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TB47/TB48 Deep Cycling

Discussion in 'Inspire 1 Discussion' started by offtosleep, Jun 17, 2015.

  1. offtosleep

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    I can't seem to find the reference to deep cycle reference anywhere. Can someone point me in the right direction?
     
  2. Skywolf007

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    Of course :) you can read it in manual - page 22
    Its a pretty important thing to do, since if you don't do it the battery electronics might show a different charge percentage

    my personal experience: every 10 flights you should completely discharge the batteries, than immediately charge them to full capacity. You need to discharge the battery to less than 5%. You can do it by flying the I1 - thats the simplest way. When you fly the I1, once it will reach critical 10% battery level it will automatically land. After this you need to discharge the battery to <5%.. which is hard to do if your inspire is not flying but its only turned on.. can take a hell of a time..

    I do it this way: as soon as I get close to 10% I bring the bird close to ground like 1m, and wait for the landing sequence to start. Once it starts landing all you need is to hold the left controller stick up... You need to hold the stick on the same level and it will keep your inspire in air and discharge your battery super fast. Once you have reached 3% just let go of the stick and it will land.
     
  3. offtosleep

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    Thank you sir!
     
  4. chip chipman

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    An excerpt from "Drone Enthusiast"
    Discharge Rates & Level of Discharge
    Earlier I explained what a C rating is. We already know that discharging at a rate beyond the specified C rating will damage a battery. Equally damaging is deep discharging a battery. Most damage to lithium polymer batteries is caused by the user running batteries flat and regardless of the quality of the cells, if you run your battery flat, you will cause irreparable damage and wear your battery out very quickly!

    Leaving an acceptable level of charge in the battery is by far the most significant factor in prolonging battery life and the most common reason for early battery failure is to ignore this advice! Discharging lithium polymer batteries beyond 80% of their capacity can significantly reduce the lifespan of any LiPo battery. Tests have proven that batteries that are only discharged to 50% can be cycled at least 3 times the lifespan of batteries that are regularly flattened. A battery that is flattened every time it’s used, may only last 40-50 cycles, so aim for no more than 80% or certainly a resting voltage of 3.6V or more per cell and you’ll get a lot more from your cells. Sticking to this rule I’ve seen more than 150 cycles from many of my own packs. Yet still, the mythology that abounds leads so many fliers to concentrate on charging rates which have never been the issue, rather than excessive discharge levels. I’ve seen people religiously charge at less than 1C and then go fly a battery completely flat, which is a double blunder! So please make sure you time your flights to leave more than 20% left in your packs and enjoy more cycles!
     
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  5. fei8820

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    erm quick question ..
    after i doing quick discharges it got message on my battery log (history)

    ( Cell undevoltage protections Due to Over Discharges )
    any one can carifly this ? am i doing right ?
     
  6. Skywolf007

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    is it a new battery??? try to charge it the message should disappear..
     
  7. Airwolf13

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    Just exactly where did you get this 'discharge to 5%" nonsense? You are giving dangerous misinformation!!! The reason DJI has the batts SHUT OFF at at 10% is so you don't discharge them too low and ruin them!!
     
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  8. Skywolf007

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    Excuse me?? Can you stop accusing me of giving dangerous misinformation??

    I give you a very good advice. Before you do anything, fly or even turn on the bird: READ THE MANUAL::

    Manual English v1.2 - Page 22:

    [​IMG]
     
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  9. Kilrah

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    Yes it's normal. Cell undervoltage protection kicks in turning off the battery, which is used to know the "fully empty" point.
     
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  10. sirnikolas

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    Follow the manual and you can't go wrong.
     
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  11. Airwolf13

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    OK, I stand corrected. But I will say that there are many articles that state that the artificial lowering the batts to 'total shut down' is bad.
     
  12. fei8820

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    Thanks for the reply :) glad to knw i doing right haha...so do the cycle every 10 times
     
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  13. Kilrah

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    Those "many articles" apply to batteries that don't have a battery management circuitry like DJI batteries have. The shutdown point on those is much higher than where damage appears.
     
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  14. Skywolf007

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    No problem.

    From the start DJI advertised these as Intelligent Batteries.. So they communicate with the device(I1) and the electronics will stop the batteries to be depleted completely.

    Yes batteries do go wrong if they are completely discharged. We are talking about the average drone battery.. not the I1.. The firmware + the chip will not allow the battery to be completely drained, so it will protect the battery..

    Even dead batteries can be "restarted" but you need some hardware and luck to do it :)

    Anyway - remember to deepcycle your batteries every 10 charge. My first battery that came with the Inspire 1 has 40 cycles and already 96% battery health. Although its a fine working battery, I'm thinking about sending it back to dealer. It showed multiple time batter discharge/cell voltage error/over discharge error..
     
  15. Kilrah

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    For the record even if my 3 batteries haven't had many cycles in the past couple of months I'm redoing a calibration on them just based on time... and it's worth it.
    I flew the first battery down to 3% displayed hovering 30cm above ground, landed, then put the battery on discharge. An extra 200mAh or so were drained before the battery shut itself down.
    I did the same for the second and it's still discharging, 1000mAh counted as of now.

    That's a good example of why calibration is required, in this case the app reported a completely empty battery at 3%, yet it still has nearly 25% of its capacity left and counting.

    EDIT: stopped at 1300 ie >25%.
     
    #15 Kilrah, Jun 19, 2015
    Last edited: Jun 19, 2015
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  16. Alexei Karam

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    Yesterday I decided to discharge my battery. Past 10% the inspire will want to auto-land so I had to keep it by force in the air holding the stick up! I kept going till 0% and after it read 0% it stayed in the air for around 2 minutes!!! I kept it at 15 - 20 cm from the ground then it shutdown and dropped to the ground! I wonder if this is what should be actually done or I overdid it and possibly caused damage to the battery! Should I have stopped at 5%?
     
  17. Skywolf007

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    actually the manual says that under 5 % or until it can't be turned on. So it should be just fine.
     
  18. Kilrah

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    It's great for the battery, but I wouldn't want my machine to intentinally fall to the ground unpowered even when just above ground. I.e. I land at 3% or so and finish the discharge process on a common RC charger.
     
  19. Alexei Karam

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    Are you sure it is 100% safe to use an RC charger? I have an icharger 1010B+ I can use. At what rate you discharge ? and what is the min cell voltage you set or do you continue till the battery itself turns itself off? What connector you use to connect it to the charger?
     
  20. Scotflieger

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    It is the extra cable that came with your I1 that connects your battery to the RC charging socket. It is perfectly safe as the RC won't draw a great deal of current.