030
    Likes Received:
    5,602
    Location:
    US
    Yes, bulbs get hot. Thanks for the warning... I think? :confused:
     
  12. Narrator

    Joined:
    Nov 15, 2014
    Messages:
    347
    Likes Received:
    6
    Location:
    Melbourne, Australia
    Page 10 of the manual recommends a full charge and discharge to 8% every 20 cycles. If you fly it, you can't get down to 8% without a lot of ground idle or fighting the autoland. Perhaps fly it to 15%, then turn the props off to get it to 8%. Definitely something I need to do.
     
  13. Larry L

    Joined:
    Oct 17, 2014
    Messages:
    671
    Likes Received:
    39
    Location:
    Copperas Cove, Texas
    I just flew until it got close to RTH, I hovered
    what I did was fly mine until about RTH, I then hovered it & held on to legs until 8% & it shut down. Easy Peasey!
     
  14. Narrator

    Joined:
    Nov 15, 2014
    Messages:
    347
    Likes Received:
    6
    Location:
    Melbourne, Australia
    That's something I wouldn't do.
    Once you've flown it, having the motors idle for any period of time risks overheating the ESC's. Having learned that, I only ever have the motors running if it's flying.
     
  15. Larry L

    Joined:
    Oct 17, 2014
    Messages:
    671
    Likes Received:
    39
    Location:
    Copperas Cove, Texas
    Narrarator, It is hovering with props on. Hovering close just waited till it flashes red, & watched on iPad for 8% & then it turned off. Hovering, it is not idling so there is enough wind flowing over components. I'm just holding firmly with both hands to landing gear. Same thing as the gentleman that ran a dowel through the landing gear with weights on it & ran it until turned off. I just would weather hold it instead of using dowels just i case vibration knocked one of weights off or it broke free. That is the easiest way that I have found to drain it to 8% without overheating. You just have to pay attention.
     
  16. Narrator

    Joined:
    Nov 15, 2014
    Messages:
    347
    Likes Received:
    6
    Location:
    Melbourne, Australia
    cool.. I understand now ;)
     
  17. johnp44

    Joined:
    Jan 29, 2015
    Messages:
    338
    Likes Received:
    75
    Hi,

    You probably already figured out a way to discharge, but maybe this added info might help you out.
    The DJI battery will automatically cut off at 9.0 Volts whenever it is being discharged. It will not allow the battery volts to drop below that point. So you could use 12 volt bulbs or a hi wattage 5 or 10 ohm resistor to discharge the battery to that point (but try not to exceed a rate of about 2 amps). Example, a 10 ohm resistor connected to battery at 10 volts equals about 1 amp discharge rate. Deep cycling isn't really needed to be completed every flight, but DJI suggests deep discharging every 10 or so flights. I do mine by at least 15 flights and all seems well.

    After you deep discharge, it would be a good idea but not required to slow charge for the first 10-15 mins. I purchased a DJI spare part battery connector so I can charge/discharge the battery outside of the Phantom. The stock chargers start out charging at about 3.5 amps and taper down to just a few milliamps at the end. This is where a programmable lipo charger/discharger would be very useful. Because if you can charge the battery at about half that rate initially will "help" prevent any damage or swelling of any cells and will IMHO prolong the battery life and flight times.

    I am sure others have different ways of doing battery maintenance but I have batteries with almost a hundred cycles that are still flying strong.

    Hope this helps!
     
  18. Larry L

    Joined:
    Oct 17, 2014
    Messages:
    671
    Likes Received:
    39
    Location:
    Copperas Cove, Texas
    I write like I talk:( LOL
     
  19. Larry L

    Joined:
    Oct 17, 2014
    Messages:
    671
    Likes Received:
    39
    Location:
    Copperas Cove, Texas
    Thank you John, great info. I guess everyone has their different way to do it.
     
  20. IflyinWY

    Joined:
    Sep 12, 2014
    Messages:
    3,470
    Likes Received:
    939
    Location:
    Where the deer and the antelope play
    Hey johnp44, what kind of bird do you have. Sounds like great info, but my FC40 battery isn't as smart as what you have. I can kill em deader than a door nail.