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Charging up to storage level

Discussion in 'Pro/Adv Discussion' started by williamjamesfpv, Oct 9, 2015.

  1. williamjamesfpv

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    Hi guys - So, instead of charging my battery 100% and then dropping it down to 50% via flying, I decided to just charge it up to the 50% mark. However, I noticed that by charging only up to the 50% mark, that my cells aren't balanced. For example, 3.85v, 3.84v, 3.87v, 3.86v . I have 3 questions regarding this:

    (1) If I am leaving my battery in storage mode, does it matter if there is a minor discrepancy in voltages?

    (2) By having a minor discrepancy, does the battery discharge any faster/slower?

    (3) When I do decide to finally charge it to 100% (as in after my storage period, and prior to flying), will my cells all balance?
     
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  2. msinger

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    That discrepancy is pretty standard. If there is a large discrepancy and the battery is fairly new, then try running the battery in your Phantom until it shuts off and recharge it. That normally rebalances the cells.
     
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  3. williamjamesfpv

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    My main concern is whether it will all balance in the end when I'm ready to fly (as in after I come out of storage mode). I'm also wondering if it'll discharge any faster/slower as a result of the discrepancy. My batteries are pretty new (ie: less than 20 charges)
     
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  4. msinger

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    The cells should be close, but they don't have to match 100%. I don't think the cells will ever auto rebalance themselves. Completely discharging the battery is the only way to rebalance them. In your case, I wouldn't do that since you do not have a large discrepancy. If you would have a large discrepancy and completely discharging and recharging does not fix the problem, then the battery is most likely damaged.

    Sure -- each cell in the battery will discharge/recharge faster if the full capacity is higher/lower than the next cell. The discrepancy in your battery is minor though. You have nothing to worry about. On a similar topic, it's a good idea to keep an eye on the individual cell voltage when flying.
     
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  5. williamjamesfpv

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    Sorry, but I'm confused. Why would they never rebalance themselves? My cells were all balanced in a discharge state tonight. Then, I went to charge it up to 50% and now they are slightly mismatched. So if I fully charge it to 100% it won't balance itself out now? Please tell me that I've misunderstood you.
     
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  6. msinger

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    I don't know. Try it and report back. I'm just confirming that you should not be alarmed if the cells do not match 100%. A slight discrepancy is normal.
     
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  7. williamjamesfpv

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    Okay, wanted to report back after I fully charged the battery. My cells are at 4.29v, 4.33v, 4.33v, 4.30v. Does this sound about right for a battery that has less just <20 charges on it?
     
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  8. msinger

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    It's an acceptable discrepancy. DJI recommends completely discharging and recharging every 20 charges. When you do that, the cells should balance themselves out. There still could be a slight discrepancy even after doing that, but most people find it at least reduces the discrepancy.
     
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  9. williamjamesfpv

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    Ah! I see.... now its all starting to come together. Going back to like all your posts in this thread now. You've been very helpful. Thank you and very much appreciated :)
     
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  10. Pete Leare

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    I agree, msinger is one of the most helpful people on this forum
     
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