P4 disconnected in flight, found with battery missing

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My son was flying his P4 on Christmas Day (not a Christmas gift, he's had it about 6 months) and it disconnected mid-flight. It was about 1700 ft away and 150 ft. in the air, and not within line-of-sight, so he waited while trying to reconnect and/or RTH automatically. When it didn't show up, we went looking for it at the last known location.

We weren't ever able to reconnect with it or find it that day, but today I went back to look in the vicinity of LKL and found it. The battery was missing, so I thought it might have come out in-flight since we were very close to it on the day he lost it. The other possibility is it had a hard landing and that jarred the battery out. Although I didn't see it laying close by, it was near a ditch with high weeds and I wasn't going to dig around and find a snake instead!

Just wondered if anyone here has knowledge of a battery coming out mid-flight... seems unlikely, and I've not found any other posts that mention it... but figured I'd ask.
 
Is the Phantom damaged? Were there any nearby obstacles that it could have hit on the way down causing the battery to pop out?

FYI, you could retrieve the internal DAT flight log and view the data using DatCon to see what happened at the end of the flight.
 
Hi WBN, two months ago I was flying on the moors in Yorkshire and the signal to my iPad was breaking up when I was approx 500 mts away so I turned the quad around and flew it back slowly, I hand caught it and saw that the battery was out of it's compartment by a good half inch!!! Thank god they have quite long pins on the connectors, I think flying it back forward stopped the battery from falling our completely otherwise it might have been an expensive repair. The only thing I can think happened is that I did not insert the battery until it clicked into place I now double check that it is secure. Finally I have a RF V16 tracker attached so I would be able to find it in the heather or anywhere else. £35 to safeguard £850 a bargain and I would urge anyone reading this to purchase a tracking device as already there are xmas presents going missing??


Sent from my iPad using PhantomPilots
 
Yeah like msinger said I would look at that flight log. And no I've never heard of a battery coming out during flight.


Sent from my iPhone using PhantomPilots
 
I was flying mine on December 17 and was about 275 feet away and my battery fell out, and destroyed my black Phantom. I returned it to Best Buy and they gave me another. I only had mine for 6 days when this happened. I brought the new one home and refused to fly until I could get DJI Care on it, which didn't happen, so I took it back and traded for a white Phantom 4 and I put the DJI care on it. I have flown over 40 flights so far with no problem. I double check the battery before every flight. That was a sick feeling seeing it go down.
 
Is the Phantom damaged? Were there any nearby obstacles that it could have hit on the way down causing the battery to pop out?

FYI, you could retrieve the internal DAT flight log and view the data using DatCon to see what happened at the end of the flight.

There wasn't any apparent damage. I will see if I can get anything off the onboard log. Have an account on HealthyDrone, but hadn't seen that site. Thanks!
 
Well, I hooked up a USB cable from the computer to the P4, but it seems that it must require being powered on to retrieve any data. Without a battery (we didn't have a spare) that won't be possible just yet.

Here are a few pics of what it looked like when I found it. Unfortunately, I didn't think to take a picture of the spot where I found it. I was actually a bit concerned someone might think I was trespassing and so I didn't want to linger. Took these after I got home with it:

Two props look like they hit mud first, but they weren't broken. There is also a significant splotch of "something" on the top rear above the battery slot.
IMG_1083.jpg


Here's a closer look into the battery slot. There's some discoloration near the bottom left of the back "wall" of the slot, and it appeared that possibly water had accumulated there. We've had light precip here in the Houston area off and on ever since this happened, but nothing hard. This wasn't facing up toward the sky when I found it, but I've no doubt some of the precip probably got into this opening.
IMG_1084.jpg


Here's a closer look at that splotch near the battery slot. The first thing I noticed is it's a different color than the mud on the rotors. It's obvious that the splatter that's on the side wall of the slot couldn't be there if the battery had been in the slot. I'm not sure how tight the seal is, but I'd guess not much could get on the top of the opening either. This looks like something that got there after the battery was gone.
IMG_1090.jpg


Front view... the legs and gimbal seemed to be fine structurally. I have never tried operating it by hand (or even flown the P4), but the gimbal only rotates horizontally about 60-75 degrees. Having watched some of the video my son has shot, I think this is the normal range of motion to avoid getting the struts in the picture (he's not here to ask). The rotation in the vertical plane is closer to 90 degrees.
IMG_1087.jpg


This shows a close-up of the rubber baffle or grommet that sits above the gimbal assembly. A small part of it was hanging down out of the body of the drone, but I was able to tuck it back into the opening and it appears okay.
IMG_1088.jpg


These are all taken with my cell phone, so not the best macro quality pictures. I've cleaned up the drone now and need to decide where to buy a new battery. I'm also thinking about going back out a bit better equipped (ie. with a machete and long stick) to look for the battery that was in it. My son had flown it for about 10 minutes before this happened, so I'm skeptical the battery just fell out mid-air. Just cannot explain why it didn't RTH...
 
I'm guessing when it activated the RTH it must have hit a tree causing the bird to fall, hit the branch knocking out the battery then landed on the floor which may explain how the mud got in there. But it's hard to say with out flight log to look up as it may be a compass error causing it to crash in the tree

Neon Euc
 
Hmmm.... the flight log from the app showed last known altitude as 133 ft. (said 150 in original post from memory). There aren't any trees that tall around here. I just realized, however, that the altitude is above sea level. Take-off altitude is reported as 22 ft, so the true altitude above ground was only 111 ft. That's starting to get closer to the tree tops, but still higher than they would be. Even the tallest trees around here are probably only 70-80 ft tall.

A couple other details about the flight worth mentioning - it had reached the boundary of a "protected" air space whilst flying away from my son's location, which caused it to fly sideways a bit (maybe 50 ft). On the DJI Go app, it shows up as a yellow line around a small general aviation airport. There is a notification reported at take-off which says "The aircraft is in a Warning Zone (Unpaved Airports). Fly with caution here." After he realized he couldn't go forward, it appears he hovered a bit before he activated RTH manually. Digging into the HD flight details a bit more, it reports his altitude when RTH activated as 159.4 ft at 14m 17s flight time. The altitude of last known location is shown as 132.9 ft. at 14m 32s flight time. The only thing I can't find is what the RTH altitude was programmed as in the Go app. Does anyone here know if that is info that is stored in the log?

Here's a screen shot from the HD mapping of the flight log... it doesn't show altitude for each point (at least that I can find), and it doesn't show the yellow line I mentioned from the app. However, for reference it is basically a north-south line just west of where it made the right turn. You can see that there are trees throughout the area, so it is easily conceivable that the bird continued down in altitude after the lost connection.

screen%20shot.jpg
 
I can see two black lines to the next of the green dot. Is there any telephone lines by any chance as they could also have snagged the drone causing it to fall

Neon Euc
 
I can see two black lines to the next of the green dot. Is there any telephone lines by any chance as they could also have snagged the drone causing it to fall

Neon Euc

No, those are shadows of tree trunks. There are no high-tension power lines in the area. Anything like phone lines or local power service lines would be much lower (and there aren't any of those in this area anyway).
 
Is the Phantom damaged? Were there any nearby obstacles that it could have hit on the way down causing the battery to pop out?

FYI, you could retrieve the internal DAT flight log and view the data using DatCon to see what happened at the end of the flight.
If you really want to know what happened, do what msinger said here. :)

Once you get a battery of course.
 
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Went back out and found the battery this afternoon... no way to know if it's going to work yet, but I've got it cleaned up and will test it later.

IMG_1092.jpg


Here's where it and the drone landed...

IMG_1093.jpg


Will post something after I've tried charging the battery... want it to be good and dry before I do.
 
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And those are some pretty tall trees, so easy to see how it could've gotten tangled up and fallen...

IMG_1095.jpg
 
Hooked the battery up to the charger and no joy... was a long shot. Guess we'll have to spend some money to even find out if the P4 will still work. Hoping for a better outcome... and to eventually get a flight log off of it.
 
Well... decided I had nothing to lose so I wiggled the battery around a little (the metal part inside the white plastic housing) and plugged the charger back in. Now it appears to be taking a charge. First light is blinking, I'm monitoring to make sure it doesn't overheat... anyone here have any experience with batteries getting wet?
 
First light was blinking regular pattern (between 1 and 2 flashes per second) for about 10 minutes and third light started blinking a fast pattern. No blinking on the second light. The third light blinks two quick flashes (almost a flicker) then a strong third flash. It's on the same frequency as the first light, always following the blink of the first light. That pattern doesn't match any of the trouble codes from the user manual. I'm guessing that means it's fried... but there isn't a code for that one... :(
 
So DJI is sending us a pre-paid shipping label to return the drone and RC to them for evaluation and repair. Won't know anything more for a couple weeks. Hopefully they can access the flight log and share it with us. I'd really like to see what it did after it disconnected. With how the battery went splat in the mud, I'd say it had to have fallen from a decent height. Hoping this will all be covered under the warranty... we're under 1 year, but over 6 months so some parts may not be covered.

A tad uncomfortable with sending it off not knowing what it did... I have trust issues when the same people who will be deciding whether it was their fault or ours are the ones who control the information flow. I guess that's the only way we'll get to the next step in the process, since I'm not willing to fork over the $115-140 (depending on where it comes from) to get a spare battery just yet. Maybe that's a bit short-sighted... if we expect to replace the drone with another P4 (either free under warranty or at our own expense), then the battery isn't a regretted purchase since we've been discussing getting a spare anyway. Only risk might be putting a brand new battery in a bad aircraft and somehow causing damage to the battery.
 
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Hopefully they can access the flight log and share it with us. I'd really like to see what it did after it disconnected. With how the battery went splat in the mud, I'd say it had to have fallen from a decent height.
From the information you've shared so far, it sound like the remote controller disconnected and the Phantom crashed into a tree when it tried to return home. If you upload your TXT flight log here and post a link back here, I'd be happy to review it and confirm/deny that.
 
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While this may or may not be the case in your instance, batteries DO fall out on occasion. When it does, it's almost always because they haven't been "clicked in" completely (top and bottom). I've never lost a battery but I have had occasions where I put the battery in and it clicked and appeared solid but when I pushed on the bottom of the battery, it clicked again, meaning the first click was only the top tab locking. Every time it happened I was thankful I'd read the forum and seen the advice about adding "verify battery is locked in" to my preflight check list.
 

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