DroneFlying Posted at 2017-6-20 03:55
That isn't available on the version of Litchi I have / use (1.16.2 on iOS); "Calibrate Compass" is the last setting / action available in the "Aircraft" section and is followed immediately by the "Camera" section. What Litchi version and OS are you using and would you mind providing a screen capture of what the options look like for you? This is the first I can remember hearing of Litchi allowing a user not to log their flights.

This is the android version.

DroneFlying Posted at 2017-6-20 03:55
That isn't available on the version of Litchi I have / use (1.16.2 on iOS); "Calibrate Compass" is the last setting / action available in the "Aircraft" section and is followed immediately by the "Camera" section. What Litchi version and OS are you using and would you mind providing a screen capture of what the options look like for you? This is the first I can remember hearing of Litchi allowing a user not to log their flights.

It's not on mine 1.16.2 I'm iOS also.

Hold on......are we saying if I fly my drone as it was provided to me by DJI.............and it can fly absolutely fine like that, without a phone................that I am not covered by warranty?

That cannot be right.

I appreciate that the issue here is no logs but.............if say for example, as a several month old owner..............have my phone die but want to capture footage regardless, if i do so and something happens my drone (as we are seeing a good deal of lately) and it drops out of the sky into the sea, that is not a case for a warranty claim?

If that is the case, then the RC has to be made to capture more data on its own.

J

Jinjur Posted at 2017-6-20 04:10
Hold on......are we saying if I fly my drone as it was provided to me by DJI.............and it can fly absolutely fine like that, without a phone................that I am not covered by warranty?

That cannot be right.

No that's not what has been said you can fly with just RC if your on .800 you will already be signed in. But apart from limited log in your remote, you will need to recover your aircraft for proper summation on what happened.

Best advice keep your Aircraft close when flying without app and don't fly over water.

DocDNA Posted at 2017-6-20 04:03
This is the android version.

Interesting. I'm surprised that they provide the ability to disable flight logging and even more surprised that they'd only offer it on Android. I guess I can see the appeal of that to some people, but as in this case it does make it more difficult to figure out what happened in a flight that ended badly. Anyway, thanks for providing that.

DocDNA Posted at 2017-6-20 01:22
There's a lot of speculation based on limited info going on here. This was the 17th charge cycle on the battery, and FWIW, there were other long flights included in those cycles.

There's a lot of speculation based on limited info going on here.

There is a lot of speculation because you've been giving us incomplete or misleading information.  If the intention of your post is to seek help, please try to be forthcoming and complete.  

Jinjur Posted at 2017-6-20 04:10
Hold on......are we saying if I fly my drone as it was provided to me by DJI.............and it can fly absolutely fine like that, without a phone................that I am not covered by warranty?

That cannot be right.

it can fly absolutely fine like that, without a phone

Yes, technically you can fly without a mobile device, but realistically how many people do?

That cannot be right.

It is correct; the burden of proof largely rests on the customer's ability to demonstrate that the aircraft crashed / was lost and that it wasn't their fault. DJI will analyze whatever log information is available, but if none could be provided I wouldn't expect they'd just take the customer's word for what happened.

if say for example, as a several month old owner [I] have my phone die but want to capture footage regardless,

Wouldn't it be difficult to capture footage without the FPV provided through a mobile device? And for a waypoint mission you'd again need such a device with software that could initiate it.

if i do so and something happens my drone (as we are seeing a good deal of lately) and it drops out of the sky into the sea, that is not a case for a warranty claim?

That's a valid point: sometimes people will lose their aircraft through no fault of their own due to defects they then can't prove. But DJI's position on this seems reasonable to me, as I certainly wouldn't be willing to replace every damaged / lost aircraft on the honor system if I were in their business. And technically -- at least according to the user manual -- you're supposed to fly within line of sight and not over bodies of water anyway. So if you fly according to the terms DJI defines then there's very little chance of losing the aircraft altogether and a very high probability of having what's needed to prove that a warranty replacement is due.

17 cycles on 2 days... dafuq man. how is that even possible?

DocDNA Posted at 2017-6-20 03:36
Yep. I got the drone on Friday, and dropped it into the water on Sunday afternoon.

Presumably you were charging the battery immediately after using it?

DroneFlying Posted at 2017-6-20 04:35
it can fly absolutely fine like that, without a phone

Yes, technically you can fly without a mobile device, but realistically how many people do? Any that you know of? Do you?

Fair enough. I just wanted to query it.

Sometimes however, especially of late, it seems very much like the T's & C's of ownership, responsibility and warranty seem to be moving.

Litchi save them to your device. If you have an iPhone you need to use iTunes to get the files. Also sign up to Airdata and you can sync the logs from litchi etc. Just need to input your user token from Airdata.

StephenGSY Posted at 2017-6-20 04:57
Litchi save them to your device. If you have an iPhone you need to use iTunes to get the files. Also sign up to Airdata and you can sync the logs from litchi etc. Just need to input your user token from Airdata.

I'm a bit perplexed on how the Litchi log(s) would help the OP in a warranty claim.

Watty2000 Posted at 2017-6-20 04:37
Presumably you were charging the battery immediately after using it?

I waited until the battery was cool to charge. But yes, there was a lot of back to back flying and charging. I was enjoying my new Mavic.

Jinjur Posted at 2017-6-20 04:34
Fair enough. I just wanted to query it.

Sometimes however, especially of late, it seems very much like the T's & C's of ownership, responsibility and warranty seem to be moving.

I think the big takeway from this thread is that (according to DJI support) that the only source of flight logs they will accept is from DJI Go.

I had mistakenly assumed that the controller logs would suffice (they don't). And, it sounds like everyone flying with Litchi would face a similar issue.

DroneFlying Posted at 2017-6-20 04:20
Interesting. I'm surprised that they provide the ability to disable flight logging and even more surprised that they'd only offer it on Android. I guess I can see the appeal of that to some people, but as in this case it does make it more difficult to figure out what happened in a flight that ended badly. Anyway, thanks for providing that.

Ni problem. It is surprising that feature would be different between iOS / Android.

Griffith Posted at 2017-6-20 04:30
There's a lot of speculation based on limited info going on here.

There is a lot of speculation because you've been giving us incomplete or misleading information.  If the intention of your post is to seek help, please try to be forthcoming and complete.

Griffith, I'm not trying to be misleading or hide anything here. I readily admit that flying over water with such a low battery level with nothing but pilot error (idiocy). So, with that in mind, there's no reason for me to try and be misleading.

You asked me to upload the DJI Go logs, but the whole issue here is that I don't have them. On everything else, I've been answering all the other questions to the best of my ability. I can't anticipate every question.

I was mainly trying to encourage people to ask questions first, instead of speculating, as I thought that would be more productive.

DocDNA Posted at 2017-6-20 05:15
I think the big takeway from this thread is that (according to DJI support) that the only source of flight logs they will accept is from DJI Go.

I had mistakenly assumed that the controller logs would suffice (they don't). And, it sounds like everyone flying with Litchi would face a similar issue.

That's not true, everyone flying litchi will have a problem only if they loose there aircraft, exact same thing applies to dji care refresh. No need to panic people.

hallmark007 Posted at 2017-6-20 06:36
That's not true, everyone flying litchi will have a problem only if they loose there aircraft, exact same thing applies to dji care refresh. No need to panic people.

Good point. So, _if_ you lose your aircraft why flying with Litchi you are SOL. So, just as long as you're sure you're never lose your aircraft, then flying with Litchi is fine. I'm sure there are people that would never lose their aircraft, but for anyone flying where that might be a possibility, then flying with Litchi is problematic.

Anyway, hopefully this will give people food for thought. I certainly wish I had known this before I flew, as I believe that a 20% drop on a fairly new battery is not something that should occur on correctly functioning hardware. Unfortunately, given bad planning and bad luck, this contributed to loss of my Mavic, with no recourse with DJI to address the issue.

By the way, in case anyone is still reading this thread, does anyone have the answer to my original question:

"Where is the small print that flying without DJI Go voids the warranty?"

I wasn't able to find anything, but I'm sure someone must have come across it.

DocDNA Posted at 2017-6-20 07:32
Good point. So, _if_ you lose your aircraft why flying with Litchi you are SOL. So, just as long as you're sure you're never lose your aircraft, then flying with Litchi is fine. I'm sure there are people that would never lose their aircraft, but for anyone flying where that might be a possibility, then flying with Litchi is problematic.

Anyway, hopefully this will give people food for thought. I certainly wish I had known this before I flew, as I believe that a 20% drop on a fairly new battery is not something that should occur on correctly functioning hardware. Unfortunately, given bad planning and bad luck, this contributed to loss of my Mavic, with no recourse with DJI to address the issue.

I agree with you and looking at your RC log there is a huge fast drop in battery power and if only you had your aircraft you would have been able to make a good case.
Good luck.

DocDNA Posted at 2017-6-20 07:38
By the way, in case anyone is still reading this thread, does anyone have the answer to my original question:

"Where is the small print that flying without DJI Go voids the warranty?"

It doesn't void the warranty.  I think you meant to ask "If I don't have a flight log and can't prove to DJI what happened to my drone, how do I convince them to replace it?"

I was told by DJI that I caused my crash, on log 11 at the 312 second mark, by pressing the return to home button. However I only have 3 logs and none of them were more then 254 seconds. So needless to say, my logs read different then DJIs. In addition my remote control never worked. So I was flying with the DJI go app. Which also crashed numerous times. Even sent the whole thing to DJI for repair. A month later got everything back with everything still broke. Including the remote control that never worked. I didn't even have the drone for 24 hours. Before everything went to...crap.

I was told by DJI that I caused my crash, on log 11 at the 312 second mark, by pressing the return to home button. However I only have 3 logs and none of them were more then 254 seconds. So needless to say, my logs read different then DJIs. In addition my remote control never worked. So I was flying with the DJI go app. Which also crashed numerous times. Even sent the whole thing to DJI for repair. A month later got everything back with everything still broke. Including the remote control that never worked. I didn't even have the drone for 24 hours. Before everything went to...crap.

Sorry for the double post.

method007 Posted at 2017-6-20 07:54
It doesn't void the warranty.  I think you meant to ask "If I don't have a flight log and can't prove to DJI what happened to my drone, how do I convince them to replace it?"

It does void the warranty. Here is the legal catch all phrase from the warranty.
"DJI warrants that each DJI product that you purchase will be free from material and workmanship defects under normal use during the warranty period"
Under normal use, normal use is as described in the owners manual and the manual gives detailed instructions on the DJI Go app. If litchi were considered normal use it would be covered in the manual.
I used to have a job where I would be the guy telling you it was not covered. And that language was carefully drafted by lawyers. To cover most situations. So while under warranty use only DJI accessories and the DJI app or fly at your own risk.

DocDNA Posted at 2017-6-20 05:37
Griffith, I'm not trying to be misleading or hide anything here. I readily admit that flying over water with such a low battery level with nothing but pilot error (idiocy). So, with that in mind, there's no reason for me to try and be misleading.

You asked me to upload the DJI Go logs, but the whole issue here is that I don't have them. On everything else, I've been answering all the other questions to the best of my ability. I can't anticipate every question.

DocDNA, hope I did not seem too harsh, but it seemed like we're expending a lot of time and effort to pull out information that should have been stated initially.

I found  your battery voltage plot that you obtained from the "RC Black Box" (something I'm not familiar with).  Is there a complete set of data that you could provide so we could ascertain if there is additional information there that may help with your claim?

method007 Posted at 2017-6-20 07:54
It doesn't void the warranty.  I think you meant to ask "If I don't have a flight log and can't prove to DJI what happened to my drone, how do I convince them to replace it?"

No, my original question was accurate. I have flight log data, just not from DJI Go.

fans2e9aa3da Posted at 2017-6-20 10:37
It does void the warranty. Here is the legal catch all phrase from the warranty.
"DJI warrants that each DJI product that you purchase will be free from material and workmanship defects under normal use during the warranty period"
Under normal use, normal use is as described in the owners manual and the manual gives detailed instructions on the DJI Go app. If litchi were considered normal use it would be covered in the manual.

You should check before you post.
If you take a look at number 11, DAMAGE RESULTING FROM THE USE OF THIRD PARTY APP.
Meaning if your crash is caused directly by the app no cover, if your aircraft crashes because of malfunction of the aircraft you are covered....

DJI Care Refresh does not cover the following:
1) Lost or partially lost aircraft, gimbal or accessories.
2) Stolen, forgotten, or abandoned product.
3) Damage caused by flight under unsuitable conditions.
4) Remote controller, battery of Inspire 2, Phantom 4 Pro and Phantom 4 Advanced, and modification accessories.
5) Deliberate losses.
6) Abrasions and shell damage that do not affect the performance of the product.
7) Direct or indirect losses caused by force majeure.
8) Replacement requests for damage incurred outside the period of validity.
9) Extra fees resulting from technical enhancements or performance improvements.
10) Damage resulting from modifications that are not in accordance with manual recommendations, or the use of incompatible batteries and charger.
11) Damage resulting from the use of third party accessories, batteries or software.

hallmark007 Posted at 2017-6-20 12:07
You should check before you post.
If you take a look at number 11, DAMAGE RESULTING FROM THE USE OF THIRD PARTY APP.
Meaning if your crash is caused directly by the app no cover, if your aircraft crashes because of malfunction of the aircraft you are covered....

Now I'm confused...is it a Warranty claim that the OP is making? Your post is referencing DJI Refresh.

aviscomi Posted at 2017-6-20 12:12
Now I'm confused...is it a Warranty claim that the OP is making? Your post is referencing DJI Refresh.

Number 11 applies the same to warranty as refresh.

Griffith Posted at 2017-6-20 10:45
DocDNA, hope I did not seem too harsh, but it seemed like we're expending a lot of time and effort to pull out information that should have been stated initially.

I found  your battery voltage plot that you obtained from the "RC Black Box" (something I'm not familiar with).  Is there a complete set of data that you could provide so we could ascertain if there is additional information there that may help with your claim?

You're not being too harsh, I just wanted to clarify that it wasn't my intent to be "cagey" or misleading. I big part of the problem is that I don't have the normal log data that most people have, which probably make this whole issue self-explanatory.to everyone here, and DJI.

The data I do have was downloaded from the RC using DJI Assistant 2. If you connect the RC (not Mavic) by USB to DJI Assistant, there is a "BlackBox" option in DJI Assistant that allows you to download this data from the RC. I had assumed it was full flight log data similar to the DJI Go app, but now that I've looked at it, that is not the case.

The "complication" on posting this data here is that the RC black box data is encrypted, and cannot be read by the usual tools (DatCon). I took an educated "guess" at the decryption key based on some information I found online (I am deliberately trying to not be too specific here), and was able to decrypt the "fatal.log" file which is actually just plain text after decryption. I then wrote some scripts to extract some of the data into a more usable (CSV) format so that I could plot the graph above.

Because the BlackBox data is encrypted (and I do mean encrypted, not just binary encoded) I'm guessing that DJI does not want end users to be examining this data. I could post the encrypted files, but that's not going to help unless you can "guess" the decryption key like I did. I'm not sure they would be happy about me posting the decrypted files, although in reality, there doesn't appear to be any proprietary information in them.

Anyway, the "fatal.log" has two types of entries relevant to flight behavior: "radio to UAV", which appears to record the the stick positions, button presses, etc. and "LCD to MCU" messages, which records whatever data that was displayed on the LCD. The "raw" values of all the LCD display areas appear to be logged, including:

• Camera EV
• Speed
• Clearance (above ground - as I had vision disabled due to flying water, looks like this is always "255")
• Height (altitude)
• GPS signal "health" (looks like 1-5 scale)
• Distance from home position
• RPM
• Display text (whatever text is displayed in the middle of the LCD)
• Battery level percentage
• Connected status
  

What it does not include is the lat/long position information, presumably as that information is not displayed on the LCD, and this file appears to only contain LCD related information.

Here's a description of what's in the data:

• I started my return trip with 68% battery remaining, and flight, altitude / RPM / speed / battery are all "nominal" as I'm flying home.
• @13:54.969 (elapsed minutes:seconds), the battery level hits 25%, and "LOW BATTERY" is displayed on the LCD.
• Flight continutes normally
• @14:19.009, with a battery level of 22%, and at an altitude of 62 feet, the LCD displays "LANDING" as Mavic goes into landing mode. (FWIW, my critical battery level was set to 10% - presumably something else trigged this - in Litchi, I remember seeing something about a "cell failure" in the battery)
• @14:19.009 - @14:36.169, I'm flighting auto-land with up-stick on the throttle. Altitude increases slowly, RPM in the 6500 range
• @14:36.169, battery level hits 19%
• @14:41.189, battery level drops to 15% (skipping 18%, 17%, and 16%)
• @14:43.209, battery level drops to 12%, I'm currently at around 85 feet altitude (a result of fighting the landing)
• @14:48.289, battery level now 5%, RPMS around 5000, altitude 80 feet
• @14:50.329, battery now 4%, altitude starts decreasing from 80 feet
• @14:51.449, battery 3%, RPM 4500, altitude 65 feet
• @14:54.249, battery 2%, RPM 4000, altitude 25 feet
• @14:54.509, battery 2%, RPM 1800, altitude 20 feet
• @14:54.709, battery 2%, RPM 1700, altitude 11 feet - last telemetry log
• @14:58.129, RC LCD displays "CONNECTING"
  

To me, this seems pretty strong evidence that the craft was working normally until after the battery level started the rapid drop.

hallmark007 Posted at 2017-6-20 12:07
You should check before you post.
If you take a look at number 11, DAMAGE RESULTING FROM THE USE OF THIRD PARTY APP.
Meaning if your crash is caused directly by the app no cover, if your aircraft crashes because of malfunction of the aircraft you are covered....

I wasn't quoting care refresh but the actual warranty. Care refresh is an optional insurance plan.

fans2e9aa3da Posted at 2017-6-20 14:04
I wasn't quoting care refresh but the actual warranty. Care refresh is an optional insurance plan.

Warranty is the same I was looking for FAQ on warranty I have read it before, I have also checked this out with djiken here and sales@dji.com

It's interesting you mention possibly seeing a bad cell message, as that was my theory for such a dip.   Now Li-Ion/Li-Pos do have a farely decent drop-off approaching 5-10% SoC (State of Charge), but that shouldn't be happening at ~20% unless the smart battery tuning/learning was off.  
Since you had 17 cycles, that's unlikely (though I'm unfamiliar with DJIs BMS [Battery Management System], I have design background on others.)  A cell dropping out would certainly present an immediate and rapid decline...  Suddenly the ESCs are running the motor on an effective 2C, needing more from the batteries just to try an maintain RPM/performance.  It would depleat the other cells very quickly.


It would be good to see a regular (good battery) discharge curve to compare normal vs. this case (with a steady load, like low/no-wind hovering).  Anyone have one?  I've just started looking into the data logging through the DJI Assistant 2, and would hope such is in there.  Every other flight controller I've used has had voltage/time monitoring in their log.   I've honestly never run below 30% either (I'm so used do racing drone batt times of 4min or so, thus 18min seems like an eternity!)

Glad I read this, as I was seriously considering litchi, but I'm certainly hesitant now.  Not sure what the reliability bathtub curve looks like on the Mavic Pro, but mine is still relatively new.   Wouldn't want to risk it.

Mr2MkII Posted at 2017-6-20 15:07
It's interesting you mention possibly seeing a bad cell message, as that was my theory for such a dip.   Now Li-Ion/Li-Pos do have a farely decent drop-off approaching 5-10% SoC (State of Charge), but that shouldn't be happening at ~20% unless the smart battery tuning/learning was off.  
Since you had 17 cycles, that's unlikely (though I'm unfamiliar with DJIs BMS , I have design background on others.)  A cell dropping out would certainly present an immediate and rapid decline...  Suddenly the ESCs are running the motor on an effective 2C, needing more from the batteries just to try an maintain RPM/performance.  It would depleat the other cells very quickly.

Finally a voice of reason. I have an EE / embedded software background as well. I don't know much about BMS design, but I'm guessing its mostly a joule counting system, with some sort of correction based on a discharge model built from the previous charge cycle(s) and/or the battery voltage / current during the current cycle. (Which I'd guess is also used to estimate the internal resistance of the cells).

So I think what I saw was the BMS going "oh crap, my percent remaining estimate is starting to diverge from the discharge model. Do i keep pretending that its accurate, or quickly update to a more realistic number?" And it finally decided to tell the truth.

DocDNA Posted at 2017-6-19 13:33
I was flying with the RC and Litchi. Unfortunately, it looks like Litchi didn't log any data. (It saw mention of CSV files, but couldn't find any)

Not that it seemed to make a difference. DJI support told me that no DJI Go means no help if your Mavic goes down. They didn't even ask if I was using another app.

Since update to latest firmware, unfortunately Litchi has exhibited some issues which make me unable to trust it.

Luckily it wasn't so bad as to cause me to lose or crash the aircraft, though if the scenario had been different it might have.

Thank you DocDNA and Mr2MkII for a most excellent discussion.  I, too, have an EE and embedded systems background and am glad to find some like-minded comrades.  I agree it is likely that the battery lost one of the 3 cells, either from failure or "smart" shutdown.  We have seen that in at least one other incident reported here.  It a particular case, the LOG files revealed a sudden battery voltage drop to  7.5 volts, followed by the Mavic "falling out of the sky".  There continued to be power to operate the electronics and telemetry, so interesting data was obtained.

Thanks for the RC Black Box explanation. I was actually not aware that it cached any flight data.

We can only speculate without direct voltage records, but I can not find fault with this hypothesis.  I only wish some more direct evidence was available to help support your position with DJI.

Just to give everyone an update... as the experienced people here seem to agree that my battery should not have exhibited the sudden drop in power, I've put in another support request with DJI.

My expectations for resolution in my favor are not high, but maybe I'll find someone who's willing to look at the RC BlackBox data. I think it does provide pretty strong support for a battery failure vs pilot error / crash / etc.

DocDNA Posted at 2017-6-20 11:38
No, my original question was accurate. I have flight log data, just not from DJI Go.

The word "and" is vital in my posting.  On that same note - what is DJI telling you regarding your battery?

Tombolian Posted at 2017-6-19 08:21
I predict you will be torn up in here because 1) you were flying over water with only 20% battery, 2) you didn't read up sufficiently on your new DJI drone to learn where the 'black box', as you put it, is, and 3) your story has been in these forums before..  Let's see what happens next.

Hi Tom,

Your Perdiction is correct, I read the thread and Doc has assisted in the confrontation by in his own admission of posting  incorrect information (2 DAYS VS 3 DAYS) in my opinion overworking a battery with 17 recharges to a battery in a very short timeframe and further "limited info" along with his negative attitude,

What did he expect DJI to do when he called to tell them he lost his drone because he flew over water on a low battery using a third party program preventing DJI from a proper investigation, ship out another drone?