P4 dropped from the sky

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Good day to all.

I've had my P4 (original) since mid 2017. However, I still consider myself to be a beginner - just not enough time flying. Because I'm a beginner, I'm uber careful about everything. Aircraft condition, props, batteries. I'm in Canada and have my TC Basic pilot license and have passed the Advanced exam. But I need to get many more hours flying before I go for my Advanced Certificate flight review.

Yesterday (2020 Jan 25) was a beautiful day in Edmonton - clear blue sky, no clouds, nice sunny day with temperature of about + 4 Celsius. I haven't flown since fall last year, so was just doodling around in the parking lot near my shop. Go up to about 100 feet, go North for a couple of thousand feet, doodle around, so some rooftop inspection, come back. Simple, easy stuff.

Flew about 19 minutes on the first battery and came back when the app said I was down to about 28% battery life remaining. Installed the 2nd battery and had the P4 in a stable hover above the takeoff location. Went into the app to see where to set the home point and was on the General Settings page when I heard the drone stop. I looked up in time to see it tumble from the sky and followed it all the way until it hit the ground right near the takeoff point. The drone is pretty smashed up - one motor mount is fractured and bent and the camera snapped completely off. The battery was lying a foot or so away from the drone and was still ON and showing 4 bars.

My first thought was that somehow the battery wasn't seated properly in the P4. However, I always use both hands / two thumbs to ensure the battery is completely latched into the drone body. Do note the drone was in a stable hover at the time - my attention was on the tablet running the app. My hands were not anywhere near the control sticks on the flight controller.

A physical inspection of the drone shows that the plastic where the battery upper latch snaps in is undamaged but the plastic where the lower latch snaps in is broken. My assumption at this time is the plastic broke when the battery came out of the drone upon impacting the ground.

I've had a quick look at the text log from the flight but I'm a rank amateur at this. I'm hoping that someone with some experience can help me figure out what went wrong so I don't have a similar incident in the future.

I'm attaching several files to this message. Note the most recent files with timestamp 4:38 are the flight that crashed.

I'm not sure what tags I should associate with this post. Perhaps some kind soul can update the tags for me and I'll know better for my subsequent posts.

Other notes: 2nd battery was at room temperature when it was installed in the drone. I was flying in front of my shop, so everything not currently in use was inside the shop where it is nice and warm.

Many thanks!

dwayne
 

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Meta4

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Your flight data shows that you were in a stable hover when the data just stops.
You had a full battery at launch and didn't perform any sudden or severe moves.
There is a warning message of a Battery Error 1.3 seconds before the data ends.
That's not something I've seen before and could be significant but I'm not certain what error it's detected.
A physical inspection of the drone shows that the plastic where the battery upper latch snaps in is undamaged but the plastic where the lower latch snaps in is broken. My assumption at this time is the plastic broke when the battery came out of the drone upon impacting the ground.
Perhaps it is crash damage, but perhaps it isn't.
The plastic in Phantom shells is of variable quality and it's not uncommon for cracks to develop without any crash.
Here's something I noticed when I reversed my P4 pro towards me to catch after a long flight at sea:

The battery would have easily been dislodged and I was lucky it had stayed together for the flight.
The drone had never been crashed, it had never even been landed as I always hand-catch.
 
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ianzone

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Your flight data shows that you were in a stable hover when the data just stops.
You had a full battery at launch and didn't perform any sudden or severe moves.
There is a warning message of a Battery Error 1.3 seconds before the data ends.
That's not something I've seen before and could be significant but I'm not certain what error it's detected.

Perhaps it is crash damage, but perhaps it isn't.
The plastic in Phantom shells is of variable quality and it's not uncommon for cracks to develop without any crash.
Here's something I noticed when I reversed my P4 pro towards me to catch after a long flight at sea:

The battery would have easily been dislodged and I was lucky it had stayed together for the flight.
The drone had never been crashed, it had never even been landed as I always hand-catch.
Now that's a odd place to crack ay,:rolleyes:
 

ianzone

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@DwayneR in app under warnings does it metion anything there,yes did say battery error but cell deviation not enough to cause alert ,,and having it shut down like you say is normally a bad battery error or false reading,,I've had free fall shut down aswell because my battery,on take off it was 100% only to go straight to critical at 400ft for no reason,got it to 72ft before battery turned itself off,this out come was not good either,very odd cause you say battery was still on,can you check voltage with multimeter, check it at 17.2 volt or close,,,can do simple 5 sec press on battery power button to check cell conditions, 4 ex,3 bit tired ,2,start looking for new battery,1,dont fly it even if shows 4 lights,,,this one bit of a brain teaser,either battery bad or something in the drone shut it down ,the warnings in app say basics but might give you a lead
 
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PhantomWetSuits

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Was there any chance that battery might have swelled some and that caused the disconnect as it only takes a fraction of movement for that to happen.
What shape was the actual battery in ?

This could also explain why the battery stayed in on the crash.
 
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As you said you have the drone since 2017 it is out of warranty for sure but this case is something that DJI should recognized as the system failure.
This case is exactly the case we all phantom pilots are afraid of. Nothing to do about it, nothing to predict it.
 
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My P4 had the same crack in the corner of the battery bay, except mine was on the upper right corner, and yours is in the lower right corner. My crack was discovered when it was 363 days old. DJI covered it under warranty and sent me a new drone, not a refurb. It's for sale now, very little flight time because I bought a P4P a month later.
 

RodPad

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Your flight data shows that you were in a stable hover when the data just stops.
You had a full battery at launch and didn't perform any sudden or severe moves.
There is a warning message of a Battery Error 1.3 seconds before the data ends.
That's not something I've seen before and could be significant but I'm not certain what error it's detected.

Perhaps it is crash damage, but perhaps it isn't.
The plastic in Phantom shells is of variable quality and it's not uncommon for cracks to develop without any crash.
Here's something I noticed when I reversed my P4 pro towards me to catch after a long flight at sea:

The battery would have easily been dislodged and I was lucky it had stayed together for the flight.
The drone had never been crashed, it had never even been landed as I always hand-catch.
I guess he didn't post any data from the Phantom itself?
Probably would be hard to retrieve it anyway.

Rod
 

Capt KO

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Had a p 4 battery with only nine charges fail yesterday. Immediately after takeoff just a few feet up I got the warning have a battery error land immediately. It landed with motors stopped. No damage but the battery has one cell that it says is disconnected or compromised. And it's a full quarter volt under the others. All four lights are on and it's no good. That's my second failure on batteries with less than 10 charges. No failures on my batteries with more.
 

PhantomWetSuits

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Had a p 4 battery with only nine charges fail yesterday. Immediately after takeoff just a few feet up I got the warning have a battery error land immediately. It landed with motors stopped. No damage but the battery has one cell that it says is disconnected or compromised. And it's a full quarter volt under the others. All four lights are on and it's no good. That's my second failure on batteries with less than 10 charges. No failures on my batteries with more.

Was that updated battery do you know ?
 
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Many thanks for the replies. I'm going to try powering the P4 up either today or tomorrow and I'll see if DJI Assistant can connect to it. If I can retrieve any data, I'll post it here.

Battery looks pristine. No signs of swelling and still showing full bars when I pressed the button today. I'll probably put it on my analyzer to see how much capacity remains in the battery but I'm fairly certain the battery is just fine.

Question, though. What discharge rate should I use when running the analyzer on the P4 battery? i normally work with smaller cells and packs and usually discharge at about a half Amp. I'm thinking that I want to more closely simulate how much the P4 requires in hover but I don't know what that is.

One more question (for now). Should I look to getting this thing fixed or just replace it? I see lots of Phantom 4 on eBay - both bare aircraft as well as full kits. Problem with purchasing a used aircraft is that you don't know the history. Opinions greatly appreciated.
 

Capt KO

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Was that updated battery do you know ?
The first one to go was a high-power with two charges and the one yesterday was the standard P4 battery. Both most likely 3 years old by now. Not used enough or maintained correctly before I purchased. Expensive lesson for me. Charging and discharging 10 batteries today. Heeding my own warning. Trying to keep a low number of charges on a battery ends in failure.
 

PhantomWetSuits

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The first one to go was a high-power with two charges and the one yesterday was the standard P4 battery. Both most likely 3 years old by now. Not used enough or maintained correctly before I purchased. Expensive lesson for me. Charging and discharging 10 batteries today. Heeding my own warning. Trying to keep a low number of charges on a battery ends in failure.

My batteries are 3 years old also and I had to retire one as it showed signs of being compromised also, going to keep a close eye now on the other 2 as 3 years might be a tipping point.
 
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Capt KO

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The ones I use often have never given me any trouble no matter how old. Just the ones with low charges. Use em or lose em, I guess. Seems the three month charge rule is the ticket to long life.
 
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Capt KO

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Your flight data shows that you were in a stable hover when the data just stops.
You had a full battery at launch and didn't perform any sudden or severe moves.
There is a warning message of a Battery Error 1.3 seconds before the data ends.
That's not something I've seen before and could be significant but I'm not certain what error it's detected.

Perhaps it is crash damage, but perhaps it isn't.
The plastic in Phantom shells is of variable quality and it's not uncommon for cracks to develop without any crash.
Here's something I noticed when I reversed my P4 pro towards me to catch after a long flight at sea:

The battery would have easily been dislodged and I was lucky it had stayed together for the flight.
The drone had never been crashed, it had never even been landed as I always hand-catch.
I assume you’re going to replace the mid-shell instead of repairing it? Or maybe make a battery strap to keep it in. Tough spot.
 

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Many thanks for the replies. I'm going to try powering the P4 up either today or tomorrow and I'll see if DJI Assistant can connect to it. If I can retrieve any data, I'll post it here.

Battery looks pristine. No signs of swelling and still showing full bars when I pressed the button today. I'll probably put it on my analyzer to see how much capacity remains in the battery but I'm fairly certain the battery is just fine.

Question, though. What discharge rate should I use when running the analyzer on the P4 battery? i normally work with smaller cells and packs and usually discharge at about a half Amp. I'm thinking that I want to more closely simulate how much the P4 requires in hover but I don't know what that is.

One more question (for now). Should I look to getting this thing fixed or just replace it? I see lots of Phantom 4 on eBay - both bare aircraft as well as full kits. Problem with purchasing a used aircraft is that you don't know the history. Opinions greatly appreciated.
Your Log was still on my screen, I was looking at it some more.

32.9 S Battery Error.
34.2 S Headed to China

1.3 sec?
You had plenty of time land it or hand catch-it. ;) :)
Probably not much info on the Phantoms Black-box.
But, maybe there is?

Rod
 
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I have two original batteries bought with the P4P (now more than two years old). Last month I bought the third original one.
With the last one I can easily do over 20 min flight to 30% left. With the first two the flight time is at least 2 min shorter but I think that is normal. Is it?
 
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The ones I use often have never given me any trouble no matter how old. Just the ones with low charges. Use em or lose em, I guess. Seems the three month charge rule is the ticket to long life.

Excuse me, can you share more info about "three month charge rule"? Thanks
 

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Excuse me, can you share more info about "three month charge rule"? Thanks
It is recommended that if you do not use your battery that it be charged and discharged every three months.It adds unused charges to the battery but will extend the life and prevent premature failure. That only shows up as two additional charges per year to save the battery.
 

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