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Battery percentage - Long term storage

Discussion in 'Inspire 1 Help' started by Mr Phantom, Dec 13, 2015.

  1. Mr Phantom

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    Do the Inspire 1 batteries need to be stored at a certain percentage when i want to store them long term, like at least 3 month storage time or more?

    I have already stored one TB47 battery for about one and a half month and the battery is at 2 percent, i also noticed that on the GO app there is a cell voltage difference between the highest and lowest cell voltage of 0.10 V, is that acceptable?
     
  2. msinger

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    The batteries should be stored at between a 50-30% charge. If your battery is really at 2%, then you are probably damaging it.
     
  3. Mr Phantom

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    oh, that was not fun reading, i was under the impression that since it is a "intelligent battery" it will sort itself? Is this not the case?

    I am charging the said battery right now.
    So how will i know if the battery is damaged, is it if the cell voltages differ to much?
    Is a maximum cell voltage difference between highest and lowest of 0.10 Volt acceptable?
    And also will not the GO app notice if the battery is damaged and notify the user in the app?

    And even if the cell voltages looks okay can i trust that the battery will not make a voltage drop in flight because of the battery being damaged due to wrong storage?
     
    #3 Mr Phantom, Dec 14, 2015
    Last edited: Dec 14, 2015
  4. The Editor

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    Page 1 under "Battery storage and transportation"
    http://dl.djicdn.com/downloads/inspire_1/en/Intelligent_Flight_Battery_Safety_Guidelines__en.pdf
     
  5. Mr Phantom

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    I hadn´t seen that PDF about the battery safety guidelines, I've only read the user manual but didn't found the answers to any of my questions in the user manual.

    Well this PDF answered the question on which percentage the battery should be stored, if anyone knows the answers to my other questions i would be glad to hear them out?

    And except saying that the battery should be long time stored at around 30-50 percent it also says that the battery will enter hibernation mode when depleted and stored for a long time, so it doesn't sound to damaging according to the battery safety guidelines to store them at less than 30 percent? Maybe its more damaging to store them at a too high percentage? Or am i totally wrong?

    Anyway, I've just charged the battery to 69 percent, i will have to manually discharge it to less than 50 percent.
    Now after charging the battery the maximum and minimum cell voltage difference is only 0.01 Volt, i guess that must be considered normal? If i remember it correct the acceptable difference is up to 0.2 V or was it 0.02 V?

    What about the storage percentage for the RC battery, is it the same 30-50 percent? It didn't say anything about that.
     
    #5 Mr Phantom, Dec 14, 2015
    Last edited: Dec 14, 2015
  6. The Editor

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    All lipos should be stored at circa 50% charge or around 3.86v per cell for longer term storage.
    A lipo should not be kept at either a charged or depleted state for any length of time more than a few days. The same goes for the remote battery - its a lipo, treat it the same for storage purposes. As the remote battery is only a two cell and has low current draw it is not so critical bit still good practice.
    Your difference in cell voltages should be small. 0.02 is perfectly acceptable, 0.2 is not unless it is under heavy load like climb out. You may then see a little imbalance between cells but these should equalise when the load is lifted. Also, the cells are balanced during each charge cycle (that's what takes the time during the final stages). You do not need to worry about your 69% pack....it will self discharge to the required storage voltage after the set number of days (whatever you have set your batteries to default to in the app)
    Finally, stored lipos (at 50%) prefer colder environments than warmer ones (but not freezing). Just be sure to bring the packs up to ambient temp before charging/using.
     
  7. Mr Phantom

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    Thanks for some useful information. Well then 50 percent that is.

    I just got the impression that it was okay to store them at a low percentage since the DJI battery safety guidelines said that the battery will enter hibernation when the battery is depleted and stored for a long time, and that it wakes up from hibernation next time the battery is charged.
    Aha, it was 0.02 V that was acceptable cell volt difference, i shall remember that.

    But okay, then i know that i shall try to keep the battery at around 50 percent when store it a longer time, that was my main question.
    Thanks for the help.