Nearly lost my MA due to a quickly dying battery

[JoelP]

I am writing to the forum for some expert help to answer a few questions.

Yesterday I flew a Litchi mission with my MA using a battery that was acquired with my MA 6 months ago. The mission was planned to be 13 minutes in length over 2.2mi, seemingly well within my battery range. Video was started about 1200 ft away from my homepoint. It recorded just under 11 minutes of video from start to end and flew no more than 1.5 minutes from my launch point to the start of video. Part way through this mission it was showing 70% battery and then quickly went to 50%. I pushed the speed up to max on the return leg to be sure to complete the mission, but it very quickly went to 50% battery, then 30% and soon was critically low and landing well away from the programmed end of mission. The drone came down on a reasonable glide path, veering to the left near the very end, coming to rest about 1300 ft from the home point and was at 0% battery at the end. Thanks to the last image sent I was able to pinpoint where it landed between a dirt road and a wire fence.

After recovering the drone I put the dead battery on a charger, but it no longer would charge at all. Given that this flight ran the battery fully down in about 12.5 minutes I expect that this was a battery failure.

1. Is it possible to rehabilitate such a dead battery?

2. Is there any warranty on a relatively new battery?

3. Is there a detailed log of this flight when flying in Litchi to help me better determine exactly what happened and if so how?

4. Is there any way to assess the condition of my other two batteries before risking another untimely landing?

5. Is it possible to switch out of Litchi midflight to DJI Go4 to fly to and from the Litchi mission in sport mode to add speed and save power? Pushing the stick forward in Litchi doesn’t seem to go as fast as sport mode.

Thanks for any help with my questions.

 

[WithTheBirds]

In answer to your questions,

1. Almost never
2. DJI try and get away with 6 months in their written manufacturer warranty so probably no.
3. Yes..... Upload the log from your device (the tablet phone you were running litchi on) to DJI Flight Log Viewer - Phantom Help..... The instructions are there. Post a link yo the flight back in this thread so people can take a look.
4. Yes
5. Yes. You can close litchi and open GO4.

At a guess I would say the battery either wasn't charged fully when you took off and/or perhaps that it had been sitting around a long time between last use and being charged.

 

[JoelP]

Thanks for the quick reply. I will order at least one new battery.

I loaded iTunes in my Windows 10 PC and was able to see that there was a log file folder for Litchi, but so far have had no luck at opening that folder or uploading any CSV file. I click on Save and iTunes seems to freeze.

Is there any easier way to assess battery status than to keep a data log of battery level versus time?

Can Litchi and Go4 be running simultaneously? I would think that if I kill Litchi before launching Go4 that the MA would just return to home.

 

[WithTheBirds]

Thanks for the quick reply. I will order at least one new battery.

I loaded iTunes in my Windows 10 PC and was able to see that there was a log file folder for Litchi, but so far have had no luck at opening that folder or uploading any CSV file. I click on Save and iTunes seems to freeze.

Is there any easier way to assess battery status than to keep a data log of battery level versus time?

Can Litchi and Go4 be running simultaneously? I would think that if I kill Litchi before launching Go4 that the MA would just return to home.

RTH is initiated following loss of connection between the controller and your mavic, not between the controller and display device. Interesting you can’t download the log....

How about your current packs? Had they been left sitting for long enough to drain right down? Unfortunately that is a good way to permanently damage them.

 

[JoelP]

Also the battery was at half charge the day/week before and was charged to full the night before. I rechecked this battery level at the start of the flight, as I always do, then launched the Litchi mission. The compass was already calibrated on an earlier flight in the day, so I only hovered about 20 seconds to establish home point before initiating flight. Given that it will now not charge at all I have to believe that this battery is toast and not a matter of a poorly charged battery.

 

[JoelP]

I used to store the batteries at full charge, but was informed a couple of months ago they store better at half charge so I try to keep it just a hair below half charge now. I never stored them fully discharged and rarely take my batteries below 30% charge.

 

[Meta4]

5. Is it possible to switch out of Litchi midflight to DJI Go4 to fly to and from the Litchi mission in sport mode to add speed and save power? Pushing the stick forward in Litchi doesn’t seem to go as fast as sport mode.

Yes, you could ... but there's no need to.
Just cancel the Litchi mission if you don't want to complete it and fly back just like you would in DJI Go.
You could do that by initiating RTH and then cancelling the RTH to fly home faster manually.
Sport Mode is not your friend if the battery is running low.
It's like driving your car at 120 mph - very fast but it guzzles fuel.

I loaded iTunes in my Windows 10 PC and was able to see that there was a log file folder for Litchi, but so far have had no luck at opening that folder or uploading any CSV file.

Go to DJI Flight Log Viewer - Phantom Help
Follow the instructions there to upload your flight record (txt file) from your phone or tablet.
Come back and post a link to the report it gives you.

Can Litchi and Go4 be running simultaneously? I would think that if I kill Litchi before launching Go4 that the MA would just return to home.

Run one or the other ... but not both together.

The compass was already calibrated on an earlier flight in the day, so I only hovered about 20 seconds to establish home point before initiating flight.

Recalibrating the compass is completely unnecessary, no matter where you are flying.
If the Mavic hovers in place without slowly spiraling, the compass is fine and you won't improve anything by recalibrating.

 

[aokusman]

Once you noticed the battery issue you should have landed.

 

[JoelP]

I recalibrated my compass earlier in the day since I was pretty far from where I flew last and my Go4 required a calibration to fly.

If I can ever get into my log, perhaps I can show how quickly my battery went from very healthy to dead. This was a totally new behavior from my experience. It seems that I was returning to home as this was happening, but I was just too far to simply land. Had I done that I would have lost it for sure where I couldn't have recovered it.

 

[JoelP]

This morning I was successful at downloading my CSV files from my iPhone using iTunes and opened the file that corresponded to this flight, but when I open it in Google Earth Pro it only shows my planned flight, not the actual flight path with error messages or battery indications. Is there another file that I can find that contains this?

I attempted to attach the CSV file for this flight to this post, but the tool says that "the uploaded file does not have an allowed extension." Am I uploading this incorrectly?

 

[Meta4]

I recalibrated my compass earlier in the day since I was pretty far from where I flew last and my Go4 required a calibration to fly.

You can travel 1000 miles and recalibration isn't required.
Even 5000 miles because distance from anywhere makes no difference.
If you thought the app was telling you to recalibrate, it was probably warning you of a magnetic influence nearby and the message says: Move or calibrate the compass.
The correct action is always to move away from what the compass is warning you about.
Recalibrating the compass won't solve the issue at all.

This morning I was successful at downloading my CSV files from my iPhone using iTunes and opened the file that corresponded to this flight, but when I open it in Google Earth Pro it only shows my planned flight, not the actual flight path with error messages or battery indications. Is there another file that I can find that contains this? BTW I believe that the precipitous battery decline happened right after reaching WP5 or perhaps WP6.

Post #7 gives you the answer for this.

 

[Jack Daw]

Bear in mind that shooting video is a tremendous drain on battery life. Probably more so than flying in sport mode. If you’re ever in this situation again, stop shooting video before you try to fly home.

 

[swooshdave]

I used to store the batteries at full charge, but was informed a couple of months ago they store better at half charge so I try to keep it just a hair below half charge now. I never stored them fully discharged and rarely take my batteries below 30% charge.

The batteries will automatically discharge to the proper level for storage after I believe 10 days. Manually attempting to discharge to what you think is the right storage level is not needed.

 

[JoelP]

In reply to Jack Daw— I am not aware of how to stop video mid-mission in Litchi. That is related to my question earlier about how to move from Litchi to Go4
Mid flight. That said, if I had killed video I would have had far less info as to where to locate my drone on the ground away from home point. Even the direction of the shadows were key in knowing exactly where to look. I suppose I could have snapped photos intermittently on the way to the ground.

 

[JoelP]

The batteries will automatically discharge to the proper level for storage after I believe 10 days. Manually attempting to discharge to what you think is the right storage level is not needed.

If this is so then I feel that I did nothing to prematurely age my batteries and that 6 months is far too soon to see total failure.

 

[swooshdave]

In reply to Jack Daw— I am not aware of how to stop video mid-mission in Litchi. That is related to my question earlier about how to move from Litchi to Go4
Mid flight. That said, if I had killed video I would have had far less info as to where to locate my drone on the ground away from home point. Even the direction of the shadows were key in knowing exactly where to look. I suppose I could have snapped photos intermittently on the way to the ground.

I would have left the video running so that at the very least you'd have a visual record of the flight.

 

[swooshdave]

If this is so then I feel that I did nothing to prematurely age my batteries and that 6 months is far too soon to see total failure.

While the batteries are generally pretty reliable they are not, nor ever will be, 100% reliable. That is the risk everyone who relies on battery power to put something in the air. The best solution is redundancy which the Air (or Pro or Phantom) don't offer.

 

[JoelP]

While the batteries are generally pretty reliable they are not, nor ever will be, 100% reliable. That is the risk everyone who relies on battery power to put something in the air. The best solution is redundancy which the Air (or Pro or Phantom) offer.

How does the Air (or others) offer redundancy? It only has one battery.

 

[Jack Daw]

In reply to Jack Daw— I am not aware of how to stop video mid-mission in Litchi. That is related to my question earlier about how to move from Litchi to Go4
Mid flight. That said, if I had killed video I would have had far less info as to where to locate my drone on the ground away from home point. Even the direction of the shadows were key in knowing exactly where to look. I suppose I could have snapped photos intermittently on the way to the ground.

I know Go 4 will mark and store the path of an MA regardless of whether it's recording or not: I used it to locate mine when it made an emergency landing on the roof of a nearby Sears, and it was within a foot or two. I think Litchi does the same by uploading data to Airdata as soon as the flight ends -- wherever it may end -- since that data is stored in the program, not on the aircraft.

I think that you can end a Litchi mission, including its video, by hitting red pause button on your remote, but I'm not entirely sure of that. You may also be able to stop the video without stopping the flight simply by hitting the left side record/pause key on your remote.

 

[Meta4]

In reply to Jack Daw— I am not aware of how to stop video mid-mission in Litchi. That is related to my question earlier about how to move from Litchi to Go4
Mid flight. That said, if I had killed video I would have had far less info as to where to locate my drone on the ground away from home point. Even the direction of the shadows were key in knowing exactly where to look. I suppose I could have snapped photos intermittently on the way to the ground.

Recorded flight data would be much, much more useful than video for locating a lost drone.