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P2 Low battery forced landing

Discussion in 'Phantom 2 Help' started by Dale Young, May 15, 2016.

  1. Dale Young

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    A while back, Alot were having their phantom 2s land due to low battery warning, yet their batteries werent actually low. Did anyone figure this problem out. Mine is doing it now. Ive cycled the battery, and even bought a new battery,..same results.
     
  2. Mako79

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    It happens when you max throttle the Phantom for a duration of time. This causes low voltage warnings as the motors chew past its max threshold triggering early-landing warnings. Silly as it sounds, but try not to max the sticks.

    There is a multitude of reasons for this.
    1. battery. 3x2 (6 batteries) configuration to make a 3S (cell) battery. This is bad for balancing for charging as it can mask faults in the battery. They revised this battery to version 2 (PH2-5200 battery) and this didn't fix the problem.
    2. Variations in motors/ESCs - DJI has released a number of variants in the P2 range. This means different motors/ESCs/Firmwares and this can affect the lifting capacity. DJI may have not done enough testing. Eg latest firmware on the older model Phantoms with the 920kv motors and 1.1 ESC's. DJI may of used a V2 or V3 variant (960kv Motors and 2.1ESCs for current firmware testing.
    3. Payload - If you add weight to your phantom, it will affect lift and the heavier it is, the more likely you will see this Voltage warning.

    Makes sense??
     
  3. Dale Young

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    Makes sense. But Mine didnt get any heavier. Ive been flying it the same for 2 yrs. It just started happening all of the sudden. Bought a new battery and problem remained. Ive tried everything that I can think of.
     
  4. Dale Young

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    Forgot to mention that I fully charge battery and climb to 15-20 ft and just hover. It will force land in about 4 mins on a new, fully charged battery.
     
  5. Mako79

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    What firmwares are you running?
    How many cycles on your battery and what numbers are each of the cells showing?
     
  6. Dale Young

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    Im running 2.0. I want to stay with that. I have about 25 cycles on 1 battery a 2 flights on the new battery. It just started doing it.
     
  7. Dale Young

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    The cells at full charge are showing 4.2 each. Its like the firmware in the quad is shutting it down. The green indicators and assistant says it is around 70% when it goes into auto-land.
     
  8. Mako79

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    If nothing has changed, then the only other factor is weather.. Whats the weather like in your neck of the woods? If its cold, place the battery in your pocket before flight.

    And you haven't told me what the cell values are for each of the 3 cells. If there is deviations, early auto land can trigger.
     
  9. Mako79

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    And also note... PH2-5200 battery has a yellow warning label in the box - you need to be on firmwares 3.0 and above if I recall.
     
  10. Dale Young

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    Not a notable change. Ive been flying this since it came out new. I owned one of the 1st p2 w h3-3d. Never had this problem til now.
     
  11. jason

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    There were many problems with the P2 batteries auto landing.with any where from 70% down to 40% of battery life showing even had that problem. When firmware v3.6 came out it had battery update v2.6 and I updated all five of batteries including two of the five that were auto landing with 40% life with only 20 and 25 cycles at the time. Once those had been update (in November of 2014) I no longer had problem the those two and used them up until November of 2015. DJI pulled that battery update shortly afterwards for what ever reason and never replace it.

    Personally I do not go along with this idea DJI smart batteries 3s x 2p cell are poorly balanced as the balancing is taken care of through circuit board within the battery itself.
     
  12. Dale Young

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    Didnt see that. Ive been using the 5400 batteries with the led screen for about 4 mths now with no problems until now. The values of the cells are nearly identical. Usually varying very little. Currently. 3.96. 3.93. 3.95
     
  13. Dale Young

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    I totally agree. A "smart" battery is a really dumb idea. I like to balance my lipos through a real balancing charger. Are you saying that I can update my batteries firmware?
     
  14. jason

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    You may think a smart battery is a dumb idea but lipo chargers do the same **** thing through a circuit board to sense and balance the voltage per cell.
     
  15. Mako79

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    5400?? Your batteries are aftermarket me thinks
     
  16. jason

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    Not true about the warning label .
     
  17. jason

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    Do you ever check current after charging your batteries as the are just as important as the cell voltage.
    New Battery Screenshot.jpg
     
  18. Dale Young

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    They balance differenly. The DJI balances like an old "blinky" balancer. That is NOT a good way to balance a lipo. Dedicated lipo chargers do it better.
     
  19. jason

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    Here's two from a 6000mAh battery.
    6000mAh Battery #8.jpg
    6000mAh Battery #9.jpg
     
  20. Dale Young

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    Yep. I cannot think of a reason that this is happening. It just started out of the blue.