Drone battery Red indicator at 62% when flying and more strange things...

[cocoon]

Hi droners family,

Today a very strange things happen to my M2P.

I was flying and the drone battery indicator was at 62% in green colours and suddenly change to red colour. ( see attached pic)
Then, I was in sport mode and I was fighting to come back at home at 3KPH, 10 KPH and hopefully I land with 14 % battery.

Is this an issue with the battery? ( only 20 flight, and very well maintained) or from the IMU?

Any idea or similar cases?

Thanks.

 

[sar104]

It's because the battery level had dropped below the smart battery RTH level and it was estimating that the aircraft might not make it back to the home point. You can see the estimate on the horizontal progress bar.

 

[cocoon]

It's because the battery level had dropped below the smart battery RTH level and it was estimating that the aircraft might not make it back to the home point. You can see the estimate on the horizontal progress bar.

thanks for the feedback, and why I was unable to flight more than 10 KM H in sport mode meanwhile I had the speed stick at the max?

 

[Meta4]

thanks for the feedback, and why I was unable to flight more than 10 KM H in sport mode meanwhile I had the speed stick at the max?

The obvious explanation would be that you were flying against a strong wind.
Post your flight data and it might show more information.

 

[cocoon]

The obvious explanation would be that you were flying against a strong wind.
Post your flight data and it might show more information.

umm not sure about that, I have already flew with strong wind and I was always able to come back with a correct aircraft speed. Would it be an IMU error? Where can I export the flight data in order to post it here? thanks

 

[Meta4]

umm not sure about that, I have already flew with strong wind and I was always able to come back with a correct aircraft speed. Would it be an IMU error? Where can I export the flight data in order to post it here? thanks

As I said, that would be the obvious explanation, but if you post your flight data, we can look further into it to see what else might have been happening.
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.

 

[cocoon]

As I said, that would be the obvious explanation, but if you post your flight data, we can look further into it to see what else might have been happening.
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.

Thanks, I use the sky crystal and it seem I have to download a jdk in order to extract the data from the Jar file...

 

[cocoon]

Thanks, I use the sky crystal and it seem I have to download a jdk in order to extract the data from the Jar file...

I mean the log are into a Dat file extension. and the link you sent me says : This log viewer is not able to process DAT flight logs.

 

[Meta4]

I mean the log are into a Dat file extension. and the link you sent me says : This log viewer is not able to process DAT flight logs.

The instructions I posted didn't say anything about a dat files or jdk or jar files.
Just post the .txt file, that's the important one.

 

[gnirtS]

Without the .txt file it looks like a clear case of a very strong wind at a high altitude (150m) hence not moving much even in sport mode.

The red means the drone thinks its going to struggle to get home. Its quite lucky the drone wasnt lost during this flight...

 

[cocoon]

Without the .txt file it looks like a clear case of a very strong wind at a high altitude (150m) hence not moving much even in sport mode.

The red means the drone thinks its going to struggle to get home. Its quite lucky the drone wasnt lost during this flight...

Maybe it was the case at 150 meters high but on the two last pic I have posted I am only 30 meters high and the same thing happen. and then I was flying at 5 meters and I was unable to fly more than 5KMH....I will check if I can upload the text file, Thanks for the feedback.

 

[cocoon]

The instructions I posted didn't say anything about a dat files or jdk or jar files.
Just post the .txt file, that's the important one.

I got it

Here is the txt file :

I have notice the following event :

1m 26.9s > 1.29 : Cell deviation in red>.0.125V (any alert message when I was flying on the dji go 4 app)

6m 9.5s > first RTH warning ( battery 68% charge)

14m 19.5s : -26.2ft / 16 mph / strong wind alert.
So I was flying lower than my take off point which is normal because I was flying from a rooftop.
But they were no strong wind in my rooftop, so how the wind could be stronger at a lower level?
It indicate 16MPH (aprox. 26KPH) and I am 100% sure (according to the real time speed on the dji go 4 app) that the drone was flying below 6MPH sometimes below 3MPH.
How can we explain that?

Thanks for your help

 

[Meta4]

14m 19.5s : -26.2ft / 16 mph / strong wind alert.
So I was flying lower than my take off point which is normal because I was flying from a rooftop.
But they were no strong wind in my rooftop, so how the wind could be stronger at a lower level?
It indicate 16MPH (aprox. 26KPH) and I am 100% sure (according to the real time speed on the dji go 4 app) that the drone was flying below 6MPH sometimes below 3MPH.
How can we explain that?

Your flight data looks like this: DJI Flight Log Viewer - PhantomHelp.com

The first thing I noticed isn't relevant to your query but you have the RTH height set to 500 metres.
That's not a good setting for general flight as it would take about 5 minutes to climb to 500 metres and descend again, potentially draining the battery as well as putting the drone up in very strong winds.

I noticed the re was a significant wind up high early in your flight.
At 7:14 you left the drone to hover (in Sport Mode) at 152 metres and it wasn't able to maintain position.
It was slowly being blown off position.
At 7:50 as you were descending vertically, at around 75 metres, the drone was again drifting slightly off position.

But the part of the flight that is of concern is down low and starts at 9:54 when you swapped from Tripod mode to Sport Mode and gave it full stick towards the south.
Altitude was 22 metres.
The drone pitched >30° and accelerated to 11 m/s in 7 seconds, but at the same time you changed course 20° to the SE, the speed slowed to 6 m/s even though pitch was still 20-30°.

By 10:37 the speed had increased to 12 m/s, still slower than the still air speed of Sport Mode.
From 11:04 - 11:21 the speed was down to 3-4 m/s with tilt at 25-30°, later increasing to 8 m/s and dropping to 2 m/s.
The lower than normal Sport Mode speeds continued until the end of the flight, all the time with tilt angles close to 30°

That the drone was pitching forward at an angle that would normally produce high speed looks a lot like what would be seen if you were flying into a strong headwind.
As you say there was no significant wind at that level, I'm not sure what else might have caused this.

I don't have enough time to dig deeper into the data to see what might be hidden there.
Perhaps @sar104 would like a puzzle to solve?

 

[cocoon]

woo thanks so much for your detailed answer even if the problem is not solve.
about the cell deviation wich occurred at the beginning of the flight, (Cell deviation in red>.0.125V), it doesn"t matter? or it could be something wrong with the battery? Have a good day.

 

[cocoon]

Your flight data looks like this: DJI Flight Log Viewer - PhantomHelp.com

The first thing I noticed isn't relevant to your query but you have the RTH height set to 500 metres.
That's not a good setting for general flight as it would take about 5 minutes to climb to 500 metres and descend again, potentially draining the battery as well as putting the drone up in very strong winds.

I noticed the re was a significant wind up high early in your flight.
At 7:14 you left the drone to hover (in Sport Mode) at 152 metres and it wasn't able to maintain position.
It was slowly being blown off position.
At 7:50 as you were descending vertically, at around 75 metres, the drone was again drifting slightly off position.

But the part of the flight that is of concern is down low and starts at 9:54 when you swapped from Tripod mode to Sport Mode and gave it full stick towards the south.
Altitude was 22 metres.
The drone pitched >30° and accelerated to 11 m/s in 7 seconds, but at the same time you changed course 20° to the SE, the speed slowed to 6 m/s even though pitch was still 20-30°.

By 10:37 the speed had increased to 12 m/s, still slower than the still air speed of Sport Mode.
From 11:04 - 11:21 the speed was down to 3-4 m/s with tilt at 25-30°, later increasing to 8 m/s and dropping to 2 m/s.
The lower than normal Sport Mode speeds continued until the end of the flight, all the time with tilt angles close to 30°

That the drone was pitching forward at an angle that would normally produce high speed looks a lot like what would be seen if you were flying into a strong headwind.
As you say there was no significant wind at that level, I'm not sure what else might have caused this.

I don't have enough time to dig deeper into the data to see what might be hidden there.
Perhaps @sar104 would like a puzzle to solve?

Hello @sar104, hope you are doing well, any idea? thanks

 

[sar104]

Hello @sar104, hope you are doing well, any idea? thanks

I'll take a look.

 

[sar104]

Hello @sar104, hope you are doing well, any idea? thanks

The aircraft achieved specified tilt in sport mode (35°) and approximately top ground speed (20 m/s) at the start of the flight. The low speed on the way back does appear to have been due to high wind, but the data are a bit unusual:



What is unusual is that it occurred at lower height. AirData also calculates a rather remarkable change in wind speed on the way back, with winds gusting over 15 m/s at low level when they were less than 3 m/s earlier on and much higher. Was there an abrupt change in the weather? The only other obvious possibility is an IMU problem - can you retrieve the mobile device DAT file ending FLY060.DAT?

 

[gnirtS]

That the drone was pitching forward at an angle that would normally produce high speed looks a lot like what would be seen if you were flying into a strong headwind.
As you say there was no significant wind at that level, I'm not sure what else might have caused this.

I don't have enough time to dig deeper into the data to see what might be hidden there.
Perhaps @sar104 would like a puzzle to solve?

Possibly incorrect IMU pitch readings?

 

[cocoon]

The aircraft achieved specified tilt in sport mode (35°) and approximately top ground speed (20 m/s) at the start of the flight. The low speed on the way back does appear to have been due to high wind, but the data are a bit unusual:

View attachment 102642

What is unusual is that it occurred at lower height. AirData also calculates a rather remarkable change in wind speed on the way back, with winds gusting over 15 m/s at low level when they were less than 3 m/s earlier on and much higher. Was there an abrupt change in the weather? The only other obvious possibility is an IMU problem - can you retrieve the mobile device DAT file ending FLY060.DAT?

Thanks for time, I appreciate.
Please find attached the dat file.

I was thinking about the IMU too but I don't have any idea how to isolate this problem, possibility.
During my pre flight checking I have notice that Accelerometer ACC1 sensor was orange (good) and not green (excellent) as usual. Could it be relating with the issue?

I have already flown in strong wind situation and was still able to manage the drone (with a correct speed and correct maneuverability).

So, the day of the concern flight was windy with some changes but really far from strong wind I have already flown.

Thanks you.

 

[sar104]

Thanks for time, I appreciate.
Please find attached the dat file.

I was thinking about the IMU too but I don't have any idea how to isolate this problem, possibility.
During my pre flight checking I have notice that Accelerometer ACC1 sensor was orange (good) and not green (excellent) as usual. Could it be relating with the issue?

I have already flown in strong wind situation and was still able to manage the drone (with a correct speed and correct maneuverability).

So, the day of the concern flight was windy with some changes but really far from strong wind I have already flown.

Thanks you.

Okay - the two IMUs agreed pretty much perfectly throughout the flight, so I guess it had to have been unusual wind conditions on the way back.