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P3 - Slow Down Not So Fast

Discussion in 'Pro/Adv Discussion' started by flyNfrank, Dec 22, 2015.

  1. flyNfrank

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    For those don't know, and the ones like me that don't want to know,....DJI has set all P3's up to not fly as fast. Nor will the Ascend or Descend as fast.

    However, it is not quite as bad as it may sound though. The speed reduction will not be affected until either the Temperature of the battery reaches a set point, or if one of the battery cell's reaches a set point in Volts.

    The boss says this was done by reducing the amount of throttle input.

    It's possible that most may not even notice a change.
     
  2. GadgetGuy

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    Any specifics available? Which firmware update implemented this change?
     
  3. John Locke

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    1.6 was just released today.
     
  4. WetDog

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    Is it possible that you can tell us mere mortals what the provenance of this helpful tidbit is?

    If you have a line to the engineering staff at DJI could you please inform them that a helpful and complete listing of changes won't hurt them or the company, won't take much longer to type and would give warm fuzzies to a lot of users.
     
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  5. flyNfrank

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    Thanks... :sunglasses:
     
  6. alokbhargava

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    Does it mean that range will be reduced now?
     
  7. flyNfrank

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    Actually about 80% of the info I gave has already been posted by DJI publicly. The part not known was details I added. And the details I gave are not that big a deal to most, but that in itself is above most anything we've gotten in the past.

    Btw, I would like to say that this firmware update will save a great deal of owners a lot grief had it never happened. And from what I have seen the person mostly responsible for it even getting looked into was someone called "yorlik". I saw where he put a great deal of time and effort posting facts from research he had been doing. He deserves more credit then he probably even realizes.
     
  8. flyNfrank

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    I wouldn't think so. If anything you would think it would extend range due to less battery drain.
     
  9. alokbhargava

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    You may be right as we do not know the most optimum speed giving the best results.
     
  10. Oso

    Oso

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    When I first read the release notes this morning (US time) mentioning the speed changes, I was thinking that people will go nuts about this with a knee jerk reaction. Now that I have thought about, it does seem to make sense. It seems like better battery management is something that DJI probably should have implemented originally. I can't say I'm surprised that DJI has done this now given their recent warning about cold weather flying plus the soon to arrive big increase in new pilots. As @flyNfrank noted, this is sure to save a ton of grief.

    I would be interested in the temperature thresholds that trigger the noted propulsion changes.
     
  11. flyNfrank

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    Luckily we now have the DatConverter setup to go all with Laup's dashware gauges to possibly chase the info down.

    We almost never get any kind of privileged details in any fashion. I see others from time to time try to spin things off like they've been told privileged info, and I just have to laugh because even if they were kissing the donkey....them boyz in China are not giving any info. It's that companies personality to not share the details.
     
  12. GadgetGuy

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    I am interested in that optimum speed as well. Setting the RTH speed to 10m/sec might imply that they have determined that is the optimal speed. It may not return the bird at the fastest speed, but it will likely fly it as far as possible.
     
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  13. Dirty Bird

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    flynfrank how ya doing you old troublemaker! ;)

    A year ago, as winter approached & temperatures dropped, I immediately noticed a significant impact on my Vision+ battery perfomance. P2 batteries that functioned perfectly @ 60 ° or higher would sound the low battery alarm under max throttle or become depleted much sooner @ 35°. I actually stopped flying during the winter due to my concerns over the battery sensitivity to cold.

    Consider my incident the other day with the emergency landing @ Ft. Carroll. The day before a battery flew for 20 minutes at 65°. The next day the same battery auto-lands after 7 minutes @ 50°, but remains powered on for over an hour after landing. The battery obviously had plenty of power available for the electronics. But it couldn't deliver it fast enough for the demands of the high-current motors.

    The cells in a P2 pack are 10C rated. I assume P3 packs are rated the same? A cell of this discharge rating is durable & adequate for supplying a P2/3 power needs. But a 10C pack likely has a low ceiling above the aircraft's power demands. There isn't much room to spare. As temperatures fall the cells C-rating drops. My experience indicates the packs are particularly sensitive to temperature. With the large user base, DJI is almost certainly aware of this as well.

    It makes sense, based on my own experiences, to limit power as temperatures fall. In colder weather I usually stay below 3/4 throttle but, as I discovered the other day, that doesn't always guarantee success. Perhaps DJI should consider increasing their packs to a 20C rating? 20C cells are still durable & this increase would provide a much improved extended ceiling of available current over demand.


     
  14. Dirby

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    i noticed the change when i got my p3p on the black friday special sale.
    i noticed it the first time i flew it that it was going slower
     
  15. shockwave199

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    What about all the people who chime in and say the bird flies great in very cold temperatures? I see this question answered all the time. What was so bad to warrant a change.
     
  16. GadgetGuy

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    So what are the triggers?
    What was the temperature?
    What is the numeric individual cell voltage that triggers this?
    Will it still be triggered when using external batteries, which help relieve the internal battery load and stress?
     
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  17. flyNfrank

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    Hey DB as always good to see posting!

    I've been a DJI Product Tester and do a lot of beta testing for some time now. It appears they feel really good about this recent Firmware release. A number of testers from around the globe tested and we all had very positive feedback with all aspects of the P3 using the current 2.4.3 GO app. My testing is only with the P3P using a Android tablet.

    I can see you have yet to get yourself fitted with a P3 and that is not good. You seriously are missing out on a super cool setup with these P3's. They are leap years ahead of what we use to fly around. There is absolutely no comparison. If your reason has anything to do with not being able to afford one right now, you should at least get the P3 Standard or P3 Advanced which is what I should have bought since I never use or have yet to use the 4K in my P3P. At least get into a setup that is currently supported.

    Btw, you might try resetting your battery. I just mentioned in another thread that I just found out we have to take the P3 battery down to 2% before doing a successful reset.
     
  18. Dirty Bird

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    A DJI product tester? How do I get on that list?
    :)

    It just so happens I have a new P3P and a P3A sitting here in the box. Picked them up during the Black Friday sale. I wanted to pickup a spare P3P aircraft only, but it was a much better deal to get a P3A package instead as it included two more batteries, two sets of props, & a spare controller.

    Have yet to fly either as I'm gathering my P3 gear. Need to order a pair of Flytrex units. Don't leave the ground without it! Been devouring all the P3 info I can so I'll be ready to go when the time comes. :cool:


     
  19. flyNfrank

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    That's great!. You must have came across a smokin deal?

    As for the Flytrex units, uh well....things have really changed. So much so you could waste a lot of money. I'll send you a conversation on that subject. A lot of sadness!