I was working with my Phantom 4 PRO Obsidian and the aircarft simply shuted down while flying with still 20% battery, it was 170m away from me and 50m height and just fell into a river and i couldn't get it back!
I've sent all the possible data and flight logs to DJI, and now they say they couldn't find the root cause for the incident! For me, if they couldn't find the the cause, they should assume the responsability of the incident. How about if i wasn't flying over a river and the drone fell over someone or a car for example?

I wasn't flying in a red area, there was no wind warnings and also no interferences during all the flight, i was flying in an open area and when i was coming back to the home point it just shuted down and fell into the Douro river. The aircraft is still under warranty and now DJI doesn't want to replace me with a new drone, instead, they want to give me a 30% discount for a new aircraft...what a joke!



Does anyone faced the same problem? What should i do? The aircraft is still under warranty and there was no malfunction until it stopped working on his way back to the homepoint controlled by me.

I look forward for some help and comments on this situation!

best regards,
André

Here is the flight log that shows everything: https://www.phantomhelp.com/logviewer/MRTPJK1AH3NEIAM13ZAT/

Can you retrieve the drone?    Log just ends abruply.   It would be good to look at battery connection.                                                                     

ALABAMA Posted at 2-4 09:14
Did you do a CSC?

Alabama, sorry, what is a CSC?

ALABAMA Posted at 2-4 09:14
Did you do a CSC?

Combination Stick Command? No i didn't, i was just flying back normally as usual! :/

André Costa Posted at 2-4 09:15
Alabama, sorry, what is a CSC?

Never mind that.  I didn't realize you did a manual startup.  

ALABAMA Posted at 2-4 09:14
Can you retrieve the drone?    Log just ends abruply.   It would be good to look at battery connection.

Unfortunately no, the drone fall into a river and it was impossible to rescue!

Here is a screenshot of the last thing recorded and where the drone fell!

I would guess there was a complete battery failure.  We have seen this happen to other P4 owners.   Your battery connection  probably shows signs of arching. That would get you a better chance of warranty.

ALABAMA Posted at 2-4 09:26
I would guess there was a complete battery failure.  We have seen this happen to other P4 owners.   Your battery connection  probably shows signs of arching. That would get you a better chance of warranty.

Humm..probably but without the aircraft i can't prove that...it's frustrating trying to prove that it wasn't my fault and seeing that DJI can't figure out what really happened without assume that was a technical problem.

Do you know about other cases? What did DJI do about it?

It seems to have ended just as you hit full forward with the right stick.  I will guess the battery came loose while flying and popped out at that moment.  Sorry for your loss.

Mark The Droner Posted at 2-4 10:25
It seems to have ended just as you hit full forward with the right stick.  I will guess the battery came loose while flying and popped out at that moment.  Sorry for your loss.

i can't figure out what happened...and it seems that DJI cannot find the reason for the incident? Should they assume the incident and replace me a new drone??

Those plastic battery interlocks on the P4 (and probably others) has always been a weak spot in their design.  Cost cutting probably responsible (like many products) for non-robust design.  Poor customer service is why they are not replacing the drone.

Anokadrone Posted at 2-5 05:46
Those plastic battery interlocks on the P4 (and probably others) has always been a weak spot in their design.  Cost cutting probably responsible (like many products) for non-robust design.  Poor customer service is why they are not replacing the drone.

Thats true.."Poor costumer service...".

But i'll keep fighting till DJI replace me with new drone cause if they can't find a reason for the incident they must assume it as a technical error!

Tmahk you for your reply Anokadrone

André Costa Posted at 2-5 03:26
i can't figure out what happened...and it seems that DJI cannot find the reason for the incident? Should they assume the incident and replace me a new drone??

Unfortunately, the first thing you need to do before DJI gives you a replaced drone is to give them the broken drone.  Sorry.  

Mark The Droner Posted at 2-5 11:45
Unfortunately, the first thing you need to do before DJI gives you a replaced drone is to give them the broken drone.  Sorry.

That would be the first thing i wanted to do....but unfortunately the drone fell into a river and sank, it was impossible to rescue!

What can i do?!

André Costa Posted at 2-5 11:52
That would be the first thing i wanted to do....but unfortunately the drone fell into a river and sank, it was impossible to rescue!

What can i do?!

I've been reading these forums for about five years and I don't believe I've heard of anybody who has ever gotten a replacement drone in this kind of situation.  You can read the warranty if you want.  Sorry.  

André Costa Posted at 2-5 06:06
Thats true.."Poor costumer service...".

But i'll keep fighting till DJI replace me with new drone cause if they can't find a reason for the incident they must assume it as a technical error!

But i'll keep fighting till DJI replace me with new drone cause if they can't find a reason for the incident they must assume it as a technical error!

Why should they?
There are a lot of things that DJI can't tell about your flight including  how securely you fitted the battery.
One thing the data does show is in the last line.
It shows you had been hovering and then suddenly gave full stick movements with both joysticks.
Perhaps the battery was not securely latched and the final movement was enough to cause the battery to slip back a little and disconnect?

You can't prove it was a DJI issue, just as DJI can't prove it wasn't.
There's a lack of proof on both sides.

It's unfortunate for you, but you chose to fly in a location where recovery would be impossible.
Because of your location choice, you can't return the drone to DJI.
That's a result of your choice, not DJI's.

Labroides Posted at 2-5 22:47
But i'll keep fighting till DJI replace me with new drone cause if they can't find a reason for the incident they must assume it as a technical error!

Why should they?

"Perhaps the battery was not securely latched and the final movement was enough to cause the battery to slip back a little and disconnect?"

- The battery was securely latched...for sure!

Hey come on...i didn't chose to fly on that location...i was working and filming an hotel that is by the river...so what?! drones are made to fly no matter where! I've always flight over water and nothing happened! What you're saying doesn't make sense!

In four years this was the first time i had a problem...i always fly safe! Drones are part of my work gear...im not a weekend user! ... happens and this wasn't my fault!

André Costa Posted at 2-6 03:41
"Perhaps the battery was not securely latched and the final movement was enough to cause the battery to slip back a little and disconnect?"

- The battery was securely latched...for sure!

The battery was securely latched...for sure!
And you can prove this to DJI?  How?
Maybe it was, maybe it wasn't.

Hey come on...i didn't chose to fly on that location...i was working and filming an hotel that is by the river...so what?!
You didn't?
Then who was on the joysticks, sending your drone out over the river?
It was you and it was your choice.
It's a risk you were prepared to accept.

drones are made to fly no matter where! I've always flight over water and nothing happened! What you're saying doesn't make sense!
It does make sense, perhaps you should read it again.

this wasn't my fault!
But you can't prove it wasn't your fault and you can't prove it was DJI's fault because you flew where you can't recover it.

I think one thing to keep in mind that you as the pilot are responsible for all aspects and risks related to your mission.  You are also responsible for any damage or injury that could result from your actions.  That is why, where I  fly, you would be required to have insurance to fly for hire.  In my policy, such an incident would be covered and I would be reimbursed for the cost of replacing the equipment.  Also, if my actions resulted in someone being injured or damage to someone else's possessions, it would cover up to $1M  in damages.  

Labroides Posted at 2-6 04:49
The battery was securely latched...for sure!
And you can prove this to DJI?  How?
Maybe it was, maybe it wasn't.

looks like you work for DJI!

Thank you for helping me on this case!

André Costa Posted at 2-6 05:01
looks like you work for DJI!

Thank you for helping me on this case!

No .. it looks like I'm just trying to give you a balanced idea of how things work instead of what you want to hear.
I'll always communicate much better than DJI would.

Labroides Posted at 2-6 05:07
No .. it looks like I'm just trying to give you a balanced idea of how things work instead of what you want to hear.
I'll always communicate much better than DJI would.

ok i understand you and i really thank you for your attention Labroides!

This is not about flying over water...this is about a drone that stopped working in the air and in this case, fell into a river and it was impossible to rescue it....i've sent all the info i had to DJI and that's all i have....a flight log, a controller and a hardcase full of accessories!

i am just feeling frustrated with the situation and how DJI is dealing with it!

I've just expected a much better support from DJI...

We're truly sorry knowing about this André. As of the time being, we've sought the attention of the higher-level management for further assistance. Thank you for your patience and understanding, André.

At 20% battery...what was you cell voltage??? I've been flying RC for over 10 years. Lipos don't like to get discharged below I would say 3.6 - 3.65 volts under load (in flight). The reason for that is, if you try to load a lipo at 3.6 volts, under load it will drop to 3.5 and below and it will NOT be able to sustain that voltage and the voltage will drop! sharply!! Google discharge curve for the lipo and you will see that at 3.6 - 3.5 volts the voltage just drops! It can only handle the load well between 4.2 - 3.6 under load. Most likely, what happened was that one of you cells was out of balance and it reached that critical 3.6 or below under load at which point it just dropped in voltage, most likely below 3, dragging the overall voltage of the battery instantly to where the drone had no suitable power to operate. When I fly, I usually don't go below 3.67 volts per cell under load (meaning in flight) and when I land, the voltage bounces back to around 3.74 volts per cell which is where you want it to be. Remember, 3.7 volts a cell is considered to be an empty lipo!!!! If you are draining lipos below 3.6 you are damaging them and they WILL puff in the nearest time you fly.

For all out there! Make sure you lipo cells are balanced before you fly!!!! I.E. If your three of you cells show 4.30 volts and the fourth one is at 4.15 get a new battery!!!

delfin2003 Posted at 2-7 07:20
At 20% battery...what was you cell voltage??? I've been flying RC for over 10 years. Lipos don't like to get discharged below I would say 3.6 - 3.65 volts under load (in flight). The reason for that is, if you try to load a lipo at 3.6 volts, under load it will drop to 3.5 and below and it will NOT be able to sustain that voltage and the voltage will drop! sharply!! Google discharge curve for the lipo and you will see that at 3.6 - 3.5 volts the voltage just drops! It can only handle the load well between 4.2 - 3.6 under load. Most likely, what happened was that one of you cells was out of balance and it reached that critical 3.6 or below under load at which point it just dropped in voltage, most likely below 3, dragging the overall voltage of the battery instantly to where the drone had no suitable power to operate. When I fly, I usually don't go below 3.67 volts per cell under load (meaning in flight) and when I land, the voltage bounces back to around 3.74 volts per cell which is where you want it to be. Remember, 3.7 volts a cell is considered to be an empty lipo!!!! If you are draining lipos below 3.6 you are damaging them and they WILL puff in the nearest time you fly.

Hello delfin2003,

here you can see the log and check the cell voltage!

https://www.phantomhelp.com/logviewer/MRTPJK1AH3NEIAM13ZAT/


thank you for your reply!

André Costa Posted at 2-7 07:24
Hello delfin2003,

here you can see the log and check the cell voltage!

The battery appears to be in good shape, but it has been holding on at around 3.6 under load for a while, in some instances, cells 1 and 4 dropped to around 3.581 according to the log! That is low!!! One of those cells, in my opinion, had to give with an instant and significant voltage drop. Last year, when I bought a P4P pro, i inserted the battery and started playing with it right away. Didn't pay attention to what the battery voltage was or charged the battery before use. A few minutes in, a remote controller started giving me an error message "Battery Cell Error". Keep in mind, the battery was still had some "percentage" according to the DJI app, but one of the cells dropped in voltage significantly, if I remember correctly, it was around 3.3 or 3.2 volts, the rest were around 3.6. Any longer and the drone would have shut down. That battery could no longer balance right. I had to replace it. Now I always pay attention to the cell voltage. I hope you googled "lipo discharge curve" and saw how significant voltage drop is one lipo reaches 3.6 volts

I agree - it's a good idea to know your battery.  Each battery has its own personality and attributes, each behaves differently, and it's a good idea to know your specific battery.   But I don't agree that 3.581 volts in a cell is low.  In fact, that seems pretty wonderful given he was well into the flight.  

The battery shown in the log above is about as healthy as they come.  I would have been very happy to own this battery.  

As far as cells, these DJI batteries, regardless of whatever DJI drone you have, will force the AC to commence auto-land if a cell reaches below 3.3 v, but it's obvious that didn't happen here.  The battery will shut itself off if a cell dips below 3.0 volts.  That didn't happen either.  In a normal flight with a healthy balanced battery, neither of these situations would occur since the 10% total battery critical auto-land would occur before any cell hit its limits.

Cold battery temperature is another no-no which can cause an abrupt shutdown, but 22 mins into the flight, that doesn't seem to be an issue.  The log shows a launch at 16C which is colder than I would launch, but it quickly warmed, and the battery temp was 41C at the end.  

A launch with a partially charged battery is still another no-no.  But the pilot has a fully charged battery - so full he didn't even wait for a GPS lock!  He launched with 100% battery and zero satellites!  This implies he was in a big hurry for some reason - which draws certain implications regarding battery installation I think - given the last line of the log.  

Anyway, I think we can rule out a bad battery and a cold battery.