why does flying on an less than 100% charged battery cause problems

VRS or Vortex Ring State was an issue for the original Phantoms and the P2 series.
DJI slowed the descent rate twice to reduce it.
With the P3 and P4 series VRS was eliminated by angling the motors which were vertical on earlier models.
It is completely safe to descend vertically in still air with a P3 or P4 Phantom.
I understand where you are comming from. But I disagree. I have descended my phantom 4 straight down in calm weather and it got into the Vortex Ring State and crashed, hard, from 120m. Yes that time I was in sport mode, but it is still a very real problem with the P4.
A couple of days ago I was flying in calm weather, there was some fog around and I was trying to take photos of it but I had to keep watching the drone because it kept getting into the early stages of the Vortex Ring State. Even when it was staying still. And if I had left it, I don't think I would still have my drone
 
P4 is reputed Vortex free as mention by meta4. Many pilots reported here full stick down to land without any issue (some translation is best of course and can help boost descend speed). Were you flying at high altitude or i.e hot air over relief? I'm thinking at poor air density conditions.

If course if you're flying with last firmware there might be something else.
 
I understand where you are comming from. But I disagree. I have descended my phantom 4 straight down in calm weather and it got into the Vortex Ring State and crashed, hard, from 120m. Yes that time I was in sport mode, but it is still a very real problem with the P4.
Sport mode allows a faster descent.
I've never heard of a P3 or P4 entering VRS when descending at full normal P-GPS speed.
I'd done it myself many, many times as have many users.
The manual for the P4 pro advises you to be careful in full Sport mode descent speed because it has a longer time to brake.
The aircraft’s descent speed is significantly increased in S-mode (Sport). A minimum braking
distance of 164 feet (50 meters) is required in windless conditions
That may be what you encountered.
 
P4 is reputed Vortex free as mention by meta4. Many pilots reported here full stick down to land without any issue (some translation is best of course and can help boost descend speed). Were you flying at high altitude or i.e hot air over relief? I'm thinking at poor air density conditions.

If course if you're flying with last firmware there might be something else.
The first time (the time I crashed) my drone got into the vortex ring state, I was flying on a sports oval on a calm sunny day.I started at 120m in sport mode and was timing the decent to see how fast the drone comes down. I have old fermware so that should not be a problem. The second time recently I was flying on a still morning and there was a lot of fog about so the air was not thin. It was fairly cool as well, I think I was about 50m and trying to get all round shots (staying at the same level) of the cloud but the drone kept getting into the early stages of the Vortex Ring.
Maybe I am just over cautious since the crash. And maybe the second time was just the drone adjusting itself. But from the experience of the first crash the drone props on the air was making the same sound as before and the drone was definitely desending when it shouldn't have been.
 
The first time (the time I crashed) my drone got into the vortex ring state, I was flying on a sports oval on a calm sunny day.I started at 120m in sport mode and was timing the decent to see how fast the drone comes down. I have old fermware so that should not be a problem. The second time recently I was flying on a still morning and there was a lot of fog about so the air was not thin. It was fairly cool as well, I think I was about 50m and trying to get all round shots (staying at the same level) of the cloud but the drone kept getting into the early stages of the Vortex Ring.
Maybe I am just over cautious since the crash. And maybe the second time was just the drone adjusting itself. But from the experience of the first crash the drone props on the air was making the same sound as before and the drone was definitely desending when it shouldn't have been.

If you can retrieve any DAT files for flights where you think you saw VRS then I'd be very interested to see them. The flight data signature of VRS is relatively unknown (I think) since it has not been seen much in the later Phantoms that log such data.
 
If you can retrieve any DAT files for flights where you think you saw VRS then I'd be very interested to see them. The flight data signature of VRS is relatively unknown (I think) since it has not been seen much in the later Phantoms that log such data.
Okay... how do you retreve DAT files? are they in with the photos/videos or in a separate folder? Also do they get wiped/replace over time?
 
I am just wondering, since the crash I have moved my photo&videos to a hard drive so can I get the files off the hard drive. Will check and get back to you.
 
I am just wondering, since the crash I have moved my photo&videos to a hard drive so can I get the files off the hard drive. Will check and get back to you.
The .DAT files are not on the same SD as the photos and videos. They are on an internal SD that can only be accessed by using DJI Assistant 2. To see how to retrieve the .DAT files take a look at
How to retrieve a V3 .DAT File.
 
If you can retrieve any DAT files for flights where you think you saw VRS then I'd be very interested to see them. The flight data signature of VRS is relatively unknown (I think) since it has not been seen much in the later Phantoms that log such data.
Sorry to disappoint you, (and myself) but it seems that the files have been replaced. I am not sure why but fairly soon after the crash I was seeing what information from the files I could get and they were none with the right date/earlier enough.
 
I am now wondering if it is alright to completely delete all the files from my tablet regarding dji and restore the factory defaults on the drone. In the hope that if anything goes wrong in the future I will have a "fresh start" and clear memory for important files.
 
I am now wondering if it is alright to completely delete all the files from my tablet regarding dji and restore the factory defaults on the drone. In the hope that if anything goes wrong in the future I will have a "fresh start" and clear memory for important files.
The tablet files don't get erased to make room for newer files. So, no need to erase those. The .DAT files on the AC itself are the ones that get erased to make room for the newer files. But, you can't erase those .DAT files; you can only access them via the DJI Assistant 2. Just make sure the next time you have a VRS incident that you retrieve the .DAT for that flight so that we can take a look.
 
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**** near willing to bet you 10 bucks that the problem with the drifting is because you need to Calibrate the IMU on the Phantom, regardless of what anyone says. Have run into the identical problem before. Once I calibrated the IMU on my Phantom and it was in GPS mode, it quit drifting completely and just hovered in place like it was suppose to. I know this will help.
 
Well, thanks for the reply but it does not help my question. I have read repeatedly not to fly on a non fully charged battery. There was zero wind and i had 17 sattelites. and it never changed to atti or anything other than the normal flight mode. When I landed I flew up overhead and it did the same type of drift. What does the starting point of the battery being an estimate have to do with erratic flight characteristics, that is the question. The drone was landed and then launched again without powering down. That should eliminate the BS about the starting point being an estimate.Oh and my fingers certainly were not wobbly. Looks like flight on a non 100% charged battery causes some malfunction that DJI cant figure out.
captain kush

I completely concur with you. I started a flight last week, waypoint recorded. I flew out 1700 feet, lost signal, aircraft disconnected and even though I had the bird set to return to home if disconnected, 10 seconds after it disconnected and promptly landed right where it was.
The battery still had one solid bar on it, which as I understand means there was 25% battery left. This is the only time I have ever flown with a less than fully charged battery, and this is the only time this is ever happened. 2+2 = 4.
 
I completely concur with you. I started a flight last week, waypoint recorded. I flew out 1700 feet, lost signal, aircraft disconnected and even though I had the bird set to return to home if disconnected, 10 seconds after it disconnected and promptly landed right where it was.
The battery still had one solid bar on it, which as I understand means there was 25% battery left. This is the only time I have ever flown with a less than fully charged battery, and this is the only time this is ever happened. 2+2 = 4.
This might me 1+0=1.

One solid light means the pack could have been anywhere from 12.5 to 25% charged.

The likely scenario in this case is the AC autolanded on signal loss as it was determined the charge level was insufficient to RTH (before hitting critical @10%).
 
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I completely concur with you. I started a flight last week, waypoint recorded. I flew out 1700 feet, lost signal, aircraft disconnected and even though I had the bird set to return to home if disconnected, 10 seconds after it disconnected and promptly landed right where it was.
The battery still had one solid bar on it, which as I understand means there was 25% battery left. This is the only time I have ever flown with a less than fully charged battery, and this is the only time this is ever happened. 2+2 = 4.
The user you are agreeing with was very confused.
Read post #6 for an explanation
If you have an unexplained flight incident, the way to find out what caused it and learn from the experience is to look at your recorded flight data.
Go to DJI Flight Log Viewer
Follow the instructions there to upload your flight record.
Come back and post a link to the report it provides
 

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