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Batteries at 97%

Discussion in 'Phantom 2 Discussion' started by hey_moe, Dec 11, 2014.

  1. hey_moe

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    These batteries are all new, within a month are so. But when I fully charge them on the DJI Vision app it only shows 97% or 95%. The battery on the transmitter when fully charge shows 100% when charged. Is this normal. and why doesn't it show 100%.
     
  2. Hughie

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    Re: Bateries at 97%

    I dont know. But it is possible that the max battery capacity varies slightly from cell set to cell set.

    If the working range is (say) 3.2v to 4.0v that is only 0.8v per cell (or 2.4v overall). Based on that rough estimate 3% is only a difference of 24mV per cell.

    The other thing is that the ceiling capacity could improve after its first cycle.
     
  3. hey_moe

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    Re: Bateries at 97%

    Thanks, also is it battery to run the battery completely down. I usually take it to a point the alarm goes off on the app then change the battery. Different threads suggest different things.
     
  4. Hughie

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    From what I understand even if you leave the battery fully charged, the battery logic will automatically discharge it after about a week. I believe the ideal long term storage level for LiPos is 50-60%.
     
  5. Loaderbull

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    Re: Bateries at 97%

    From what I understand you should never fully discharge lipo's past their critical level of about 2.9V per cell (there or there abouts). However with these batteries 0% is not really 0% capacity. So when the battery tells you it is at 0% and cuts off, it is still well within that critical level. I have read that you should discharge the batteries down to 0% (as the battery displays not true 0%) every 20 flights or so to maintain its health.

    One way would be to fly, then leave the Phantom on until it shuts off? Others use car light bulbs of 21Watts or so connected. There are ways, choose which method suits you. I'm sure others will chime in with how they prefer to do it - but I leave my Phantom on after a flight and let it run down that way.
     
  6. Loaderbull

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    You are correct, however it is approx. 10 days I think? Pain when you want to fly on the spur of the moment and you have only 50% battery, but the long term gain is you maintain a better battery capacity for longer.

    Storage is 40 to 60% I recall for Lipo's. Been doing it for years now with other model aircraft, leaving them fully charged results in them puffing, leaking etc which has happened to me prior to storing them at 50% for long periods.
     
  7. jason

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    Re: Bateries at 97%

    This info is on the bottom of your assistant software.
    "It’s recommended to charge and discharge the battery thoroughly once every 20 charge/discharge cycles. Users should turn on the battery installed in the aircraft, discharge statically until there is less than 8% power left or until the battery can no longer be turned on. Users should then fully recharge the battery to maximum capacity. This power cycling procedure will ensure the battery is working at its optimal level."

    You can monitor the discharge of your battery using the assistant software. I do this with all my batteries or you can use loaderbull's method with the light bulb. You should also read the latest user manual page 20 for your phantom
     
  8. hey_moe

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    Hey guys thanks for all the info and also for taking the time to explain it to me, Mike