Complete power shutdown in flight

[ghostmac]

Long time lurker. First time poster.
So I'm on vacation, flying over the resort that I'm staying at. Get a low battery warning and start bringing my MP back. Wasn't too far away. On my decent, about 40ft off the ground my MP COMPLETELY POWERS OFF
This happen while over the resort pool. Franticly I took at clothed dive into the pool to retrieve it but looking for some info on how to pull logs to find out exactly what happened. I checked and the battery was indeed properly snapped in. Anyone else heard of this or have any advice on how to go about handling this with DJI ?
Thanks guys..

 

[msinger]

Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

 

[ghostmac]

DJI Flight Log Viewer - PhantomHelp.com

Trying to read the flight log on my mobile phone is difficult but looks like it dropped to 4% battery though I don't think that my controller was showing it as being that low. Anything jump out in these logs?

 

[msinger]

Anything jump out in these logs?

Yep. Your battery shut off mid-flight since it was too low to allow the Spark to continue to fly.

FYI, it's a good idea to always start with a fully charged battery. At 40% (the starting charge level for your flight), the battery was nearly depleted before you took off.

 

[Keule]

In addition what @msinger already said, you ignored the RTH warnings at 3:50 min.
At 03:59 the aircraft initiated auto RTH
The aircraft climbed to the pre-set RTH altitude of 200 m
At 04:38 at 20% battery you cancelled RTH and flew in Sport mode manually
You flew manually until 06:51 in sport mode at which the battery was so low that auto landing was initiated by FC
By that time the remaining battery was to low to bring the AC home safe.

Sport mode drains the battery more quickly.

Here your log interpreted by Airdata:

 

[Anthony Viscomi]

Well at least you retrieved it. Now if you have DJI Refresh all will be fine.

 

[sar104]

While you obviously drove the battery too low on that flight, it also appears that there may be a problem with that battery. If you look at the individual cell voltages, number 3 is showing very large deviations towards the end, and its voltage collapses spectacularly:



Those issues are also reported in the AirData analysis. That battery is only reporting 9 charging cycles, so it may be defective.

@msinger - on that topic - I've been meaning to point out that the PhantomHelp txt log converter appears to be misreporting battery cell voltages. It reports all cells as identical voltages (to the reported 4 significant figures) with cell deviation always exactly zero. That's obviously unphysical, and the reported voltages appear to be simply the reported SMART battery voltage divided by the number of cells, rather than the actual reported voltages (shown above) from the log file. That was not previously the case and it used to report correctly, so it looks like something has changed.

 

[msinger]

@msinger - on that topic - I've been meaning to point out that the PhantomHelp txt log converter appears to be misreporting battery cell voltages. It reports all cells as identical voltages (to the reported 4 significant figures) with cell deviation always exactly zero.

That's correct. It has always reported voltages like that for Mavic flight logs.

 

[Irish-apple]

ok please forgive me for this as I seem to be of reading the log incorrectly.
1. he didnt take the warnings given to him twice I think
2. he started a flight on a battery less then half full ??

among other things will DJI still give him a replacement ?

I thought there very strict as in stick to the rules or else

I am not being bad here as I will myself be purchasing a refresh package and this leads me to believe that if I fail to do the right thing im covered ?

confused here

 

[sar104]

That's correct. It has always reported voltages like that for Mavic flight logs.

OK - so it's just an issue with its interpretation of the Mavic logs. That explains why I remembered it working with other logs. It shouldn't be hard to fix though, since the actual data are in the log in a similar format as for the Phantoms.

 

[beachcombing]

ok please forgive me for this as I seem to be of reading the log incorrectly.
1. he didnt take the warnings given to him twice I think
2. he started a flight on a battery less then half full ??

among other things will DJI still give him a replacement ?

I thought there very strict as in stick to the rules or else

I am not being bad here as I will myself be purchasing a refresh package and this leads me to believe that if I fail to do the right thing im covered ?

confused here

DJI Care Refresh (if the OP has it) will provide a replacement regardless as long as the drone is returned.

What "stick to the rules or else" are you referring to? With DJI Care Refresh, it doesn't matter who is "at fault".

 

[Irish-apple]

DJI Care Refresh (if the OP has it) will provide a replacement regardless as long as the drone is returned.

What "stick to the rules or else" are you referring to? With DJI Care Refresh, it doesn't matter who is "at fault".

as stated nothing meant so dont be getting all uptight what I meant to say and maybe should of worded it better.

I thought if the logs showed you ignored a warning as in return to home and you didnt and you then had an accident you defaulted your warranty / dji refresh so if im right what your saying is once you return the drone no matter what the issue your good to go. thats good to know pal thanks for that

 

[ghostmac]

@sar104 thank you very much for interpretating the battery data. Also thanks to others who have chimed in here. You guys are great.
Some more context to my event; I was using this as a test flight post FW upgrade to adjust any forgotten settings. So I was up and down a few times and did start other flights with a full charge. I was planning on taking footage of my pals wedding today but ignoring the warnings and not paying attention cost me dearly.
I'm hoping that since my bird powered down pre-splashdown, circuity may live after a good drying?
Either way, I have a State farm property policy on it and the agent who sold it to me is here at the resort also. I told him what happened and the claim is already in the works. My MP now may live on as a parts backup. We'll see.
Either way thanks again guys for your help with looking at the logs. Awesome community!

 

[Callum]

@sar104 My MP now may live on as a parts backup.

Do they let you keep the old one after a claim? That would be handy.