Battery dropped from 53% to 0% ,almost lost my MA

[Benmoore1234]

I looked at both .txt files. this looks exactly like another user posted.
in all three cases it happened around at the same battery % at almost exactly 8 min flight time.

Sounds just like mine. One guy who commented said he was sure it was a battery issue.im not too sure because I put another battery in and the same happens.
The thing that stands out to me is I was in sport mode just like the other guy. But I can’t really prove anything

 

[Kevjones777]

This is going to turn out to be a software issue else someone has manufactured a pile of faulty batteries. If I were forced to guess I would say that a value of the battery charge percentage is getting messed up somewhere in the code following a battery update. Some value is getting left behind or reporting incorrectly and is getting triggered around 50%.

 

[Benmoore1234]

This is going to turn out to be a software issue else someone has manufactured a pile of faulty batteries. If I were forced to guess I would say that a value of the battery charge percentage is getting messed up somewhere in the code following a battery update. Some value is getting left behind or reporting incorrectly and is getting triggered around 50%.

I tend to agree with a software issue. I’ve emailed DJI this morning in hopes I can get a solution. I will spill the beans once they reply.

 

[Kevjones777]

I tend to agree with a software issue. I’ve emailed DJI this morning in hopes I can get a solution. I will spill the beans once they reply.

I think this might be a work around if the problem is not a faulty battery. It appears that most issues have arisen following the software upgrade on aircraft and batteries. If so try this. Put a fully charge battery in the machine and let it run down with the craft fired up and ready to fly. This will run the battery down anyway. Let it run down to say 20% and recharge it again. It seems like people who recharged the batteries that the problem with the battery went away. It may work.

 

[Fenderman]

This same thing happened to me. It was happened on 1 of my 3 batteries. For me it was a battery firmware issue. I updated the batteries firmware and it has worked fine ever since.

 

[Benmoore1234]

Had my reply from Dji. I think they think it’s two separate issues and not linked. Any how I’ll do as they say and see what happens. I’ll post the reply so people can look.
Hopefully this sorts it and I can move on.


Dear Ben,

Thank you for contacting DJI Technical Support.

We apologize for the experience you have had with your Mavic Air. I understand that there has been an error issues regarding to your battery.

Let us attempt to resolve the error by discharging first your battery by following these steps:

• Place the Intelligent Flight Battery into your aircraft's battery compartment and turn-it on.
• Leave it on until there is less than 8% of power left, until the battery can no longer be turned on.
• Launch the DJI Go App to check battery levels.

After which allow the battery to cool down and recharge them to full charge. Repeat the steps twice then insert it back to the aircraft and power it on.

Launch your DJI Go App and check if the error persist, if there is still an error, kindly screenshot the error message and the battery info, from the DJI GO app (Settings > Aircraft Battery) on your email response.

And about the Signal Errors let us attempt to fix this by following the steps below:

• Please ensure that your firmware us updated, perform a firmware update if prompted by the app.
• Please reset your WiFi Downlink (For Standard & 4K) and check the antenna position of your RC.
• Please Re-link your Aircraft and RC.
• Please calibrate your aircraft's system sensors (IMU and Compass)
• Please attempt to fly the aircraft on a different location free from interference (ie trees, buildings, power grids, airports, communication towers, metallic structures and facilities that emit electromagnetic waves).

Kindly send us a feedback if the process above is a success or send us a screenshot if the issue is still present.
If you have any questions, please feel free to contact DJI Europe Support, Mon-Fri 8:30AM - 5:00PM (UTC+1) via the following three channels:

 

[sar104]

Sounds just like mine. One guy who commented said he was sure it was a battery issue.im not too sure because I put another battery in and the same happens.
The thing that stands out to me is I was in sport mode just like the other guy. But I can’t really prove anything

This does look a lot like the other incident (Battery failure mid flight). The profile of battery drain and then sudden drop in smart battery level to zero is remarkably similar. The two events (yours first) are shown below:





It's still difficult to say whether this is a problem with the aircraft or the battery, since it is the battery (I think) that provides the smart battery level data to the FC.

 

[Benmoore1234]

This does look a lot like the other incident (Battery failure mid flight). The profile of battery drain and then sudden drop in smart battery level to zero is remarkably similar. The two events (yours first) are shown below:

View attachment 34960

View attachment 34961

It's still difficult to say whether this is a problem with the aircraft or the battery, since it is the battery (I think) that provides the smart battery level data to the FC.

I really find it hard to believe it could be a bad battery as it happened to my 2nd battery on my second flight. Unless I’m really unlucky. Dji are treating it like 2 separate faults and offered a solution for both. But I’m sure it’s linked and has something to do with sport mode. Looking at those graphs you posted only makes me believe it more. Like you said they are really similar.

 

[Kevjones777]

I really find it hard to believe it could be a bad battery as it happened to my 2nd battery on my second flight. Unless I’m really unlucky. Dji are treating it like 2 separate faults and offered a solution for both. But I’m sure it’s linked and has something to do with sport mode. Looking at those graphs you posted only makes me believe it more. Like you said they are really similar.

And we know the battery is not actually going to zero,it's just saying it is. My money is on software. If it really went to zero surely the motors would stop there would be no RTH and it would just fall out the sky.

 

[Benmoore1234]

And we know the battery is not actually going to zero,it's just saying it is. My money is on software. If it really went to zero surely the motors would stop there would be no RTH and it would just fall out the sky.

Yes the landing battery was above 50% on both flight logs but not on the iPhone screen and not on the led indicator on the battery , but the rth option wasn’t available because the ma thought it was critical low battery so it auto landed.

 

[Travisimo]

Yes the landing battery was above 50% on both flight logs but not on the iPhone screen and not on the led indicator on the battery , but the rth option wasn’t available because the ma thought it was critical low battery so it auto landed.

Interesting. If it's a software issue, then it's likely a firmware issue within the battery itself and not the aircraft, given that you indicated the battery's led's showed low battery as well. I was leaning towards possibly cold batteries in combination with using sport mode, but a firmware issue within the battery is also a distinct possibility. It's unfortunate that they are treating them like two unrelated incidents when it's pretty clear that it's the same issue on both flights (and with different batteries).

 

[Kevjones777]

That is why I am speculating it's the battery software. Somehow it is not calculating correctly. Unfortunately the so called bad info being given to the CPU can cause a catastrophic event. The weird thing is this is not affecting everyone's MA and everyone's batteries which is puzzling to say the least.

 

[Benmoore1234]

Interesting. If it's a software issue, then it's likely a firmware issue within the battery itself and not the aircraft, given that you indicated the battery's led's showed low battery as well. I was leaning towards possibly cold batteries in combination with using sport mode, but a firmware issue within the battery is also a distinct possibility. It's unfortunate that they are treating them like two unrelated incidents when it's pretty clear that it's the same issue on both flights (and with different batteries).

Is it a possibility that I could reinstall the firmware on the battery? With the assistant. I did all the updates via the app when I first got the bird.

 

[Kevjones777]

Is it a possibility that I could reinstall the firmware on the battery? With the assistant. I did all the updates via the app when I first got the bird.

The only way I can see doing this is to roll back the entire version to 200. Then let it update batteries then reinstall 300. and update batteries again.

 

[Travisimo]

That is why I am speculating it's the battery software. Somehow it is not calculating correctly. Unfortunately the so called bad info being given to the CPU can cause a catastrophic event. The weird thing is this is not affecting everyone's MA and everyone's batteries which is puzzling to say the least.

It could be that most pilots are not experiencing it because it requires a certain set of circumstances that most pilots haven't encountered. For example, I have not had this happen after three dozen flights, but I don't fly in Sport mode (used it one time early on, but have not used it since). It could be a combination of circumstances (cold battery + sports mode + firmware bug) or something like that. Hopefully in time, we can get to the bottom of it so that other pilots can avoid an event like this.

 

[sar104]

And we know the battery is not actually going to zero,it's just saying it is. My money is on software. If it really went to zero surely the motors would stop there would be no RTH and it would just fall out the sky.

I agree it's unlikely to be a simple battery fault, unless there was a bad batch manufactured, but it could be a battery firmware problem.

 

[laurens23]

At the time of the "incident" the battery-full-capacity drops dramatically. Probably the battery percentage drops after some calculating with this new wrong battery-full-capacity. a full, new battery should be around 2375mAh.

it drops from 2260 to 922 in the first flight
it drops from 2287 to 908 in the second flight
there is no data in the txt from the other guys incident.

@Benmoore1234 & @KingPieter can you post the manufacturing dates on the batteries?

 

[sar104]

At the time of the "incident" the battery-full-capacity drops dramatically. Probably the battery percentage drops after some calculating with this new wrong battery-full-capacity. a full, new battery should be around 2375mAh.

it drops from 2260 to 922 in the first flight
it drops from 2287 to 908 in the second flight
there is no data in the txt from the other guys incident.

@Benmoore1234 & @KingPieter can you post the manufacturing dates on the batteries?

Manufactured: Feb 25th, 2018
Printed Serial: 0K4AF2RA3507AH

Manufactured: Feb 28th, 2018 (4 weeks ago)
Printed Serial: 0K4AF2UA3502RH

 

[sar104]

At the time of the "incident" the battery-full-capacity drops dramatically. Probably the battery percentage drops after some calculating with this new wrong battery-full-capacity. a full, new battery should be around 2375mAh.

it drops from 2260 to 922 in the first flight
it drops from 2287 to 908 in the second flight
there is no data in the txt from the other guys incident.

@Benmoore1234 & @KingPieter can you post the manufacturing dates on the batteries?

Good spot. I've no clue what to read into that, but clearly incorrect information from the smart battery.

 

[Benmoore1234]

Good spot. I've no clue what to read into that, but clearly incorrect information from the smart battery.

View attachment 34995

That would make sense and Dji must be thinking the same as they asked me to run the batteries down to 8% and recharge in hope it might recalibrate the batteries.