Hi
I recently lost a drone after a controller disconnect. During flight, I didnt seem to get any errors, save for a few GPS errors during flight. After a few minutes of flying, the controller abruptly disconnected, which I believe should have iniated RTH, but the drone never returned home.
I started up the drone after not flying for a few months; I didn't make sure to charge it beforehand, but it would have been fully charged after my last flight and I did not leave the battery inside the drone. The beginning of the logs indicate the battery started at 45%, but quickly dropped to 15% within 5 minutes of flight. Auto-landing was triggered, despite there being a registered RTH location.

The drone is not where the logs point to it having landed. Is it possible my drone's GPS was inaccurate? Why did the battery drop so fast and why was RTH not initiated?

Flight Logs: https://www.phantomhelp.com/LogViewer/9F8758GT4Q2X4Y1KPNPB/#

Why did the battery drop so fast?
Here's the answer:
I started up the drone after not flying for a few months; I didn't make  sure to charge it beforehand, but it would have been fully charged after  my last flight and I did not leave the battery inside the drone. The  beginning of the logs indicate the battery started at 45%, but quickly  dropped to 15% within 5 minutes of flight.
The battery discharges to prolong the life of the battery and the % indicator only gives an accurate reading when you launch with a fully charged battery.
Look at the cell voltage in the Phantomhelp report and you see that they drop close to critical low voltage (3.3 volts) at 48 secs with the drone climbing hard.
At 1:31 there was a warning to confirm the battery's sick status:  Propulsion output has been limited to ensure battery health.
Your battery was much lower than 45% and you always need to start with a fully charged battery.

I didnt seem to get any errors, save for a few GPS errors during flight.

Getting a few GPS Position NoMatch messages is normally not a problem.
But later in the flight you had a lot more than the usual number of these.
Around 1:50 you briefly had this:
Weak GPS signal. Aircraft is in Attitude mode and hovering may be unstable. Fly with caution.
Weak GPS Signal means no GPS signal.
It lasted less than 2 seconds but at 2:53.9, you completely lost all GPS.

why was RTH not initiated?
You continued flying all over the sky in atti mode and without GPS until just after 6 minutes when you lost signal.
Normally that would initiate RTH, but without GPS, the drone is unable to come home as it doesn't know where it is or how to get back.
All it can do is land.
The drone is not where the logs point to it having landed. Is it possible my drone's GPS was inaccurate?
The GPS location data stopped updating when you lost GPS so we have no idea where you flew to in the last 3 minutes of the flight.
If you can work out where you flew to, that's where you need to start searching.


The cause of the loss of GPS isn't clear.

Hello there AndranikC. I am sorry to read and to know what happened to your DJI Drone and thank you for reaching out. Since this unwanted incident happened. It would be best to contact our DJI support team at https://www.dji.com/support for further assistance. We have a team that will do there best check what really happened on that flight and give out the best resolution for this issue. If the said drone is still under the warranty period and it is evaluated as a non-pilot error, the warranty service will be provided. Again, I am sorry for your loss and thank you for your understanding.