Hi all, I just went out and flew my P4 running newest firmware ( i kno peeps want it listed to be sure), I have been flying a while on this fw with my mini ipad 2 and had no issues. After a coupleof fly bys I decided to shoot out to a distance I have flown many times before. When I got too 5500 feet out and 200 feet up, I heard the low battery warning, when I looked down battery said 72%. Needless to say I turned around and with my heart pumping I flew straight back home. There was a side wind, my P4 was tilting to compensate for it when it was coming in, and I was flying in sport mode, not sure if that had anything to do with it. I landed, restarted my bird still 58% battery life, and flew around a bit more, not too far out this time, but dudnt get the low battery warning untill it hit what its set @, I have low battery warning set @ 20% and critical warning @ 10%. Looking @ battery setting when this happened, and checking advanced setting, showed me everything was fine, even tho the low battery warning came up @ 72%, it was quite scary to be that far out and get that warning, any idea as to why this may have happened?

I would hover it down and drain it to 7% then re charge it again and let us know. This happens if you let your batteries sit for too long and they start to discharge.

My batteries are set too discharge in 3 days, they had sat 24 hours, and were 100% when put in... as for the 8%, mine were done 3 charges ago... altho I have read that newest manuals dont have this in them anymore, and that doing this can damage the life of the battery... another site tho

I once put a discharged battery in by accident and flew out a few thousand feet.   When the battery warning went off, I only had a real 30%..   I know that heart pounding feeling

Having the low battery warning pop up at 72% when the setting is 20 percent is strange.  This is just a guess, but what is the voltage of each individual cell?  If one is really low it could be what is causing the problem.   They should all be within a couple of percent of each other.

jwt873@gmail.co Posted at 2016-8-6 15:37
I once put a discharged battery in by accident and flew out a few thousand feet.   When the battery  ...

thanx for the reply, I looked and tho cant remember where they were, they were all the same, and in the green.... I was flying in sport mode with a good cross wind, I wondered if maybe it was just a little too hard on the batteries and didnt like it... I had noticed that the track up above that tells you time left available to fly and whats needed to get to Home( my terminology not best I kno, please bear with me) was yellow instead of green. When I check my flight record it actually stopped @ 73% battery life, and then started another, flight log, so I dont kno what happened, just that when I restarted my drone after landing, my battery warning went away, as it was about 58% when I landed, and I flew out the battery to 13% with no issue

Heebus Posted at 2016-8-7 05:43
thanx for the reply, I looked and tho cant remember where they were, they were all the same, and i ...

I suspect what happened was the aircraft making a calculation as to whether it could get home with the amount of power in reserve. I note from your description, you were 5500 feet out and there appeared to be strong winds. The aircraft is continously trying to figure out if it can get back to home from wherever you fly it, and in this case I think it figured out that it was going to be a stretch.

Geebax Posted at 2016-8-7 00:53
I suspect what happened was the aircraft making a calculation as to whether it could get home with ...

It landed with 58% battery, if what you say is correct then there is something seriously wrong if it came back from 5500ft using only 14% battery, it doesn't tally , I also think when P4 is flying downwind it doesn't have the brain to figure out that to go back it will be flying into the wind, that's for the controller to figure out.

hallmark007 Posted at 2016-8-7 10:18
It landed with 58% battery, if what you say is correct then there is something seriously wrong if  ...

There is no navigational intelligence in the controller. Why would there be, it is not going anywhere? All the navigational computations are contained within the aircraft, just as they are in full size aircraft.

I agree it is not logical in this case, but the aircraft does know when it is flying downwind, and it also knows about crosswinds, it is all related to motor current. If it is having trouble maintaining position or track due to winds, it takes all that into account in trying to figure out if it can get back to where it started. If it fails on the conservative side, then that is better than the reverse.

hallmark007 Posted at 2016-8-6 20:18
It landed with 58% battery, if what you say is correct then there is something seriously wrong if  ...

I had a cross wind, its why I flew this direction, I checked to see what the was doing @ that height before I flew out,I didn t want to fly into the wind, or have a tail wind. As near as I can figure, with the cross wind hitting me, and flying sport mode, maybe my P4 was working over time to stay stable/steady forward, and I pushed it too far. I flew out with about 20% battery spent, and when I came back used another 14%, landing with 58( or abouts) left. I think it was a matter of over working, and the batteries ( or more likely) the bird calculated it wasnt gonna make it back...

footnote... I just made the same pass with the same battery, in P mode flew out just shy of 13 000 feet ( a record for me) and back, no issues or warnings, there was no wind up there tho, and took it easy on my bird... might post the video later, but it'll be a long one, unless I clip the video one way

Geebax Posted at 2016-8-6 21:43
There is no navigational intelligence in the controller. Why would there be, it is not going anywh ...

I agree, atleast I think so, if your saying I might have pushed it a little too hard, my bird had a pitch to her fighting the cross wind, and being in sport mode it may have been too much

Heebus Posted at 2016-8-7 12:28
I agree, atleast I think so, if your saying I might have pushed it a little too hard, my bird had  ...

Yes, I think you are right in what happened.

Distance and Altitude are all over the place with the recent firmware.  It's also possible that the distance was not correct when the processor calculated that it's time to come back.

As far as wind,
How does the P4 add the wind velocity into it's smart Return to Home calculation?

MD_Icarus Posted at 2016-8-7 13:44
Distance and Altitude are all over the place with the recent firmware.  It's also possible that the  ...

'How does the P4 add the wind velocity into it's smart Return to Home calculation?'

The aircraft knows when it applies known speed differentials to the motors, that the speed over the ground should be a given value. If the GPS calculations then reveal that the speed over the ground is not what is expected, the aircraft makes an assumption that something is changing the speed over the ground, and that most likely, it is wind. If the aircraft finds that is is fighting a wind, it knows that will have a proportionate additional drain on the battery reserves. It therefore calculates a time-to-return-to-home based on that knowledge.

Just checked out my flight data on healthy drones, took 18.9 mile an hour gusts when I hit the water, must have been it... by the by, I checked flight data on second test, 25k round trip, best so far... video coming soon, being up;oalded as we speak... crossing that lake I get some serious side winds, did it just before sunset, nice and calm, first time getting good enough signal to cross the lake, but getting further and further every flight

Hello, Heebus, according to your description, that may be a misinformation.If you can provide a screenshot when the APP show low battery warning, that will be helpful.

Geebax Posted at 2016-8-7 02:43
There is no navigational intelligence in the controller. Why would there be, it is not going anywh ...

Sorry I meant operator not controller, the aircraft can or try to figure out how much battery is needed to get home and is equipped to override the operator instructions, it's a fantasy to think the aircraft is trying to work the strength of the wind and the power of the battery to do what you say it done, and if that is the case why would it get it so badly wrong, why also can it not give the same feedback to the operator as it does with airplanes.
I would like to think, that what you say is possible and it's a really good idea for a UAV, but living in the west of Ireland on the Atlantic coast I have on occasions struggled to get my aircraft home, believe me it was me trying to get the aircraft home, not the aircraft panicking to get there.
I like the way your thinking about what you say, it would be a great addition to P4 if it would send same information back to the operator.

hallmark007 Posted at 2016-8-7 20:41
Sorry I meant operator not controller, the aircraft can or try to figure out how much battery is n ...

OK. Well, it does make those calculations, it has been said by DJI some time ago. Sometimes, under conditions where it might encounter very strong gusts, it might make the calculations somewhat iffy, but frankly I would rather it errs on the conservative side.

As for reporting to the operator, you will learn, if you hang around here long enough, that DJI is not particularly good at communicating anything to owners or operators. Remember, even when writing program for these aircraft, it is not their native language.

Geebax Posted at 2016-8-7 18:15
OK. Well, it does make those calculations, it has been said by DJI some time ago. Sometimes, under ...

Tho I agree with everything you said, even when I was seconds from landing, the low battery warning was flashing, still with better then 50% remaining... powered down the bird, powered back up and flew out the rest of the battery... If a moment of over use of the battery due to wind, and flying in sport mode made the bird figure it was in dager of not making it home, you would think after a few minutes it would recalculate and realize it would make it, but maybe I am over thinking it, or expecting too much

Sounds  like it miscalculated the battery needed to get back. You can see the results of it's calculation by where the "H" is on the battery line. If you fly past that H you will get the battery warning. It normally recalculates  as you keep flying. So the question is why didn't it? Maybe something about the sport mode.

KM5RG-Robert Posted at 2016-8-7 19:27
Sounds  like it miscalculated the battery needed to get back. You can see the results of it's calcul ...

exactly, I was never even close to the H on the battery line, I still had 58% battery life when I landed, and still had the low battery warning flashing, powered down the back up all was fine... I have read on a few website this has happened to a few pilots, and is being chalked up a a glitch in the app... still worth looking in too

Geebax Posted at 2016-8-7 23:15
OK. Well, it does make those calculations, it has been said by DJI some time ago. Sometimes, under ...

Well maybe it does make those calculations, I have not seen it written anywhere, it's not in the manual, it's also not something I will be depending on , I bow to your superior knowledge.

hallmark007 Posted at 2016-8-8 09:56
Well maybe it does make those calculations, I have not seen it written anywhere, it's not in the m ...

'I bow to your superior knowledge.'

Hah, I use that line too, and it does not mean what it appears to mean......

Geebax Posted at 2016-8-8 01:13
'I bow to your superior knowledge.'

Hah, I use that line too, and it does not mean what it appear ...

It does in my book , if I've learnt something in my life it is , it doesn't matter who's wrong or who's right  it only matters what I have learnt from my experiences, have a good one mate.

I have had this happen to me a few times, I look at the battery level and see it is over 70% so just cancel the warning and keep flying.  So far so good.  In fact it happened on this flight and I was still able to complete my mission and return ok.

MAD35 Posted at 2016-8-8 05:25
I have had this happen to me a few times, I look at the battery level and see it is over 70% so just ...

how did you cancel the warning?

Heebus Posted at 2016-8-8 18:11
how did you cancel the warning?

Hit the big X that popped up on my screen and kept flying

Glad to see that I am not alone with this issue (is that a thing to be glad about..)

I purchased the Phantom 4 less than a week ago. I have done a few test flights with it, and it is just wonderfull. But there is a but. Yesterday when I was playing with the DJI GO camera and video settings (the copter on the floor powered on but not armed). As I was doing the settings, I noticed the "Critically Low Voltage Aircraft Landing" message; I came periodically  quite a few times actually. The message came back almost instantly when I just closed the warning (pressing the X in the warning box). I got rid of the warning for a longer time by restarting the copter and changing the battery (though, the warning re-appeared in about 10 minutes). The two batteries I used are new and were more than 90% charged. The firmware on the radio and on the copter is latest.

The odd thing is that the cells all had more than 3,9V on them when the critically low voltage appeared. I.e. there was plenty of juice left, and there should not have been any reason for the critically low voltage.

Today I took the phantom to the Finnish service, but they could not repliacate the error. They made a test flight, and it worked allright. Still, I feel hesitant to take the copter high or above any buildings or water if this error takes place and really brings it down violently.

Just out of curiosity what is your RTH altitude set too?, I accidentally put 500 meters in this box once and was getting battery warnings at 80%!

Bennyboy1983 Posted at 2016-8-11 20:16
Just out of curiosity what is your RTH altitude set too?, I accidentally put 500 meters in this box  ...

60m. I find that odd that it would play any role. Then again, it is SW..

LasseK Posted at 2016-8-12 01:09
Glad to see that I am not alone with this issue (is that a thing to be glad about..)

I purchased th ...

I'm sorry you had that issue, it's a notification error. The battery clearly has plenty of juice and if that popped up in the air it wouldn't make it land since the battery is fine. But you shouldn't see that notification again, and if you do then delete/reinstall the app.

Also, if you ever do get the battery low and get that message all you have to do is give it throttle so it doesn't land and you can fly home if your close by. Hopefully you pay attention and never fly the battery down to the critical low voltage.

MAD35 Posted at 2016-8-11 11:02
Hit the big X that popped up on my screen and kept flying

so you didnt cancel the warning, you canceled thr RTH, low battery warning flashes up where you get the safe to fly notice

I hope that it still waits for the 10% level to initiate a Landing?  Let's hope this bug does not force a landing when th ebattery is above the 10% critical level.

Has anyone seen such a critical warning when the battery was above 10% or whatever level you have set the critical level?

MD_Icarus Posted at 2016-8-12 05:10
I hope that it still waits for the 10% level to initiate a Landing?  Let's hope this bug does not fo ...

The DJI importer / service wanted to take my Phantom 4 under investigation. As it was newish (6 days), I got a new P4. The new P4 has worked flawlesly and has not shown the same errorneous message of critically low voltage.

In the conditions you are flying with a strong wind, maybe it was the SMART RTH kicking in!

This happened to me also.  Full battery and the warning came up prior to take off.  Any suggestions on how to fix would be greatly appreciated as it is somewhat disconcerting

cheers

Nigel

nwoodman Posted at 2016-8-28 11:28
This happened to me also.  Full battery and the warning came up prior to take off.  Any suggestions  ...

did u just switch out your battery with a used 1?, cuz I get a glitch of this when I do that, your screen shows now homepoint yet, if u get 1 u should be good I think thats why u got the low battery, but should disapear, my problem I think was from too much speed and wind causeing it to glitch and think it didnt have enough power to make it home