Help explain what just happened please

jsposito · Apr 5, 2017

Ok, let me just preface this by saying, yes it is my fault.

Nearly no wind today and wanted to do a distance test on P4. Started 100% battery, before I know it my distance is 10,100 feet ( Using those Tozo antenna's)

Here is my issue: the warning light comes on with 40% battery saying it has enough battery to only RTH.I get the option to RTH, I say yes and it starts to return The Phantom battery eventually goes to zero and tries to force land about 200 yards from HP. It would have landed 200 yards away had I taken control of the craft and bring it 100 yards away from HP. IF it takes 60% battery than how could it possible make it home on 40%??

No damage really, the prop guard popped off. And the bird is a little muddy.

AWD · Apr 5, 2017

Nearly no wind on the ground.

What was it at the altitude you were flying?

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msinger · Apr 5, 2017

jsposito said:
IF it takes 60% battery than how could it possible make it home on 40%?

It's not possible to use 100% of the battery, so there really wasn't 40% usable battery remaining.

jsposito · Apr 5, 2017

AWD said:
Nearly no wind on the ground.

What was it at the altitude you were flying?

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300 feet altitude

reddyvv · Apr 5, 2017

Battery is used warming up, preflight checks, hovering, climbing, flight may be meandering, basically lots of reasons. But the most important one would be wind. The bird doesn't how it will be affected by the wind flying back.

jsposito · Apr 5, 2017

msinger said:
It's not possible to use 100% of the battery, so there really wasn't 40% usable battery remaining.

Yes, my friend but as soon as I said yES TO RTH I then looked at the power and it said 40 percent. This battery went to at least 5% and unles my eyes were blurry it eventually said zero. So what am I mssing? Thanks!

jsposito · Apr 5, 2017

reddyvv said:
Battery is used warming up, preflight checks, hovering, climbing, flight may be meandering, basically lots of reasons. But the most important one would be wind. The bird doesn't how it will be affected by the wind flying back.

So, okay let's it launched at 98 percent, and the only thing I did was turn off recording half way through the flight. Should I turn off OA Too? I have to tell you that today the wind was 3mph.

msinger · Apr 5, 2017

jsposito said:
This battery went to at least 5% and unles my eyes were blurry it eventually said zero. So what am I mssing?

Can we check out your flight? Upload it here and post a link back here.

Deleted member 62848 · Apr 5, 2017

jsposito said:
Ok, let me just preface this by saying, yes it is my fault.

Nearly no wind today and wanted to do a distance test on P4. Started 100% battery, before I know it my distance is 10,100 feet ( Using those Tozo antenna's)

Here is my issue: the warning light comes on with 40% battery saying it has enough battery to only RTH.I get the option to RTH, I say yes and it starts to return The Phantom battery eventually goes to zero and tries to force land about 200 yards from HP. It would have landed 200 yards away had I taken control of the craft and bring it 100 yards away from HP. IF it takes 60% battery than how could it possible make it home on 40%??

No damage really, the prop guard popped off. And the bird is a little muddy.

Yeh..hi sounds like some wind up there it found..your flight data will show what changed at 40% batt

jsposito · Apr 5, 2017

msinger said:
Can we check out your flight? Upload it here and post a link back here.

certainly once I get my sd card adapter. So new to this have not even read how upload the FL

msinger · Apr 5, 2017

You won't need an SD card adapter. The TXT flight log is on your mobile device.

tevek · Apr 5, 2017

Looking forward to seeing the log as I suspect that we are going to see wind playing a role in this. I took mine out yesterday and flew to almost the same distance as the OP when I received a low battery RTH warning at 70%. I thought that was a bit conservative as my outbound speed was a steady 50 kmh and being conservative I brought it back. I struggled to hit 25 kmh for the first two klms and had one eyeball glued on the battery level and the other looking out over the forest for any signs of life. Interestingly enough, for the last Klm, it gained speed and I landed with 28%. I had checked the wind speed and direction with my wind app and at the flight height in atti mode, it was a slow drift and thought it was fine to head off. Obviously out at the warning distance, there was some serious wind going on and I gave my drone a little kiss for being so clever.

Deleted member 62848 · Apr 5, 2017

tevek said:
Looking forward to seeing the log as I suspect that we are going to see wind playing a role in this. I took mine out yesterday and flew to almost the same distance as the OP when I received a low battery RTH warning at 70%. I thought that was a bit conservative as my outbound speed was a steady 50 kmh and being conservative I brought it back. I struggled to hit 25 kmh for the first two klms and had one eyeball glued on the battery level and the other looking out over the forest for any signs of life. Interestingly enough, for the last Klm, it gained speed and I landed with 28%. I had checked the wind speed and direction with my wind app and at the flight height in atti mode, it was a slow drift and thought it was fine to head off. Obviously out at the warning distance, there was some serious wind going on and I gave my drone a little kiss for being so clever.

Ha I give mine a pat to when it comes back

jsposito · Apr 5, 2017

tevek said:
Looking forward to seeing the log as I suspect that we are going to see wind playing a role in this. I took mine out yesterday and flew to almost the same distance as the OP when I received a low battery RTH warning at 70%. I thought that was a bit conservative as my outbound speed was a steady 50 kmh and being conservative I brought it back. I struggled to hit 25 kmh for the first two klms and had one eyeball glued on the battery level and the other looking out over the forest for any signs of life. Interestingly enough, for the last Klm, it gained speed and I landed with 28%. I had checked the wind speed and direction with my wind app and at the flight height in atti mode, it was a slow drift and thought it was fine to head off. Obviously out at the warning distance, there was some serious wind going on and I gave my drone a little kiss for being so clever.

So your bird calculated all the variables and therefore gives you a different battery percentage depending on many variables ie., turning, adjusting nose, increase distance and wind?

tevek · Apr 5, 2017

jsposito said:
So your bird calculated all the variables and therefore gives you a different battery percentage depending on many variables ie., turning, adjusting nose, increase distance and wind?

I have no technical answer but clearly something was going on inside the battery as it was calculating power being drawn from the motors which was being impacted on by external variables (wind, distance from HP) and decided it was time to come back. I leave OA off and don't normally waste power filming to try and get a bit more battery life and speed on these trips. If you play back the flight in your app, I think you will see the speed differential on the outgoing and incoming flight. Mine was clearly obvious.

jsposito · Apr 5, 2017

jsposito said:
certainly once I get my sd card adapter. So new to this have not even read how upload the FL

Well, hooked ipad to computer, went into the two folders and only pics and movies.

Then went to DJI go app, highlighted the flight in blue, had the option to export .csv to DJI GO/DOCUMENS. Nut can't find that csv on computer. Other options the usual, album, twitter etc. I see no .txt files in the DJI app.

Deleted member 62848 · Apr 5, 2017

jsposito said:
Well, hooked ipad to computer, went into the two folders and only pics and movies.

Then went to DJI go app, highlighted the flight in blue, had the option to export .csv to DJI GO/DOCUMENS. Nut can't find that csv on computer. Other options the usual, album, twitter etc. I see no .txt files in the DJI app.

Mine are stored in file manager aswell