Battery separated from drone prior to crash DJI Air2S

[Tristar500]

I took my Air 2S up for a short test flight following a software update to be sure all was in order before doing a commercial flight the next day.



I took off and went up to 380 feet. I turned the drone 360 degrees to have a look around. I then decided to have a look at a nearby shopping center parking lot. I pointed the drone at the shopping center and moved the left stick up initiating forward movement of the drone. After 3 or 4 seconds The screen went to black and white and displayed a lost connection message. As I looked in the sky for the drone I saw out of the corner of my eye something that appeared to be falling from the sky at a rapid rate. There were birds flying around so I wasn't exactly sure what I saw. I hit the return to home button but nothing. I scanned the sky for the drone but nothing. It was only a few hundred feet at most from my position when things went wrong.

I used the "Find my Drone function but nothing. Eventually, after watching the flight log on the controller I expanded the search after getting a tip that the drone could keep moving in the direction it was traveling after the failure. I found the drone mostly unharmed about 150 feet from its last reported position in some tall weeds. The battery was recovered a short while later 40 feet away in the direction the drone was flying. I looked in this area because it looked as if the battery somehow was ejected and logic told me that the small dense battery would likely continue to travel further than the empty drone due to inherent drag.
The battery is very badly damaged and must have hit the ground at a very high speed.

Has anybody had this happen?

I'd like to report this to dji and see if there is an issue. Naturally, I've grounded the drone until a cause and solution can be determined.

flight log DJI Flight Log Viewer - PhantomHelp.com

 

[slup]

...it looked as if the battery somehow was ejected

That's my guess out from the log also... likely the battery started to swell when you commanded full forward flight & the amp draw increased.

The log doesn't indicate anything abnormal... besides it ends with the drone mid air (& that you started the flight with a battery on only 67%).

Here below the most relevant data from the log (zoomed in to the end of the log).

(Click on the chart to make it larger, the values in the legend is from the very end where the chart marker is at 67,5sec.)

Has anybody had this happen?

Yes... have seen several cases like yours here at the forum before.

 

[Tristar500]

I performed a test post-crash and it is possible to insert the battery enough to power it up but not have the latch click into place. I had never thought to double-check that.
I believe that was the cause of the incident. The battery was not fully and firmly seated into the battery compartment.

The drone is going back to dji to be checked out. The tall grass made for a soft landing and it appears to be in perfect shape but for liability and peace of mind, it's going back to dji.

 

[Cafguy]

I found the drone mostly unharmed about 150 feet from its last reported position in some tall weeds.

Now That's a sign to get a lottery ticket!!

 

[Yorkshire_Pud]

for a short test flight .......... I took off and went up to 380 feet.

Might I suggest that test flights are made at low level and close i.e. under 30ft up and less than a similar distance.

 

[Tristar500]

I understand what you are saying but I was going to be going to 380 feet tomorrow in Atlanta (if in a fly zone) so it was just a routine test from my place in a sparsely populated area where I fly at that altitude frequently.
The only reason for the test flight was to make sure the software on the tablet booted ok as well as the updated DJI Fly software.

 

[Tristar500]

Now That's a sign to get a lottery ticket!!

Right! It's going to DJI for an assessment out of caution. I've got a backup for tomorrow but may decide to leave the drone at home as I don't need any more headaches on my trip. Now. off to buy a lottery ticket

 

[MS Coast]

Presumably, that battery is someplace where there won't be a problem if it spontaneously ignites.

Has anyone had experience with disposing of damaged batteries safely and responsibly? Tossing one into the municipal trash system doesn't seem like a good idea.

 

[Tristar500]

I recovered the battery and it is in really rough shape. Split open and puffy. It hit the ground at whatever the terminal velocity a dji battery has when ejected at 400 feet. Fortunately, the drone, now a battery lighter and with much more drag fared much better and landed in some nice soft tall weeds.

 

[Tristar500]

I recovered the battery and it is in really rough shape. Split open and puffy. It hit the ground at whatever the terminal velocity a dji battery has when ejected at 400 feet. Fortunately, the drone, now a battery lighter and with much more drag fared much better and landed in some nice soft tall weeds.

Oh, and yes, the damaged battery is sitting in a metal pail or water in my backyard till I have the opportunity to take it to the hazmat dropoff location in my city.

 

[samysys]

That's my guess out from the log also... likely the battery started to swell when you commanded full forward flight & the amp draw increased.

The swelling of the battery should be minimum. The weather in Forest Oaks on that day ranged from 14-32C (57-89.6F). The battery temperture was 86.4F (30C) when took off so fits the temperture from obversatory. After 1 min of flight, it slightly increase to 92.5 F (33.6C). The slight increase in temperture is unlikely to cause a sudden swelling or drop in voltage.

Voltage and current were at its peak when taking off and fly its way up. When going forward, the load on the battery shouldn't very high.

Roll/Yaw/Pitch all looks normal the 0.1 second before the adrupt stop so bird strike (or hitting anything) is unlikely.

Most likely, the battery wasn't fully seated on the compartment or the latch was not fully functional. The 40 feet between
their landing locations also indicate the same.

P.S. Any luck with the lottery?

 

[Lets Fly]

moved the left stick up initiating forward movement of the drone.

On my controller left stick up is climbing not forward. Is it different on the AIR2s? Maybe you hit one of the birds.

 

[MavicAir2Marc]

I've had the same thing happen to my Air 2S. Backing up to reframe a shot it lost power. In my case, the battery was swelled just enough to disconnect but stayed in the drone. It actually started to reboot once it hit the ground...not as fortunate as you though, even only about 20 ft up, it came down on pavement so off to Care Refresh it went. I use velcro straps now on my Air 2S just in case to try and keep it connected.

 

[StantonZ]

I recovered the battery and it is in really rough shape. Split open and puffy. It hit the ground at whatever the terminal velocity a dji battery has when ejected at 400 feet. Fortunately, the drone, now a battery lighter and with much more drag fared much better and landed in some nice soft tall weeds.

Would be interested to know the age/how many flights of that battery.

 

[slup]

On my controller left stick up is climbing not forward. Is it different on the AIR2s? Maybe you hit one of the birds.

On most (if not all?) DJI RC's you can choose between 3 stick modes... mode 1 & 3 control pitch (& by that forward/backward flight) with the left stick. The default stick mode 2 (which is used by most I think) have pitch on the right stick.

But he used the right stick & had mode 2 according to the log... so "left" was likely a typo.

And no bird strike or other collision is indicated in the log...

 

[GFields]

Checking for battery swelling or abnormalities is on my pre-flight checklist. I know I may be one of only a handful that uses a check list but it has saved my catastrophes many times over

 

[Dbez1]

“I recovered the battery and it is in really rough shape.”
.

Batteries are not known for their aerodynamic properties lol. I’m glad you recovered the drone and soon you’ll be back in the skies. Thanks for the information though. I’ll make double sure I hear the click sound when inserting the batteries on my 2S

 

[AMann]

I highly recommend these Apex battery straps- There’s a non-slip surface on one side that makes them work really well for preventing batteries from lifting out of a drone and they are handy for other things as well.

 

[sarahb]

Checking for battery swelling or abnormalities is on my pre-flight checklist. I know I may be one of only a handful that uses a check list but it has saved my catastrophes many times over

Good idea. I'll start doing that

 

[Phantomrain.org]

Im thinking bird Strike, as that battery does not look swollen enough to me to point to a swollen battery.

You mention that you were not sure what you were seeing so thinking its possible ?

Phantomrain.org
Gear to fly in the Rain, Land on the water ,an Stay clear of the Birds.