Power failure during hover

[Ameila 1]

Working in a wheat field last week, winds were 5-10, with gust, so I kept the drone low. I was impressed with how well the PP4 handled, and felt comfortable going to 200' for the last high overview shot. As I went into a hover around 200', the drone shut off, like a light switch, it suddenly became very quiet - except for the director standing over my shoulder who softly said "oh-ho....", and proceeded to very neatly drop straight down, perfectly upright. At about 100', and not due to any heroic pilot magic, it restarted. I immediately tried to save the day, attempting to pilot out of the freefall. The puff of dust about 300' away let me know I failed, and, gave us a crash site location. Camera and gimble toast, rear support legs bent. Drone checked out as good. After it's restart, even with me attempting to give it "...full throttle up", I don't think it slowed down, the director with me does. It all took place so quickly.

The dealer and various experienced drone users have no idea why it had a power failure, and are even more puzzled on the restart.

Drone repaired, I was prepping for another wheat field shoot, I inserted a battery into the PP4, and it immediately started up on it's own. Now I'm a little spooked. The battery I inserted has a 50% chance of being the same battery as the in flight incident one.

If it is somehow pilot error, I'm good with that (expensive) learning experience, just kind of concerned. It might as well have been a brick falling out of the sky, it would have done serious damage to property not to mention serious maybe even fatal injuries if it hit an individual.

Thoughts, ideas or suggestions?

 

[Fly Dawg]

Thoughts, ideas or suggestions?

As a starting point, upload your .txt flight log to the link below. Instructions are in the link. After you upload, place a link back here to that and we can have a look to see what a cause may have been. You may have to upload the aircraft .dat file as well, but start here first.

DJI Flight Log Viewer

 

[Kirby Johnson]

First, sorry about your luck. And I usually do not follow routine drone crashes, they are so common, and they are usually readily explained once the flight data is examined.

Yours is certainly different, and I would be very interested in what the experts on here can deduce once your flight data is digested.

 

[Basspig]

I was reading last night about CSC's unintentionally shutting down the motors. That was the first thing that came to mind when I read this thread. But the restart is something I've not heard of. Very interested to learn what the logs say.

 

[Meta4]

I was reading last night about CSC's unintentionally shutting down the motors. That was the first thing that came to mind when I read this thread. But the restart is something I've not heard of. Very interested to learn what the logs say.

Accidental CSC isn't an issue for the P4 pro - it doesn't happen.

 

[Fly Dawg]

There have been several power loss instances with the P4's due to the battery becoming dislodged, but a re-start I can't see as something that would be that particular issue. Without seeing the logs everything is pure speculation. With that in mind, even if the battery had become dislodged and then somehow re-connected, it would be like starting over, which would mean that the full power up sequence of the aircraft would need to be completed prior to a motor re-start. So in this particular case, this seems highly improbable.

 

[Techcop50]

As was mentioned in a previous post, both my original batteries (extended capacity) began to swell, so I removed them from service. Out of curiosity, I decided to plug them in my P4P one more time to see how many times they have been recharged. What I noticed then was how difficult it is to get a solid lock on both upper and lower clips, on the swollen batteries. You can actually slam them in and the bottom clip would still be unlocked. I wouldn't be surprised if they unlocked themselves in flight, just by swelling.
And the usage was 27 and 33 times, btw.

 

[Basspig]

Aren't LiPo batteries supposed to be good for hundreds of charge cycles? 27-33 cycles for a $170 battery means that each flight is costing $5.60 worth of battery life.

 

[Fly Dawg]

Aren't LiPo batteries supposed to be good for hundreds of charge cycles?

In theory, yes. Swelling occurs occasionally, normally due to improper charging and/or discharging, but occasionally from simply bad cells. Like most anything else, you can get bad batteries that are not up to par.

 

[Basspig]

These batteries say that they are made in Japan, not China, so I would expect the quality to be pretty good.
My suspicion would lie with improper use and charging. Racing in hot temperatures, then slamming them on the charger, storing in a hot automobile in the sun, etc.

 

[Techcop50]

I have 5, only the two "premium" P4P ones have shown issues.
All bought from DJI website. All about 18 months old.
The standard capacity batteries are fine.

 

[Basspig]

What are the batteries sold with the P4P 2.0? Are those 'high capacity' or standard batteries?

 

[Paul2660]

The battery with the Vr 2.0 is the same as the P4 Pro, totally interchangeable, and same part number. Only difference I know of is the inner clip with a sensor that if not fully pushed down, the drone will not take off as you get a no battery error.

Part is a plastic spring clip with a contact. Over time this will odds are start to fail as pressure will not be the same, personally I just add a piece of gaffers tape to the top of the drone. When and if this clip fails due to normal pressure, it looks like adding something like a piece of paper or plastic will allow the contact to be made. A few new owners have already had to do this with "new" Vr 2.0 drones, so I don't see this as a great design feature.

Paul Caldwell

 

[Fly Dawg]

A few new owners have already had to do this with "new" Vr 2.0 drones, so I don't see this as a great design feature.

Agreed. This seems to be regressing instead of progressing. The P3's are normally rock solid. Only Pilot error on installation error would cause a battery disconnect.

 

[RunningWithScissors]

If this truly documented as a power shut-off and restart in-flight, it may well be the first reported here. Would be very interested in what the flight logs have to say.

 

[Fly Dawg]

If this truly documented as a power shut-off and restart in-flight, it may well be the first reported here.

Agreed. As I mentioned. Quite improbable that that occurred. That would indeed be an interesting look.

 

[RunningWithScissors]

I have 5, only the two "premium" P4P ones have shown issues.

Thanks for making that distinction. I've been checking my standard capacity batteries thinking there's gonna be a problem with them any day now. Guess I can finally get some sleep tonite.

 

[Kirby Johnson]

Agreed. This seems to be regressing instead of progressing. The P3's are normally rock solid. Only Pilot error on installation error would cause a battery disconnect.

To get a view of the big picture, consider the rough and tumble life a rechargeable drill like a DeWalt or Ryobi endures. Compare this to serenely floating through the air taking snapshots.

Next consider the cost of one of these drills compared to a P4 drone

Finally consider how long the drill buying public would tolerate the battery falling out of a drill in ANY situation, much less when you have a piece lined up perfectly with one hand and the drill in the other and it decides to eject it's power source.

I suppose my point is, the DJI product is a software and technological marvel, but it appears they let the software writers do the mechanical design too.

Baaad Idea Wong Chow.

 

[Basspig]

LOL... I've had my Ryobi drill go dead on me while I was up a ladder, holding a sheet of plywood against a wall, ready to put in the first screw, after struggling to get that plywood up and in place!

I've also had a new Ryobi battery not take a charge after 3 charge cycles. I think I worked it too hard by using the drill to screw in lag bolts.

Drone batteries are under constant struggle. Just imagine that Ryobi drill running a 1/2" masonry bit into concrete for 30 minutes without stopping. It's really a 'swim or drown' situation--there's no letup until it lands.

 

[Fly Dawg]

You may be confusing your battery types here. Most ( but not all ) power tools of all kinds use either LI or Ni-cad batteries, Not Lipo's. The reason for that is maintenance. LI and Ni-cad batteries do not require the type of maintenance that multi-cell Lipo's do. Just throwing that out there for reference.