Phantom 3 Critically low Voltage battery failure brings aircraft down

[mcnetwork]

That's not the right file...

1. Connect your iOS device to your computer by USB.
2. Open iTunes.
3. Select your device in the toolbar. Go to Settings -> Apps.
4. Scroll down to the “File Sharing” section. Select DJI Pilot.
5. In the “DJI Pilot Documents” panel you’ll see some .txt files starting with DJIFlightRecord. Select the ones you want and drag them to an Explorer/Finder window of your choice.

I was using Android but believe I found the correct file, I will load it. Thank you!

 

[mcnetwork]

That's not the right file...

1. Connect your iOS device to your computer by USB.
2. Open iTunes.
3. Select your device in the toolbar. Go to Settings -> Apps.
4. Scroll down to the “File Sharing” section. Select DJI Pilot.
5. In the “DJI Pilot Documents” panel you’ll see some .txt files starting with DJIFlightRecord. Select the ones you want and drag them to an Explorer/Finder window of your choice.

Ok it worked and I have it opened in Google earth and can see my flight path.

 

[CloudsNeverDie]

Thanks for uploading. Since I'm the owner of the site, I can see the flight record in my site logs.

It looks like you took off at 5:38:34PM at about 53% battery.

Everything was fine until, at 5:39:39PM, there was a communication error between the battery and the motherboard (this can happen if e.g. the tiny contacts on the side of the battery aren't making good connection with the Phantom). At that point you had 51% battery left. Because battery communication was lost, the battery reading got stuck at 51%, even though you were still in the air and guzzling up the battery. The battery voltage at that point was 14.659V.

After another ten minutes of flight, at 5:48:56PM, the battery voltage had fallen to 13.469V, which is below the flight controller's critical low battery voltage threshold (presumably 13.5V). Your Phantom went into autoland mode and came down slowly in the water.

I conclude that the actual battery itself was OK and didn't fail. The battery communication error is definitely a fault in either the smart battery circuit or the Phantom itself. I guess one interesting question is, did the app warn you that battery communication had failed?

And yes, this is a great reminder that if the battery percentage stops decreasing, we need to watch the battery voltage carefully - if battery communication is not working, we might have less battery left than the app claims.

 

[Oso]

Awesome info.

 

[Mal_PV2_Ireland]

Could the battery not have been fully seated and the data pins disconnected but the battery contacts were still in place?

 

[bbfpv]

So in conclusion, the assumptions that were made in the original post from June 9th are correct, that the battery was loose.

 

[mcnetwork]

That's not the right file...

1. Connect your iOS device to your computer by USB.
2. Open iTunes.
3. Select your device in the toolbar. Go to Settings -> Apps.
4. Scroll down to the “File Sharing” section. Select DJI Pilot.
5. In the “DJI Pilot Documents” panel you’ll see some .txt files starting with DJIFlightRecord. Select the ones you want and drag them to an Explorer/Finder window of your choice.

I have the

Thanks for uploading. Since I'm the owner of the site, I can see the flight record in my site logs.

It looks like you took off at 5:38:34PM at about 53% battery.

Everything was fine until, at 5:39:39PM, there was a communication error between the battery and the motherboard (this can happen if e.g. the tiny contacts on the side of the battery aren't making good connection with the Phantom). At that point you had 51% battery left. Because battery communication was lost, the battery reading got stuck at 51%, even though you were still in the air and guzzling up the battery. The battery voltage at that point was 14.659V.

After another ten minutes of flight, at 5:48:56PM, the battery voltage had fallen to 13.469V, which is below the flight controller's critical low battery voltage threshold (presumably 13.5V). Your Phantom went into autoland mode and came down slowly in the water.

I conclude that the actual battery itself was OK and didn't fail. The battery communication error is definitely a fault in either the smart battery circuit or the Phantom itself. I guess one interesting question is, did the app warn you that battery communication had failed?

And yes, this is a great reminder that if the battery percentage stops decreasing, we need to watch the battery voltage carefully - if battery communication is not working, we might have less battery left than the app claims.

Wow, thank you for looking into that for me, to answer your question, no I did not get any alerts except for the critical level warning, I had set it to warn me of low level at 35% and critical at 30% I only received the one critical warning that said it was landing. Thank you for your time looking into that. I sure wish I could have at least found the Phantom, the salt water probably would have ruined it anyhow. Thank you for your time, that is a really great app that you wrote! Nice work!

 

[CloudsNeverDie]

Could the battery not have been fully seated and the data pins disconnected but the battery contacts were still in place?

Yes, that's definitely possible. I don't know for sure, but I'd guess that if the battery is 1-2mm out of the bay, the main battery terminals probably still make contact but the data pins disconnect.

We must always remember to push our batteries in firmly until the plastic locking tabs make that satisfying clicking sound.

Hopefully the app flashed a warning that battery communication was lost... if it didn't, that's a bug in the app, I think. The app definitely knew that battery communication was lost because it's in the app logs. So it should have warned the user. Maybe it did, I can't tell.

 

[CloudsNeverDie]

So in conclusion, the assumptions that were made in the original post from June 9th are correct, that the battery was loose.

It does seem that way, yes.

 

[mcnetwork]

Yes, that's definitely possible. I don't know for sure, but I'd guess that if the battery is 1-2mm out of the bay, the main battery terminals probably still make contact but the data pins disconnect.

We must always remember to push our batteries in firmly until the plastic locking tabs make that satisfying clicking sound.

Hopefully the app flashed a warning that battery communication was lost... if it didn't, that's a bug in the app, I think. The app definitely knew that battery communication was lost because it's in the app logs. So it should have warned the user. Maybe it did, I can't tell.

It did NOT display that, if it would have, I would have immediately tried to bring it back or at least over to land not over water then tried to fly back. Thanks again for all the detailed info.

 

[CloudsNeverDie]

I have the

Wow, thank you for looking into that for me, to answer your question, no I did not get any alerts except for the critical level warning, I had set it to warn me of low level at 35% and critical at 30% I only received the one critical warning that said it was landing. Thank you for your time looking into that. I sure wish I could have at least found the Phantom, the salt water probably would have ruined it anyhow. Thank you for your time, that is a really great app that you wrote! Nice work!

You're welcome. Sorry you lost your Phantom.

DJI should replace it for you - this is definitely a bug in the app. There's actually a message in the Android app codebase:

res/values/public.xml: <public type="string" name="warning_battery_error" id="0x7f080062" />
res/values/strings.xml: <string name="warning_battery_error">Battery Communication Error. Fly Carefully</string>

But this message isn't referenced anywhere in the code itself - they forgot to implement the tiny bit of code where they show the error message. If they'd implemented this correctly in the app, you would have seen a warning, and you would have known to fly carefully.

Android DJI Pilot users beware!

 

[Mal_PV2_Ireland]

It really does sound like the battery wasn't fully in and worked it's way out. We've had a thread or 2 about this in the last week

 

[mcnetwork]

Thanks for uploading. Since I'm the owner of the site, I can see the flight record in my site logs.

It looks like you took off at 5:38:34PM at about 53% battery.

Everything was fine until, at 5:39:39PM, there was a communication error between the battery and the motherboard (this can happen if e.g. the tiny contacts on the side of the battery aren't making good connection with the Phantom). At that point you had 51% battery left. Because battery communication was lost, the battery reading got stuck at 51%, even though you were still in the air and guzzling up the battery. The battery voltage at that point was 14.659V.

After another ten minutes of flight, at 5:48:56PM, the battery voltage had fallen to 13.469V, which is below the flight controller's critical low battery voltage threshold (presumably 13.5V). Your Phantom went into autoland mode and came down slowly in the water.

I conclude that the actual battery itself was OK and didn't fail. The battery communication error is definitely a fault in either the smart battery circuit or the Phantom itself. I guess one interesting question is, did the app warn you that battery communication had failed?

And yes, this is a great reminder that if the battery percentage stops decreasing, we need to watch the battery voltage carefully - if battery communication is not working, we might have less battery left than the app claims.

What is strange to me is I was still able to see FPV until the point that it flashed the critical now landing message, that is odd that it lost communication with the battery but the FPV still worked and I guess it did not return home because it was not communicating properly with the battery?

 

[bbfpv]

What is strange to me is I was still able to see FPV until the point that it flashed the critical now landing message, that is odd that it lost communication with the battery but the FPV still worked and I guess it did not return home because it was not communicating properly with the battery?

It didn't return home because RTH doesn't initiate when the battery is critical. It just lands.

 

[Mal_PV2_Ireland]

What is strange to me is I was still able to see FPV until the point that it flashed the critical now landing message, that is odd that it lost communication with the battery but the FPV still worked and I guess it did not return home because it was not communicating properly with the battery?

Maybe if one data pin comes loose you lose battery info and when if the 2nd one comes loose you lose everything and it goes into rth? Just a wild guess

 

[mcnetwork]

You're welcome. Sorry you lost your Phantom.

DJI should replace it for you - this is definitely a bug in the app. There's actually a message in the Android app codebase:

res/values/public.xml: <public type="string" name="warning_battery_error" id="0x7f080062" />
res/values/strings.xml: <string name="warning_battery_error">Battery Communication Error. Fly Carefully</string>

But this message isn't referenced anywhere in the code itself - they forgot to implement the tiny bit of code where they show the error message. If they'd implemented this correctly in the app, you would have seen a warning, and you would have known to fly carefully.

Android DJI Pilot users beware!

I sure hope that they replace it, but from what I have heard, they most likely won't but I will be optimistic and hope. I really appreciate your time on this, thanks again!

 

[jhayman1090]

Please let us know how DJI handles this for you.


Sent from my iPhone using Tapatalk

 

[StevenQX]

Please let us know how DJI handles this for you.


Sent from my iPhone using Tapatalk

I know the answer. 30% discount on new unit...

 

[mcnetwork]

I know the answer. 30% discount on new unit...

I hope they don't just offer me a 30% discount if there is a known bug, I am sure there is a good enough markup on these that it would not hurt them much to send me a new one, I still have a remote!

 

[eseckinger]

I'm not buying all these battery not seated posts based on my experiences with a new battery yesterday. More than likely a bad cell caused this. Look at my post new battery issues and look at my pics. Look at my before flight pic and after 4 min pic. Gonna start monitoring voltage myself now!