MPP drops

[radio5991]

Flying today for first time in several months
Batteries charged- everything fine I did notice battery showed 100% till 3:50 in flight
Flew till 30% battery warning then hit RTH
Everything good= Drone back over landing pad 23% battery 23:40 in flight
Drone starts down from 200 feet and sudden battery life drops rapidly
warnings about critically low battery- then drone shuts down and drops from about 75 feet
At 23:50 it's on ground- pretty heavy damage
Any ideas?

 

[slup]

Sounds like a battery cell failure... share your .TXT flight log & we can have a look.

 

[Meta4]

Any ideas?

Your flight data should show a lot more information to help understand the incident.

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.
Or .. just post the txt file here.

 

[radio5991]

Hope this is correct

 

[Meta4]

Hope this is correct

Here's what that data looks like:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

The battery % indication is displaying incorrect information.
At 23:09 you had two cells showing <3.3 volts but the % indicator still shows 25%
3.3 volts should be getting close to zero %.
The flight continued and Autodescent initiated at 23:40.3 with cell voltages <3.0 volts.
Battery power was showing 23%.
Although Autodescent had initiated, the descent did nothing for nearly 7 seconds and then began very, very slowly.
Once it started descending the weak battery was unable to maintain the normal descent speed and the drone accelerated downwards
At 23:54.9 the cell voltages were <2.0 volts and the drone started tumbling in freefall.

 

[boblui]

It seems that the battery is out of calibration. This is the discharge curve of my M2P. The battery % figure hit zero just before the cell voltage started dropping rapidly at about 3.6 V.



This is yours. The % battery shown was 30% while it should be zero.



For smart batteries of this kind, it is really necessary to fully discharge it every few months as instructed by the user manaul to ensure that the BMS ( Battery Management System ) computer inside the battery is updated on the change in battery capacity. In your case it is possible that the BMS was still memorizing the capacity of the battery when it was newer.

The other abnormality is that the battery % figure stayed at 100 in the first 4 minutes. This cannot be true. The BMS seems to be not working properly.

 

[radio5991]

Thanks
I have lost 2 drones to unexplained crashes and this MPP has had 2 near crashes before today. Your explanation sheds some light on a real mystery. Would there be anything to gain by contacting DJI warranty? Batteries and drone less than 4 months old.

 

[boblui]

Thanks
I have lost 2 drones to unexplained crashes and this MPP has had 2 near crashes before today. Your explanation sheds some light on a real mystery. Would there be anything to gain by contacting DJI warranty? Batteries and drone less than 4 months old.

The warranty period for battery is six months and the drone one year. The crash is clearly not caused by pilot error. You should be able to get a replacement free of charge.

 

[radio5991]

could you look at this flight?
Same MPP- I was following a tractor in field when drone just went into full uncontrolled reverse and luckily made a relatively soft landing in some tree branches- same deal with battery 100% showing 4+ minutes into flight

 

[Meta4]

could you look at this flight?
Same MPP- I was following a tractor in field when drone just went into full uncontrolled reverse and luckily made a relatively soft landing in some tree branches- same deal with battery 100% showing 4+ minutes into flight

That data looks like this:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

The battery was also showing false % indications for that flight.
After >4 minutes flying it was still showing 97%.

You were flying the drone south in Active Track videoing a tractor from its right side?
At 3:54.2 you made a full stick input pushing the right stick to the right until3:59.9.
That started the drone moving backwards.
The backwards movement accelerated and continued until you cancelled Active Track at 4:02.6, but It's hard to see why.

 

[radio5991]

the MPP started losing the tractor and I tried to get it to its right to keep up
yes Drone was on tractor's right moving to its right- tractor was traveling south at about 2 mph
That's when everything went wrong
Drone raced backwards at top speed
I normally fly at 160 feet but was lower to watch peanuts being harvested by tractor
Before I could get MPP up it got to trees
Could this be related to battery issues?

 

[Meta4]

Could this be related to battery issues?

The battery would be the last thing that could have affected the flight that way.
The issue starts with your joystick imput but I can't see why it continued after you went hands off.

 

[slup]

...Batteries and drone less than 4 months old.

In that case this battery have been laying around quite a while somewhere ...

 

[radio5991]

My bad
1 battery came with a DJI refurbished MPP in late july
1 battery with this DJI refurbished MPP in September
Receipts on both purchases
In the past I have gotten much more information from this forum than DJI
All I ever got from them was a bill
Any suggestions where to send for repairs?

 

[slup]

My bad
1 battery came with a DJI refurbished MPP in late july
1 battery with this DJI refurbished MPP in September
Receipts on both purchases
In the past I have gotten much more information from this forum than DJI
All I ever got from them was a bill
Any suggestions where to send for repairs?

If you want to pursue a warranty claim ... one way is to submit a online repair request here --> DJI

 

[radio5991]

With DJI it is ALWAYS my fault
They send several emails from different people with different case # for the exact same drone warranty claim
Ask for flight records even after I send them- ask for receipts even after I submit
And then send a bill for NO answers at all
DJI just seems to want to discourage warranty work
At my age this is one of the very few things that I really enjoy doing
I would rather just buy older refurbished models and forget about the warranty
Good repair shops in the US?

 

[DanMan32]

DJI doesn't charge for online support. If they have the AC, they already have the logs stored in the AC.

DJI Drone Services is good. Free estimates and I believe free shipping.