P2V autolanding at battery First Level warning

[MikeON]

On my last 2 flights (Jan 15 and 16), the Vision started to land as soon as battery level hit the First Level Warning threshold.
On Jan 15, the threshold was set at 30%. As soon as battery hit 30%, it started descending right where it was. I was able to keep it in the air and steer to a proper landing, but it required a lot of up-throttle.
I then set the First Level threshold to 25% and flew again today (Jan 16). The same thing happened when it hit 25%.
I thought this behavior was supposed to happen at the second level warning. On previous flights, it behaved normally after hitting First Level, just flashed and sounded a warning. The second level is set at 15%
These are the things that changed since previous flights:
-Changed iPhone app to 1.0.32 (I had skipped 1.0.31).
-On Jan 13, I had set S1 bottom position to Manual, flew successfully in Manual mode for about 10 minutes, then set S1 back to Failsafe. It did not try to autoland on Jan 13, but I don't remember whether I had hit either threshold.
-After the Jan 13 flight, I had drained the battery to about 5% by leaving the PV turned on but not flying, then recharged.
Any suggestions would be appreciated.
Mike

 

[stenno]

I had the same thing happen after updating the iphone app. It require throttle up at first battery warning to stay in the air.

I uninstalled the assistant software on my computer downloaded it again and re install the latest firmware onto the PV2

This seemed to fix the issue and after a few test flight it appears the problem is gone, it also fixed another issue I was having with a mismatch firmware update. (this was the initial reason I uninstall the assistant software)

Not sure why it happened but it hasn't happened again yet.

 

[MikeON]

Thanks, stenno.
I had searched all the posts about uncontrolled descent, battery problems, etc., and this appears to be a different issue. I submitted this as a problem report with DJI and will share the reply (if one comes).

 

[Pull_Up]

Any unusual-looking battery figures when you plug into the Assistant? All cells pretty balanced?

 

[MikeON]

All 3 cells indicate 4205 mV at this time.

 

[Pull_Up]

Hmm, we need a scratchy head smiley. I wonder if the low-voltage protection logic that they put in to get over the invalid battery in flight power losses has gone a bit awry? It could be worth re-flashing the latest firmware - I can't think of anything else, though, sorry.

 

[MikeON]

I reinstalled the firmware in the PV and took it flying. First level warning is still set for 25%, second level 15%. This time it flew as expected from 24% down to 19% (klaxon and flashing red LEDs, but normal flight behavior). At 19% on the app, it started descending and required a fair amount of throttle to control. It was only about 15' up when it started descending. App read 18% after landing.
Hooked up to Assistant, and it reads 17% Percent of Charge. Batteries read 3736. 3734, 3732 mV. Been wondering what the app upgrade could possibly have to do with this - maybe it is or was incorrectly reporting the battery % remaining as being higher than the PV thinks it is. But then the question is why would reinstalling the same firmware version fix it, at least partially.
Anyway, I'll not worry about it any more. Will just watch the battery % and keep the PV low and close when the % starts getting near the First Level Warning.

 

[HVMSTORMER]

Mike,

Seems you are not alone, I also have had the same issue yesterday and today, however one flight was on the old App and the second was on the new App version. The flight yesterday started to auto land on first warning set at 30%, I was able to control and apply power however it was defiantly tying to auto land. Went home yesterday, full visual inspection cleaned battery pins and connectors etc and also changed first alert to warn at 25%. Flew this afternoon and sure enough at first warning of 25% now started to auto land again.

Slightly annoyed with myself as I currently have 2 batteries and can't confirm or deny if it was the same battery on both flights, my mistake that would have helped in the elimination process.

My next plan of action I think is to delete the App and then go for a reload and also reload the firmware onto the airframe. I'm assuming that I can just force a new download of the current firmware installed and it will just overweight the old, any advice on this greatly appreciated?

On a positive note I have just had the camera exchanged by RC Geeks (UK), drove down there, really helpful, swapped over the camera (I was more than happy with the airframe) and now I have a great camera which is not blurry on the left hand side. Would recommend their customer support to anyone in the UK.

 

[Pull_Up]

Yep, you can reflash firmware no problem.

 

[MedX172]

Mike,

Seems you are not alone, I also have had the same issue yesterday and today, however one flight was on the old App and the second was on the new App version. The flight yesterday started to auto land on first warning set at 30%, I was able to control and apply power however it was defiantly tying to auto land. Went home yesterday, full visual inspection cleaned battery pins and connectors etc and also changed first alert to warn at 25%. Flew this afternoon and sure enough at first warning of 25% now started to auto land again.

Just curious Mike & HVMSTORMER, are you both operating the P2V in Phantom 2 Vision mode or Naza-M mode?

I've gone below 30% in P2V mode and only got the audible warning on the application and visual led warning on the P2V. I've since reconfigured to Naza-M as I want to experiment with the Home Lock feature. I'll report back my experiences after a flight today when it gets to 30%.

 

[HVMSTORMER]

Thanks Pull up.

I'm still operating in Vision mode, the fault its not critical, as long as you keep an eye on your battery percentage, but it's not doing what's "stated on the tin".

Minor glitch that hopefully a refresh of the firmware will iron out, still a great airframe though.

 

[MikeON]

Just curious Mike & HVMSTORMER, are you both operating the P2V in Phantom 2 Vision mode or Naza-M mode?
%.

I'm running in Naza-M mode. Was in Course Lock on the first autolanding event (at 30%), and IOC off (SW2 top position) on the second event at 25%.

 

[MikeON]

Well, I still have this issue. Flew today to try out the RAW/DNG upgrade. Flew perfectly at 200' and then 500' - took a bunch of pictures. Brought it down to 100', took some more pix. When the battery got close to 30%, I brought it down to about 20' to see what happened. At about 30% the LEDs started to flash red and so did the % indicator in the app. As soon as it hit 25%, it started to autoland and I had to use about 3/4 throttle to keep it airborne and steer to a proper landing. My First Level Warning is set at 25%, second level 15%. Current cell voltages are 3756, 3755, 3753 mV.
I used "Report a Problem" on the DJI website a few days ago - no reply. I'll report here if I do receive a reply or figure it out myself.
Mike

 

[MikeON]

Update on this - yesterday it started to autoland at 37%. I deleted the iPhone app and re-installed it. Tried again today and it started to autoland at 40%. The warnings are set at 25% and 15%. So maybe it was a coincidence that the previous incidents were at the First Level warning percentage. Called DJI and they said I could either send it to them for repair or return it to Atlanta Hobby.
One more thought - maybe it is temperature related - it's 10°F here today.