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LiPo Battery question for a real LiPo battery Guru

Discussion in 'General Discussion' started by JKDSensei, Sep 14, 2015.

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  1. JKDSensei

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    Dear LiPo Battery Guru,

    I know enough about LiPos to pose some really dumb questions so here goes...
    I have a DJI OEM 2200mAh Lipo Battery. I also recently purchased a Black Magic 2700mAh battery.

    My Phantom is set up so that the red battery warning light (first alert) comes on at 11.3v (no load) and 10.70v (loaded) Loss = .60v

    With both batteries fully charged at 12.60v total and 4.20v per cell....
    The 1st battery warning light comes on with both batteries at almost exactly 8 minutes
    So this seems to tell me the batteries have the same capacity to 11.3v (10.70v loaded)
    Si I'm thinking the BlackMagic battery is fake, fried, not really a 2700mAh battery etc...

    But here's the oddity.....
    When I recharge the batteries, the OEM DJI battery will usually absorb about 800mAh of power
    The BlackMagic 2700mAh battery shows it absorbs closer to 2400mAh
    (I call it "absorb"...it's just how I put it).

    The internal resistances are good. all cells on both batteries 006 to 004. (None more than 006 and none less than 004)

    I need to check the voltage on the BlackMagic battery at that point next time but I do believe the UNLOADED voltage last time was 11.2 just as expected.

    If the BlackMagic battery is using significantly more power, why is the Phantom not running longer?
    The Black Magic battery is only 24 grams heavier. That 24 grams shouldn't be using up ALL that extra capacity should it?
     
  2. Buckaye

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    I know you said the new battery is 24 grams heavier... but what percentage heavier is it than the OEM battery... I ask because your battery should, in theory, be seeing a 18.6% increase in output time, but that will be eaten up some by the additional weight.

    The other thing I would ask is are you flying in exactly the same conditions? IE: Both just hovering, no wind, etc etc.... because if the conditions are different that could also lead to a battery draining faster...

    Just some food for thought....
     
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  3. JKDSensei

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    Yes. Good thoughts.
    The conditions are the exact same. Indoor hovering until first battery warning.