Phantom 3 Critically low Voltage battery failure brings aircraft down

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I took my P3 out to the beach to get some footage of the Gulf Coast of Florida. I had a fully charged battery and calibrated the aircraft got the green flashing go ahead and green Safe to Fly (GPS) on my DJI Pilot App screen, took off and flew up and down the coastline getting some great footage and photos. I continually was monitoring all of my signal levels to ensure a safe flight since I was over water, just off the coast, less than a minute before the failure I had 51% battery, shortly after, just over 10 minutes into the flight an error message popped up on the screen, it had a red triangle with and exclamation point in the center and said Critically low voltage, the aircraft will land now, I hit the return to home button and the controller started beeping and my FPV went out and the Phantom 3 professional never made it back and I tried looking for it but could not find it in the water. Has anyone heard or had anything like this happen? I posted the flight on youtube, I am hoping DJI does the right thing and replaces it. The video can be seen here
. Thanks for any advice.
 

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When it is auto-landing due to critical battery level, you are supposed to be able to keep it airborne and steer it with up-throttle (left stick). See top of page 14 of manual.
This of course depends how far you have to go to a safe landing site before the battery is completely unable to keep it in the air.
I managed to save my P2V from tall trees this way, when the critical battery auto-landing initiated with over 50% battery remaining. The battery was snapped in tight and contacts cleaned. DJI replaced that battery under warranty.
 
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Good Link this is a Must Read. Sorry to hear. After all the calibrations and settings checks, now checks to make sure the battery is good to go half my battery will be gone, just kidding. But this would be nice if the App checks the battery out before a flight and lets you know one of cells is at a Critical Level.
 
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msinger

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When it is auto-landing due to critical battery level, you are supposed to be able to keep it airborne and steer it with up-throttle (left stick).
Correct. The idea is to allow it to be steered to a safe landing area.
 
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But this would be nice if the App checks the battery out before a flight and lets you know one of cells is at a Critical Level.
Checking the cells prior to take off won't reveal very much in regards to cell health. A load is required in order to calculate the cell internal resistance, which is the only way to measure the health of the LiPo. I don't think it would be very hard for DJI to implement this simple calculation into their intelligent battery so that the user can get some warning before the cell voltage drops below the critical level. In order to calculate the internal resistance, all you need to know is the amount of load and the voltage difference with/without a load.
 
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See if you ha e the find my Phantom. Will give you GPS of it last know location at failure time. May be water damaged but some salvageable. No freebies from DJI sorry.
 
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The entire flight was 10m 22s and I had 51% less than a minute before it gave me the critical battery alert so there is no possible way the battery had died, once it gave me that alert I lost FPV and any ability to control the aircraft, it was about 1/4 mile away and I had been watching the screen due to the sun angle I could not see the P3 when the failure occurred. Thank you everyone for all of the information and links, I am going to go through them all. I only had it for a few weeks and never had any issues, I am pretty bummed out because it was a lot of money (for me) and I had captured some great footage, unfortunately I did swim out to try and find it but the current was very strong and I could not locate it. Thanks everyone for your info!

-Mark
 
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Can you get the .TXT and/or .DAT log files? The .TXT log file is on your tablet or phone. Then you can run them through www.djilogs.com.
 
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Can you get the .TXT and/or .DAT log files? The .TXT log file is on your tablet or phone. Then you can run them through www.djilogs.com.
I uploaded and got the following:
Upload successful!

Filename: crash-2015-06-05-20-05-29.txt

Detected Type: Unknown File Type

Available Conversions:
 
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The children song london bridge is falling down will become phantom three is falling down if this issues will go on...compass and battery the weakest components.
 
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The entire flight was 10m 22s and I had 51% less than a minute before it gave me the critical battery alert so there is no possible way the battery had died, once it gave me that alert I lost FPV and any ability to control the aircraft, it was about 1/4 mile away and I had been watching the screen due to the sun angle I could not see the P3 when the failure occurred. Thank you everyone for all of the information and links, I am going to go through them all. I only had it for a few weeks and never had any issues, I am pretty bummed out because it was a lot of money (for me) and I had captured some great footage, unfortunately I did swim out to try and find it but the current was very strong and I could not locate it. Thanks everyone for your info!

-Mark
Unless you saw the cell voltage prior to losing the signal, you cannot rule out the possibility of a battery/cell failure. I believe the battery percentage is simply calculated by measuring the mAh consumed, which would not reveal a bad cell. I'm sure there's a failsafe to land immediately if one cell falls below a critical voltage, even though there appears to be plenty of voltage/capacity left in the remaining cells.

If a LiPo is defective before it is used, it will fail within the first few cycles... Even if it appeared to be working at first, it can still take a few cycles before the issue makes an impact in performance. It's easy to spot if you know what to look for and when. Monitoring the cell voltages while flying and making sure that the voltage difference is minimal across the cells is what everyone should be doing. Simply relying on the battery percentage will not adequately protect you from such a failure.
 
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I uploaded and got the following:
Upload successful!

Filename: crash-2015-06-05-20-05-29.txt

Detected Type: Unknown File Type

Available Conversions:
That's not the right file...

1. Connect your iOS device to your computer by USB.
2. Open iTunes.
3. Select your device in the toolbar. Go to Settings -> Apps.
4. Scroll down to the “File Sharing” section. Select DJI Pilot.
5. In the “DJI Pilot Documents” panel you’ll see some .txt files starting with DJIFlightRecord. Select the ones you want and drag them to an Explorer/Finder window of your choice.
 
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