My P4 had been flying a little weird and would disconnect and RTH within 1/2 mile and maybe 300 ft up. Today, after reading some threads and re-linking my p4 to its controller, i still had the same issue. It flew out 2000+ feet with and disconnected, RTH and I regained connection within maybe 300-400 feet away from home point. As i was bringing it in, all of a sudden it was going haywire. It was still at about 300 feet up and just came crashing down and hit the asphalt. WTH, DJI?!

I have flight records and everything... this thing literally just went haywire and just plain lost control midair. I watched as it looked like the gimbal lost control at 364 ft up and just came tumbling down. It's a complete pile right now.... Please advise

I think DJI lost it
With all new products they got lost with basic thing - stable software / firmware

I've P4 , 2 days ago i try the new update but the P4 was not stable almost flip and crash to the ground.

I felt somthing worng and before it crash i shut it down

Wait DJI wake up and fix this issue!

Can you go ahead and post the flight log?

How do i post the flight log?

http://www.phantomhelp.com/logviewer/upload/

http://www.phantomhelp.com/logviewer/1R5NXLD9W3ZDWAY0H0MS/

Someone with more knowledge can give you better info, but it looks like the battery started doing some funky stuff.  When you gave it the juice in sports mode, it sped up whatever was happening. Just out of curiosity, did you calibrate compass just before you took off ?

I am stuck in a place where I can only see the flight record on an iPad, so it difficult to read, but the first thing that I noticed was you began the flight with a battery having only a 60% charge. Rule number one for flying Phantoms is never to start a flight on anything less than a fully charged battery.  Then I notice you are flying it in Sport mode, the quickest way to flatten your battery. Next the record reveals your battery's cell number 1 is dropping faster than the other cells. You would have received on-screen warnings for this, but you are still flying away from yourself at 32 mph. Look's like some pretty silly flying to me.

@alabama yeah when I reviewed the flight record I noticed that too, but I've flown it in normal mode and it was doing the same thing. My compass seemed fine. I didn't get any compass errors or anything prior

Geebax is an expert. He is right 99.9%.  Blunt, (as you can see lol) but very intelligent. He just tells it like it is.  I personally like that!

@geebax dually noted that it's always a good thing to fly with 100% battery charge. I knew it was going to be a short flight and I have my battery setting to pretty much RTH at 40%. I was testing it with the intention of doing a short flight and to see if the issue I was going to have the same connection issue if I flew 2000 feet away. If you look at where my battery was, it still had plenty of juice left in it. And I didn't get any warnings about battery issues either. So, can it with the criticism will ya?

Don't get mad at GEEBAX, he's more helpful than you know. He doesn't mean  to be critical, just shoots from the hip. He can solve a lot of problems, and teach you some great stuff.

@geebax. Don't get me wrong, you still brought some good insight, but you could've left out calling it silly flying.

wormz30 Posted at 2017-8-26 16:43
@geebax dually noted that it's always a good thing to fly with 100% battery charge. I knew it was going to be a short flight and I have my battery setting to pretty much RTH at 40%. I was testing it with the intention of doing a short flight and to see if the issue I was going to have the same connection issue if I flew 2000 feet away. If you look at where my battery was, it still had plenty of juice left in it. And I didn't get any warnings about battery issues either. So, can it with the criticism will ya?

OK, so you only want to hear nice things. The indicated battery percentage cannot be relied upon, as I said, it is not a safe practice to start a flight on a partially discharged battery. I don't know what you want to hear, but if you post a flight log then don't get out of shape when someone points out that it indicated poor decisions.

Not mad. @alabama. There was no indication that there was a battery issue. No warnings other than the disconnection at 2000 feet and the "high-wind velocity"

@geebax. Not that I don't appreciate the insight, because I do. But calling it silly flying right now, it doesn't help. Again, I've flown with a partial charge before with no problem. As I said before, my P4 started flying like that since the firmware update. I've never had issues with the battery before either.

Same battery yesterday, same scenario. Battery started out at 82%. http://www.phantomhelp.com/logviewer/C2QM8VY87DJC7KIYSA7Q/

         I know that high wind velocity goes along with the gps no match warnings you were getting.  And Geebax is dead on about the battery. When it's malfunctioning the percentage left will be false.  I mean
when you go out over 2000 feet and then comeback using only 20 percent. Something ain't right lol

@alabama looking back at the last flight flight record I posted, battery seemed fine and it ran into the same issue sans complete failure

wormz30 Posted at 2017-8-26 17:15
@geebax. Not that I don't appreciate the insight, because I do. But calling it silly flying right now, it doesn't help. Again, I've flown with a partial charge before with no problem. As I said before, my P4 started flying like that since the firmware update. I've never had issues with the battery before either.

Geebax gave you the answer back in his first post.
You may have flown with a partially discharged battery and got away with it in the past but it's asking for fall-from-the-sky trouble.
I'd have a lot more in my spare battery account if I had $1 for every case I've seen just like yours.
You started with a battery that could only give 15.5V with no load.
A fully charged battery reads a touch over 17V
Within 30 seconds on takeoff, your battery is down to 14.25V (a healthy battery would be 15.8V).
At 52 seconds when you go to battery draining sport mode, you have all 4 cells at 3.4V for a total of 13.8V and falling fast.
When you get to 3.3V per cell, the game is over and you're already perilously close.
At 52 seconds a healthy battery is still showing 4.0V per cell.
You continued to push it hard for a further 2:24 which would have effectively drained the battery.

With a partially discharged battery the % indicator gives you a false impression.
The 60% you think you started with was not 60% of a healthy battery.
Flying with a partially discharged battery is very silly flying and asking for trouble.
Perhaps that's the reason DJI advise you to never do it??

Labroides Posted at 2017-8-26 19:50
Geebax gave you the answer back in his first post.
You may have flown with a partially discharged battery and got away with it in the past but it's asking for fall-from-the-sky trouble.
I'd have a lot more in my spare battery account if I had $1 for every case I've seen just like yours.

You know what? I would've accepted the answer from geebax if it was stated this way. 100% and even taken the "silly flying" comment along with it. Never heard of this issue before, never seen an issue like this before. But even with my battery still at above 40%, can it really take such a massive drop in juice that it literally stops operating in mid-flight like that?!

wormz30 Posted at 2017-8-26 19:58
You know what? I would've accepted the answer from geebax if it was stated this way. 100% and even taken the "silly flying" comment along with it. Never heard of this issue before, never seen an issue like this before. But even with my battery still at above 40%, can it really take such a massive drop in juice that it literally stops operating in mid-flight like that?!

There have been plenty of cases where it has.
For fall from the sky incidents, the first thing I look at is starting battery levels.
It takes a lot of typing to spell it out in full.
GB was being brief but accurate.
The % indicator is only good if you start with a full battery.
Voltage is what the Phantom cares about and when you get down to 3.3V per cell the game is over.

Labroides Posted at 2017-8-26 20:20
There have been plenty of cases where it has.
For fall from the sky incidents, the first thing I look at is starting battery levels.
It takes a lot of typing to spell it out in full.

Damn. Then in that case, @geebax I owe you an apology and ask for your forgiveness. That still sucks donkey balls. I wish i had even known about this in the beginning. Let's see what DJI ends up saying/doing.

every flight is a learning flight....no worries bros. hope DJI can speedup and give advices on the bird.............

I need simple help, my P4 pro intelligent battery is charging funnily. It goes like 1 2 3, 1 2 3, 1 2 3, 1 2 3 4, 4 3 2 1, Off for like 2s than repeats the loop. Is this normal?

So in theory this could happen and you get called silly:

Fly at 100% film nice footage, return and land at 60%.
Drink some tea and a biscuit.  Dunk your biscuit if you like it that way.
Fly out at 60% film some nice footage, return home in Sports mode at 40%, crash, get called silly on forums.

I imagine quite a few people do multiple flights out on one battery for short filming clips and maybe even dunk their biscuits.

Yes, if they have healthy batteries. Wormz didn't.  Dunking biscuits can be hazardous to your drone lol.

ALABAMA Posted at 2017-8-27 03:28
Yes, if they have healthy batteries. Wormz didn't.  Dunking biscuits can be hazardous to your drone lol.

My new P4p crashed today after a brief 4min flight,  immediately after the latest upgrade.
It fell onto concrete from 39 ft and is severely damaged ....... except for the props.
Not a scratch or a scuff on any of the blades
I am pretty sure that the motors shut down in flight.
What can I do?

ALABAMA Posted at 2017-8-27 03:28
Yes, if they have healthy batteries. Wormz didn't.  Dunking biscuits can be hazardous to your drone lol.

My new P4p crashed today after a brief 4min flight,  immediately after the latest upgrade.
It fell onto concrete from 39 ft and is severely damaged ....... except for the props.
Not a scratch or a scuff on any of the blades
I am pretty sure that the motors shut down in flight.
What can I do?

fans11f25cc2 Posted at 2017-8-27 04:32
My new P4p crashed today after a brief 4min flight,  immediately after the latest upgrade.
It fell onto concrete from 39 ft and is severely damaged ....... except for the props.
Not a scratch or a scuff on any of the blades

Start a new thread and upload your flight log to http://www.phantomhelp.com/logviewer/upload/

You will also want to sync your log and contact DJI if you think there is warranty repair due.

@alabama how would I have known if I didn't have healthy batteries? I never got any warnings about my batteries

wormz30 Posted at 2017-8-27 05:30
@alabama how would I have known if I didn't have healthy batteries? I never got any warnings about my batteries

There should be a bettey tester available somewhere.   We are flying this thing into the air... we can't afford to have batteries go bad.  There should be some sort of tester, maybe even a tester built into the charger, just like my AA charger.

Labroides Posted at 2017-8-26 19:50
Geebax gave you the answer back in his first post.
You may have flown with a partially discharged battery and got away with it in the past but it's asking for fall-from-the-sky trouble.
I'd have a lot more in my spare battery account if I had $1 for every case I've seen just like yours.

Labroides  

I've read about this issue before, or something similar, that said, I have a few questions about this and what you wrote, if you would not mind.

1)  How can you tell you have a bad battery?  Are there any indicators or warnings to look for that will tell you something is wrong and going bad, before an event like this?

2)  Why is this system designed in a manner that if you use a partially discharged battery you can’t get accurate indications of its charge state?  Conversely, why does a fully charged battery provide more accurate information (I’ve read that even that is not necessarily so either)?  Why is there a difference between partially charged and full?

3)  3.3V appears to be a magic number, what is that based on?  Could there have been a problem with the drain rate, due to being in Sport mode, which caused the system to not keep up with the battery level/state?

4)  It’s my understanding, based on the manual, that when the battery reaches the Critical Low state it will initiate an RTH and/or land immediately.  Can you explain why that did not happen here?
Thanks, I’m sure your answers will be beneficial and help immensely, and possibly aid others in preventing them from getting in to similar situations.

Genghis9 Posted at 2017-8-27 05:40
Labroides  I've read about this issue before, or something similar, that said, I have a few questions about this and what you wrote, if you would not mind.1)  How can you tell you have a bad battery?  Are there any indicators or warnings to look for that will tell you something is wrong and going bad, before an event like this?

2)  Why is this system designed in a manner that if you use a partially discharged battery you can’t get accurate indications of its charge state?  Conversely, why does a fully charged battery provide more accurate information (I’ve read that even that is not necessarily so either)?  Why is there a difference between partially charged and full?

I'm also interested in the answers to Genghis9's questions.  I've flown my fair share of flights with non-fully charged batteries with no issue, nor have we had any issue with my university's Inspire or Mavic.

Ok now I'm also interested about that too.

Welp... @Geebax, @Alabama, @labroides, here it is... I found a perfect thread to support what you guys were talking about.
https://forum.dji.com/thread-51147-1-1.html

Thanks for making it clear. This was the exact scenario and it played out like that

My P4 batteries had been partially charged for a few days. I had used them a few days before, shortly and put them back in my bag. Pulled them out a few days later to do a short test flight of the drone, not fully charged. Put the drone into sport mode, and of course you know how it ended. It was the perfect storm of stupidity or a really bad rookie mistake. Drone was already acting funny since the new firmware update. Throw in a partially discharged battery. Throw in Sport mode. Drone falls out of the sky and crashes.

Tested both of my batteries, 90-100% life left in these batteries (I did the 5-second button-hold test and they're fully green).

So now, question is... should i just get a refurbished p4 or should i save up and get the P4P? Promise i'll do the following from now on:

1) Charge my batteries to 100% everytime
2) Not going to fly batteries that have been sitting in my bag, uncharged for days.
3) Not go off on Geebax
4) Bow to Geebax

A similar situation occurred for me, after the firmware was updated it started flying (92% of the battery charge), everything went as usual: when the connection was lost, it returned to the take-off point. 41% lost contact and did not return. Everything ended well, I found my P4P +, but now I'm afraid to fly far. Maybe someone started with this problem, what could be the reason.
Log:
http://www.phantomhelp.com/logviewer/KFDKH8L6GQ6AGX5X1NUO/

LOL it ended up half a mile away. Did it crash land into something soft? How did it "End well"?

wormz30 Posted at 2017-8-26 15:28
http://www.phantomhelp.com/logviewer/1R5NXLD9W3ZDWAY0H0MS/

Although you were running very low on battery, and the battery % figure was very inaccurate, the actual reason it fell out of the sky was that your ultrasonic sensors thought that it had landed on something, you then pulled the throttle full down as you do when you land to cut the motors and a few seconds later it cut the power to the motors since it thought they were no longer needed.

Do you have a gimbal guard or something mounted under the aircraft that it could mistake for the ground?

If it hadn't fallen out of the sky then you would have had a forced landing due to low battery voltage, probably within 1 minute, but it would have landed rather than fallen.

The % battery figure is an estimation since there is no way to actually measure how much power is in a lithium battery.  Always fully charge your battery no more than 24 hours before the flight so that it knows that the battery is full and thus at 100%, for new batteries or ones not used for ages, don't use them below 30% for the first few charges while they learn their true battery capacity so that 100% - amount used can give an accurate % figure at all times.