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Howto use battery discharge feature

Discussion in 'Phantom 2 Discussion' started by Spetter, Oct 29, 2014.

  1. Spetter

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    Can anybody tell me how to use the new battery discharge feature? I cannot find this answer anywhere.
     
  2. idevsk

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    I asked DJI support how to use discharge feature

    The auto-discharging feature refers to when the battery is fully charged and not been used for 48h, it would discharge automatically to 40%-50% for better storage maintenance.
     
  3. Away Point

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    48 hours! That's an "extended period"?

    That is going to end up wasting changing cycles/battery lifespan, isn't it?

    What load will the battery use to dissipate stored energy? Simply turn itself on? Dissipating 25 amps of energy has the potential to go very wrong, especially if it's occurring unsupervised. This "feature" sounds scary to me.
     
  4. GerdS

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    It's a very slow discharge with few watts load over several hours, by using the balancer loads. Maybe the battery will heat up for some degrees, but you won't remember it if you don't especially monitor it.

    Regards, Gerd
     
  5. knuckles

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    I hope the changes will end up extending our battery life and solve the issues that many people have reported with short life span and early auto land with batteries
    I store my batteries in fire safe lipo bags inside one of these when I'm not using them
    [​IMG]
     
  6. 4wd

    4wd

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    You can work with this rather than against it and still try to part use the battery anyway, so any discharging is minimal.
    We've all had plans changed and not been able to part use a battery for a few days, running the phantom indoors to drain them seems fraught with possible hazards ;)
     
  7. hunch

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    if i know that i won't be flying for more than ONE day i put them in safe charge (50%)
    lipos don't want to be fully charged or completely empty for a long period of time.
    so 48 hours is not really a bad idea. i've talked to so many people and when asked how do you store
    your battery and when do you put them in store charge most of them look like :?

    and those are the same people who then tell me later: "yeah i just flew my phantom and it came down after 6 minutes"

    well you think?? lipos only have so many charge cycles in their lifetime and if you don't fly in the winter and you left your battery fully charged and then
    you come back in the spring thinking i'll just pop it in and go fly you can forget that and toss that battery away because it is useless at that point.

    know all the aspects of the hobby not just the obvious like turn it on and fly.. :)
     
  8. ianwood

    ianwood Taco Wrangler
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    How exactly does a battery that is not connected to anything discharge itself? That energy needs to go somewhere. Very confusing. And typical of DJI to trumpet a new feature and then not provide any detail about it. They can trumpet all they want but they need to get off their pedestal, come hang out with the riff raff and tell us what's what. Or maybe consider providing real documentation.

    I think it would be much better if you could do a special button press on the battery before connecting it to the charger and it will only charge up to 40%. That would make the most sense. I don't want a situation where I charge a battery and when I'm on a shoot, it happens to be the 48th hour and it starts to discharge itself. Even worse, what if you're on a plane and the battery starts to discharge itself. Not a good idea, DJI.
     
  9. birdheezy

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    My question: i usually charge to 100% after flying and then discharge to 50% for long storage, would it be better to just charge half way to 50% and leave it?
     
  10. Bluegrass

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    I know just enough about batteries to know that you need to put a load on them to discharge them. Perhaps these fancy intelligent batteries have a built in load that can be applied with it's built in computer to discharge it. What I want to know is how does the battery get updated by this new software? Do you have to run the new software with each of your spare batteries installed in the Phantom? It would be nice if DJI provided us with some control over this new auto battery discharge.
     
  11. N017RW

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    I would and do favor the "charge half way to 50%" as this is when balancing occurs. Best to store as balanced as possible I would presume.
     
  12. aristosv

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    Has anyone tried this yet? How can a battery discharge itself without any load?
     
  13. N017RW

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    It depends on the make up of the battery's on-board electronics with regards to it's balancing function.
    With many conventional stand-alone balancers often the cells are switched across a shunt to provide a discharge path.

    Not sure if anyone has rev. engineered the electronics enough to know how DJI is achieving the balance function.
    At least I haven't come across anything.
     
  14. ianwood

    ianwood Taco Wrangler
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    Even with a cross connect, basic physics dictates you can't go from 100% charged on all cells to 50% on all cells without putting that stored energy somewhere in some form be it heat or making a motor move or energizing a light.
     
  15. Loaderbull

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    I believe they have balancing loads inside for the balancing of each of the three cells to keep them equally charged.
     
  16. phantomi

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    The more I read, the more I'll delay the upgrade. I'm fine with the 3.07 for now.
     
  17. GerdS

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    As I wrote before, the battery will use their buit-in balancer loads for discharging what means they might slightly warm up for few degrees during that time period. There is no user control needed for this.
    And yes, you have to run the Assistant software for each of your batteries to update them.

    Regards, Gerd
     
  18. ianwood

    ianwood Taco Wrangler
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    I'll assume that's a typo.

    I hope there is a way to turn this "feature" off. I really don't want my batteries trying to dissipate 2,600mah in the form of heat while I am at 39,000ft. And I really don't want them doing that when I am just about to use them either.
     
  19. Away Point

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    That's exactly what I'm thinking. Sounds potentially dangerous, for an automated procedure.

    Still find it surprising to learn that 48 hours is considered "an extended period."

    Gee, here is an idea. Why not make a charger which can easily accommodate all the variables with a touch of button (20-30 min charge, "storage charge", etc.), and lower the onboard flight weight by putting the "smart" in the charger (not to mention lower battery cost by at least half!). You know, like every other R/C model uses....

    I want to be safe first, fun second, and preserve battery life third. I have not the time nor interest in babysitting Phantom batteries. With the limited/proprietary equipment available, to always charge them half way means two very inconvenient things. One, remembering to remove them from the charger at just the right point, and two, remembering to begin charging an hour or two before the idea of flying strikes to me.
     
  20. SteveMann

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    Take the props off.