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DOA TB47 Revived - Moderator comment: BUT DO NOT COPY THIS METHOD

Discussion in 'Inspire 1 Discussion' started by chatch, Aug 14, 2016.

  1. chatch

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    Got an Inspire v2 with a spare TB47. Not sure which one was the bad one, as i tore open both boxes at the same time and lost track of which battery came with the Inspire.

    Anyways, one of them charged fine. Plugged in the 2nd battery and got a way different blinking pattern.



    that's what mine did. not my video, but same thing.

    Opened up the battery. Positive lead is connected directly to the lipo. Negative seems to go to the controller board/charge board, then another black negative wire goes from the charge board to the negative lipo terminal.

    I chewed off the coating on one of the twistie ties that came on the charger cable, shoved it between the wire insulation on both ends to bridge the gap. so the lipo is effectively connected directly to the external terminals. Plugged it in for 10 seconds(charger made a strain noise so it definitely was pumping juice into the battery), pulled out the twistie tie, and now it charges normally.

    I'll see how long the pack lasts. I'll probably end up doing the external lipo mod on this one if the cells are damaged from being discharged for such a long period of time. The TB47 i opened definitely flies 5 minutes less than the other pack.
     
  2. gazza95

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    Send it back to supplier and get a replacement. I would simply not risk using it for Inspire flights.

    Having previously "rescued" a limo cell and seen how quickly it ultimately fails I would no longer fly with one.
     
  3. The Editor

    The Editor Moderator
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    I have changed your thread title to something that will hopefully not encourage members to do the same thing.

    I cannot stress strongly enough how dangerous this can be with Lithium Polymer packs.
    The very fact your 'repaired' pack is exhibiting decreased flight performance of around 50% is reason enough to retire it and dispose of it responsibly.

    You had no way of limiting the current into the cells (other than the limit of the power supply you directly connected to the terminals - it's not a charger, it is simply a PSU).
    You bypassed the charger circuitry and connected a (thankfully regulated) power supply to your pack.

    I am only glad the pack was probably depleted and thankfully you still have a house.

    WARNING: To other members on the forum, please NEVER attempt this course of action - you may not be so lucky!
     
  4. chatch

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    I agree with Mr. Moderator, this isn't a thing for someone without electronics experience to do. And ultimately you'll be sending your Inspire out with 6 chances of a cell being bad.

    I purchased a new TB47 battery and will be picking it up from my local retailer today. Will post back here or in the Battery Mod thread with results of my shenanigans with the $160 doorstop I got with my original Inspire purchase. I've got a boat load of regular 6S hobby batteries that take a 10C charge just fine... in most cases they charge in 18 minutes on my 20 amp charger.
     
  5. chatch

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    update: 11-12 minutes this morning on Doorstop battery. landed with 46% remaining at that mark with the other battery.
     
  6. Donnie Frank

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    Mine did absolutely nothing. Dead as dead can be:

     
  7. chatch

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    that's odd. cells must be completely out of power. charging them manually is the highest risk scenario. I've burned plenty of hobby batteries this way.
     
  8. Mad_angler1

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    Yea its the DJI adapter that does the current limiting in the bulk section of the charge so the pack could receive no more current than it would through the board normally but the danger would be as the charge comes up and the pack is still receiving the bulk current from the adapter and then it all goes fukishima, If this is done for no more than 10 minutes then the the major risk is bringing a pack back to life that been depleted to low are than anything.

    My recommendation on this is before trying anything test the total pack voltage and if its below 18V then the pack is toast, left that low for a prolonged period means its likely a dead pack, the method used here is the most extreme some one should go and as you quite correctly say LIPO batteries are extremely dangerous and should be handled with care at all times and if you don't know what your doing then don't do it.

    A much safer option would be to hook the pack up to the lipo charger set to 6S via the internal leads and set to 500mah charge rate and bring it up very slowly