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Professional battery cell voltages

Discussion in 'Phantom 3 Help' started by NEAL, Jul 27, 2015.

  1. NEAL

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    Hi, could anyone help me with a question about battery voltage, iv'e just charged my p3p battery till the lights went out on the charger, I turned on the phantom any will warming up the battery dropped to 98%, I checked the cell voltages and 3 showed 4.31 and 1 showed 4.25, the last time I flew down to 50% the voltages were within .01 across all four cells, the battery has been cycled 8 times and never down to more than 50%, do I need to worry, and should I get a new battery, thanks for any help
     
  2. bobmyers

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  3. NEAL

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    Thanks for the advice, I've cycled the battery 3 times and the cells are now within. 0.03, which is an improvement, still showing 100%, so will keep my eye on things, think I'll get another battery anyway
     
  4. vincey2kr1

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    I have a .05 variance as well once the batteries are lower if that helps any.
     
  5. NEAL

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    Hi, funny but when mine are discharged they are within 0.01, I do know from previous experience flying aircraft with lipo batteries that they tend to get stronger after initial use
     
  6. AlmostTan

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    Curious what more experienced pilots think an acceptable cell variance is - both while the aircraft is idle and while the motors are running?
     
  7. zincsoldier

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    My cell voltage has a variance of 0.05 at maximum and I am at 42 cycle. I notice the battery is losing 2 minutes of flight time. The battery health is still 100% though. I discharged to below 8% twice at 20 cycle. Hope that helps.
     
  8. AlmostTan

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    .05 variance while on and resting or in flight/motors started?
     
  9. zincsoldier

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    0.05 at 25% - 30% remaining. 0.01 - 0.02 at start up.
     
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  10. zincsoldier

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    I had a problem with my P3 before and I thought it was because of bad battery cell but it was not. This new P3 4S battery is much better compared to P2 3S battery.
     
  11. AlmostTan

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    Awesome, sounds like mine is normal -- thanks for sharing!
     
  12. zincsoldier

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    Did you notice a reduction in flight time as the battery is aging? Which cycle are you at?
     
  13. AlmostTan

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    I'm at my 12th cycle on it - just finishing breaking it in.
     
  14. zincsoldier

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    Too easy :) Keep us informed
     
    #14 zincsoldier, Aug 11, 2015
    Last edited: Aug 11, 2015
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  15. MattyDread

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    I got to my 10th cycle & 1 of the cells was always 0.3 lower than the others, around my 17th cycle it was 0.5.

    I've just done the 20th cycle - drained the battery to 8% as per dji instructions & all the cells are balanced again, with only 0.1 between any 4

    I thought my battery was cactus but this seems to have worked.

    Edit to add - fully charged it now shows on the app 23mins flight time, was showing 22 before the 20 cycle depletion / recharge
     
    #15 MattyDread, Aug 11, 2015
    Last edited: Aug 11, 2015
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  16. bobmyers

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    Thanks for the post-- great info!:)
     
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  17. Protocrash

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    Hi guys,

    Given this discussion I think you might be interested in this...

    Since launching the Phantom Angel (a Phantom storage discharher, more info at Phantom battery discharger) a couple of months ago I've had loads of discussions with Phantom pilots about their batteries.
    What I saw was that many new pilots were not aware of standard LiPo practices and were surprised and grateful when I shared some of what I've learnt over the years.

    So, with that in mind, I've created a concise, newbie-friendly guide to all things LiPo. If you don't know how to store your battiers, how to keep them from exploding or how to tell your watts from your amps, this guide's for you :)

    Top tips for happy Phantom batteries

    Hope you find it useful and please do send over any and all thoughts and comments.

    Proto
     
  18. bobmyers

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    Good info-- you need to correct this statement


    To overcome this DJI asks you to discharge the battery fully and then charge fully. In the process the battery counts how many mah are put back into the battery and recalibrates its calculations.
    The recommendation is to discharge it to 8% capacity-- which would not be be 0% or fully
     
  19. Protocrash

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    Hi Bob - thanks for pointing this out. Updated the guide. Cheers!
     
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