Unexpected Auto Land at 1,100ft distance??

[powertowerpro]

I have been flying my P2V+ since June ’14 and have never had an issue. Over the months I have read several horror stories about fly-aways and other things that have gone wrong. I always considered myself lucky that nothing “unexpected” has ever happened to me…until today. I would like to solicit the help of the community to see why this might have happened:

Situation:
8 minutes into a routine flight
GPS Locked 10 satellite
NAZA-M but flying in GPS mode
Distance: 1,100ft
Altitude: 50ft
Phantom Battery: 60%
Controler WiFi battery: 98%
iPhone 6+ Battery 23%
Firmware 3.04 (I realize now that this is an outdated firmware and that the current version is 3.08)

All of the sudden at 59% the “Low Battery” Alert went off, the alarm sound started blaring and the red pulsing screen appeared. I wasn’t sure why this was happening and it took me a second to realize that the battery warning was going on even though there was plenty of battery left.

I started to pilot the Phantom back but it went into what appeared to be a failsafe landing mode and started landing at its current location. My understanding is that it should have flown back to the home point if it had a GPS lock (and it DID have GPS lock)

The phantom proceeded to land 1,100ft away from me. Once it landed I tried to cut the motors but instead it took off on it’s own and the RTH icon showed up on the screen. It then immediately landed again at its current location and I was able to cut the motors.

I just happen to be flying in a big field; I am usually flying over water or over cliffs. If this had happened yesterday I would be writing to you about how my Phantom auto landed into the ocean with 59% battery. This is very concerning.

After retrieving the Phantom I started it back up on the same battery and it worked fine. I then swapped batteries and flew for several minutes without incident. I would feel a lot more comfortable if I know WHY this happened.

I have several questions:
Why did the battery alarm go off at 59%?
Why did it not fly back to the homepoint?
Why did it land and then take off again?
Does the have anything to do with the battery firmware or reporting that DJI has been working on?
Does the iPhone battery ever trigger a RTH/Failsafe Landing?

Anyone have any ideas?

Many thanks in advance.
Jeff

 

[msinger]

When the DJI Vision app flashes red, that's the critical low battery level warning. The Phantom will auto land at its current position immediately.

Do you keep your battery contacts clean? If not, maybe try cleaning all of the contacts. DeoXit cleaner spray is commonly used for cleaning those contacts.

 

[Geoelectro]

Perhaps cleaning the battery connections would help. I had mine fall out of the sky from 80' with a fully charged battery. The screen said "Battery Communication Error".

These batteries communicate with the craft continuously and if there is a momentary break in that communication there is no way to know what may happen.

I started cleaning these connectors every few flights. I haven't had the problem since.
I use a typewriter eraser to lightly burnish the surfaces. Then, I apply a light amount of DeOxit contact cleaner with a Q-tip. Don't over burnish with lots of pressure as you could rub the gold plating off. Also, no need to overuse the cleaner. A very light amount will work fine. Too much attracts dust etc.

I hope this helps.

Geo

 

[powertowerpro]

I haven't even thought about checking the battery contacts. I will take a look and do the necessary cleaning. I really hope that is it. Thanks for the suggestions.

 

[msinger]

.

 

[4wd]

If it was reasonably high when this started you may have been able to maintain height and bring it back by giving almost full throttle. As suggested it can be a battery monitoring issue rather than a real failing battery, and there may be ample power left to return.

 

[Serpent]

Experienced similar - refer post: viewtopic.php?f=27&t=32452
If you physically check your battery is it bulging at all? I'm not yet convinced this is battery communication issues as in my case nothing showed up on the Vision App to suggest a battery communication error. The battery level dropped rapidly during a very short flight.

 

[Dirty Bird]

You could have regained control and continued home by flipping the S1 switch down and back up. You would have had to hold you throttle at or above 90% to maintain altitude. If you were high up it would be best to allow her to continue to bleed altitude along the way back. Difficult to say whether you could have made it back the entire 1100' but, at a certain point, the battery will become so low that it will simply shut down and the bird will fall. Obviously you want to be as close to the ground as possible before that happens.

Not sure what the air temp was at the time of your flight but, as temperature drops, the battery is less able to supply the high-current required by the aircraft. I haven't flown in over a month now because I don't trust the unpredictable nature of the batteries at low temps.

 

[saao]

I had the same issue a couple of days ago and the conclusion after cleaning etc was that my battery has something wrong with it only was charged 30 times. With me it happens at the 48% mark and when I yaw strange

 

[SteveMann]

The battery level dropped rapidly during a very short flight.

This is classic of a dead or dying cell within the battery pack. The voltage looks good until a load is put on it.

 

[knowonecares]

How Long Should A DJI Phantom Smart Battery Last? 30 cycles and it's toast? $5 per flight? I've only got a few cycles on my two batteries (Newbie) and one won't charge when I plug it into the DJI charger. It's at 70% maybe that's why? The other battery didn't seem to mind and it was at 85%. A post said that sometimes it may have to be discharged to almost empty before it will allow itself to be charged up. Large LiPos are new to me. I will store and charge mine inside those LiPo bags, and only charge them when they are below 30%, then we'll see if it's me or the battery.

 

[davisual]

Just cleaned my battery connections but realized I used contact cleaner and lube spray. Guess the lube won't hurt??? Opinions?

 

[Mopar Bob]

How Long Should A DJI Phantom Smart Battery Last? 30 cycles and it's toast? $5 per flight? I've only got a few cycles on my two batteries (Newbie) and one won't charge when I plug it into the DJI charger. It's at 70% maybe that's why? The other battery didn't seem to mind and it was at 85%. A post said that sometimes it may have to be discharged to almost empty before it will allow itself to be charged up. Large LiPos are new to me. I will store and charge mine inside those LiPo bags, and only charge them when they are below 30%, then we'll see if it's me or the battery.

Per the manual, if the battery is at 75% or higher, you have to turn the battery on before charging. I know you said it was at 70% but maybe that 75% rule isn't accurate. Maybe you have to do it even at 70%. Just a thought.

 

[BlackTracer]

Per the manual, if the battery is at 75% or higher, you have to turn the battery on before charging. I know you said it was at 70% but maybe that 75% rule isn't accurate. Maybe you have to do it even at 70%. Just a thought.

It is a fact that you have to turn on the battery for it to charge if it is above some level. Doesn't really matter if it is 70, 75, 85, or 10 %. If it doesn't start charging when you plug it up, turn it on.

 

[Jeremyconk]

The battery level dropped rapidly during a very short flight.

This is classic of a dead or dying cell within the battery pack. The voltage looks good until a load is put on it.

Totally agree with SteveMann... I have had the same problem with a battery pack.... No more than 40 flights with it, and now when it's under a load it wants to autoland at 60% or less... You can override the autoland by holding the stick in the full power position and get it home....

It really sucks that DJI won't stand behind their batteries.... I just mark that battery and know it can't be trusted for anything more than 5 minute test flights...

 

[eyecon82]

I has this happen to me once, it auto lands at 15 percent. Just gotta add some throttle

 

[DB_Cooper]

I'm having the same problem. The battery indicates 30% to 40% left and suddenly I get the low battery warning and the Phantom starts to land. I have to gain control by flipping the S1 switch and manually bring it back to a clear landing spot. Lucky only minor hard landing. When I recover the Phantom the last light on the battery is blinking so the battery is discharged. This occurs with all 4 of my batteries. I haven't flown for 3 months before this started occurring (this week). The batteries were not stored in a cool space during storage (I live in the tropics) so maybe they were overheated? Also left fully charged during storage. Upgraded to firmware 3.08 batteries 2.0 On dry discharge (no prop load) everything works fine. Batteries have only been charged 11 times. I'll buy 1 new battery and see if the problem goes away.

 

[DB_Cooper]

I'm having the same problem. The battery indicates 30% to 40% left and suddenly I get the low battery warning and the Phantom starts to land. I have to gain control by flipping the S1 switch and manually bring it back to a clear landing spot. Lucky only minor hard landing. When I recover the Phantom the last light on the battery is blinking so the battery is discharged. This occurs with all 4 of my batteries. I haven't flown for 3 months before this started occurring (this week). The batteries were not stored in a cool space during storage (I live in the tropics) so maybe they were overheated? Also left fully charged during storage. Upgraded to firmware 3.08 batteries 2.0 On dry discharge (no prop load) everything works fine. Batteries have only been charged 11 times. I'll buy 1 new battery and see if the problem goes away.

 

[erikgraham]

DB_Cooper... love the screen name.
(I can't help you guys on this issue but got a kick out of that. I'll go away now.)

 

[Pmcdn]

Perhaps cleaning the battery connections would help. I had mine fall out of the sky from 80' with a fully charged battery. The screen said "Battery Communication Error".

These batteries communicate with the craft continuously and if there is a momentary break in that communication there is no way to know what may happen.

I started cleaning these connectors every few flights. I haven't had the problem since.
I use a typewriter eraser to lightly burnish the surfaces. Then, I apply a light amount of DeOxit contact cleaner with a Q-tip. Don't over burnish with lots of pressure as you could rub the gold plating off. Also, no need to overuse the cleaner. A very light amount will work fine. Too much attracts dust etc.

I hope this helps.

Geo

How do you clean the inside of the battery part that connects (the female part)?