Battery failure mid flight

KingPieter · Apr 1, 2018

Hello everyone

I was flying my DJI mavic air about an hour ago and expereinced a hart attack due to a battery failure mid air. I was testing out my brand new battery (the official one from DJI) and he failed mid air. The aircraft itself landed in a tree but I was able to recover it.

My question is: "How was this possible?". I was flying in sport mode before I went further and I used sport mode to go further away from me but I don't know if this may influence this issue.

Tnx for all the answers

Former Member · Apr 1, 2018

A few questions:

1. How do you know the battery failed?
2.Was the battery in the drone when you found it?
3. Was the drone still turned on?
4. Did you try to restart the drone after the crash?
5. What was the battery % afterwards?

KingPieter · Apr 1, 2018

1. The aircraft gave a battery error warning and landed automatically, I couldn't cancel it :/ It also started the RTH secuence
2. Yes the battery was just doing fine but the status dropped down to one light instead of 3. When I returned to my home, I waited till the battery cooled down and connected it to my charger and suddenly the status showed 3 bright lights.
3. The lights of the drone were on when I founded him. The compass was discalibrated though.
4. I tried to restart the craft and it seems to have no problems at all. The app was showing an update warning but I checked the firmware in the DJI assistent application and I just needed to update it to the newer version.
5. Before the failure it showed a % of 70. During the crash the app showed nothing like there wasn't a battery. After the crash the battery status was showing one bright light but when I plugged it in, it went up to 3.

sar104 · Apr 1, 2018

KingPieter said:
1. The aircraft gave a battery error warning and landed automatically, I couldn't cancel it :/ It also started the RTH secuence
2. Yes the battery was just doing fine but the status dropped down to one light instead of 3. When I returned to my home, I waited till the battery cooled down and connected it to my charger and suddenly the status showed 3 bright lights.
3. The lights of the drone were on when I founded him. The compass was discalibrated though.
4. I tried to restart the craft and it seems to have no problems at all. The app was showing an update warning but I checked the firmware in the DJI assistent application and I just needed to update it to the newer version.
5. Before the failure it showed a % of 70. During the crash the app showed nothing like there wasn't a battery. After the crash the battery status was showing one bright light but when I plugged it in, it went up to 3.

I suggest that you check and/or post the flight log - that will show what happened in detail.

ac0j · Apr 1, 2018

For sure, post the logs. The experts will find the defective component and we will join together and make DJI pay for their inferior products!

KingPieter · Apr 1, 2018

I've uploaded the log file to mediafire because it was too big for the forum: DJI_ASSISTANT_EXPORT_FILE_2018-04-01_21-20-42.DAT

And yeah they will pay

Can someone explain how I can open these log files to replay the errors?

sar104 · Apr 1, 2018

KingPieter said:
I've uploaded the log file to mediafire because it was too big for the forum: DJI_ASSISTANT_EXPORT_FILE_2018-04-01_21-20-42.DAT

And yeah they will pay Can someone explain how I can open these log files to replay the errors?

Unfortunately that looks like one of the new DAT files that are not readable (yet, hopefully). Can you get the DAT off the mobile device instead - that should be sufficient.

How to retrieve a V3.DAT from the tablet

KingPieter · Apr 1, 2018

I think this one will be the right one

sar104 · Apr 1, 2018

KingPieter said:
I think this one will be the right one

Strange. The smart battery reported status goes to zero percent as you said, but the actual voltages look fine. The only other anomaly in the record is a brief period at 342 s where the reported cell 2 voltage drops to 1.55 V for 0.9 s, while cell 1 climbs to 4.37 V. Looks like a battery problem to me.

KingPieter · Apr 1, 2018

So should I return it to the store and ask for a refund or can the software update be a fix?

sar104 · Apr 1, 2018

KingPieter said:
So should I return it to the store and ask for a refund or can the software update be a fix?

Hard to say. I'm not sure that I would trust that battery though.

KingPieter · Apr 1, 2018

Yeah I'm going to return it and ask for a replacement, the evidence is clear. I can't trust that battery, especially when I'm flying above forests and stuff.

KingPieter · Apr 1, 2018

Anyhow, thanks for your help!

maven4336 · Apr 1, 2018

KingPieter said:
Hello everyone

I was flying my DJI mavic air about an hour ago and expereinced a hart attack due to a battery failure mid air. I was testing out my brand new battery (the official one from DJI) and he failed mid air. The aircraft itself landed in a tree but I was able to recover it.

My question is: "How was this possible?". I was flying in sport mode before I went further and I used sport mode to go further away from me but I don't know if this may influence this issue.

Tnx for all the answers

Scary, my worst fear

KingPieter · Apr 1, 2018

Yeah DJI should warn their users for this problem xd My heart skipped a beat at that moment I was like no this can't be happening

sar104 · Apr 1, 2018

KingPieter said:
Yeah DJI should warn their users for this problem xd My heart skipped a beat at that moment I was like no this can't be happening

Warn them of what though? Unless there is a known problem with these batteries then there is nothing to warn about.

KingPieter · Apr 1, 2018

Maybe warn them like hey the battery can tell the drone that there isn't any juice left but actually there's plenty xd

sar104 · Apr 1, 2018

KingPieter said:
Maybe warn them like hey the battery can tell the drone that there isn't any juice left but actually there's plenty xd

Right - but that's not how it's supposed to work - that's clearly a fault. There is no point expecting DJI, or any other company, to try to warn consumers of every conceivable way that their products could fail. The list would be endless.

Defiante · Apr 1, 2018

Yes. Electronic devices can malfunction. And when a flying electronic malfunctions we all know the end result

laurens23 · Apr 2, 2018

KingPieter said:
Hello everyone

[...] I was testing out my brand new battery (the official one from DJI) and he failed mid air. [...]

Did you charge the battery before using it the first time? A new battery will be in "storage state" when you get it. The battery percentage drop without the voltage dropping is weird though. Looks like a malfunction regardless of how/if is was charged.

luckily autoland worked