So I've had my batteries and drone sitting in the case for a couple of weeks as I never got around to using it after charging everything. I had 2 solid bars on both batter and controller.
I launched it straight up to 40 or 50mtrs and turned it around 360 degrees. I got a warning that batter was low and as soon as I pressed on the right joystick, the drone just went full ball in one direction. It was like the accelerator was stuck on. After not being able to bring it back (and it was fast heading over suburb houses), I hit the return home button and it came home. It was certainly a panic moment.

https://www.youtube.com/channel/UCp3ksKyobrSY1fpGsmRLnpA

You should always top up those intelligent flight battery packs, especially after letting them "auto discharge".

It's important to fly with a full battery, particularly if trouble happens, like it almost did there, with yours.

I always check all my four of my intelligent flight batteries the night before, or in the morning, of a planned outing, with my DJI Phantom 3 Pro' drone.

Fly smart, fly safe, and bring it back, without turmoil or troubled flights. ;-)

You were very lucky, fortunate that it didn't fly off, into unknown territory. Close only counts with shotguns. Ha


RedHotPoker

You must have missed the note in the manual that advises to only fly with a fully charged battery.
A lot of stories that end with the Phantom falling from the sky begin with a partially discharged battery.

But the battery is unlikely to cause the situation you described.
To get a better idea of what went wrong go to http://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.

Come back and post a link to the report it provides and someone might be able to work out the cause of the incident.

Labroides Posted at 2016-11-20 17:16
You must have missed the note in the manual that advises to only fly with a fully charged battery.
A lot of stories that end with the Phantom falling from the sky begin with a partially discharged battery.

Thanks for the response. Yeah, I thought I was taking a reasonably calculated risk flying it straight up and down with batteries on 2 bars, but lesson learnt.

I checked the Flight Report, things were running ok until the first message:

"Critically Low Power. Aircraft Landing. Throttle up to reduce the speed of descent and use sticks to avoid obstacles"

The Flight Mode changed to "Auto Landing". This explains why I thought it was coming down by itself when I wasn't pulling down.

Then 10 secs later, I start getting "Yaw Error" messages for 18 secs, at which point the Flight Mode switches to ATTII with the message "Compass Error. Exit P-GPS Mode; Yaw Error"

"Yaw Error" messages continue for another 3 secs and then the Flight Mode switches to "P-GPS" for a few seconds.

Flight Mode then changes to "Go Home" with the message "Return-to-Home-Initiated"

On another note, Cell 1 to Cell 4 were getting up to 0.037V Cell Deviation if that makes any sense...

DRONE EYE Posted at 2016-12-6 23:38
Thanks for the response. Yeah, I thought I was taking a reasonably calculated risk flying it straight up and down with batteries on 2 bars, but lesson learnt.

I checked the Flight Report, things were running ok until the first message:

If you post a link to the Phantomhelp report, you could get some extra feedback.
I suspect the battery voltage was very low, which is what happens with a partially discharged battery.

As regards the flight pattern - others are better at answering that than I am ....

But regards the battery cell voltages .... 0.037v deviation is nothing. If it was 0.37v - that's a different matter.

Lipo's are not advised to be stored full charged. Luckily DJI battery's have a self discharge to storage function built in. Personally I don't like even a couple of days full charged - so I will discharge mine manually if not in use to the nominal level of about 3.75v per cell.

Nigel

Nigel

that is good information to know from now on I will only put 4 propped bird in the air with a full charged battery thank you for that information