Fell Out of Sky - Total Loss

[Volantis]

I hate to nit-pic, but these are not really lithium ion batteries.

I doubt you really hate it.

There is nothing wrong with being right. I wouldn't mind reading a technical paper on these batteries if you know of any.

 

[tcope]

This seems to be the crucial factor.
Somehow a battery which is part way through auto discharge is DANGEROUS to use.
If you take off having part used the battery in flight a few hours before it's *probably* OK

That would be my best guess. I have flown before with batteries that were under 100% and had no issues. Let me mention, I almost always start at 100% but sometimes I'll land with that battery, turn off the battery and then start back up. Never had an issue. To my knowledge I've never started up a battery that had just been in a discharge cycle. Might be time for some controlled testing with video.

 

[tcope]

I have had a partially discharged battery give me critical warning at over 50% charge.
Also from the healtydrones site your cell 3 is 0.5 volt down which is not good.

There can be some difference and that is not much. Also, I suspect it might be an incorrect reading due to the quick shut down. I always upload my flights to healthydrones and while I've seen small differences in that battery, none showed any big differences.

 

[wbynum]

People are going to make mistakes. For a quad that wants to hold your hand in every possible way it's rediculous that it just shuts down instead of draing the battery. Killing a battery is much safer and cheaper than the quad dropping from the sky.

 

[phantom13flyer]

I think this can be easily tested on the ground with the props off using batteries that have begun auto discharge. I currently have 2 batteries that might this requirement and 2 that I manually ran down to 50% but I won't have my bird back till Wednesday or Thursday . I'm having a bird side video amp installed. But if no one tests this theory by then I am more than happy to do the test.

 

[tcope]

I don't understand this post. If the manual says to be sure your battery is fully charged before every flight, doesn't that qualify as a REASON not to use a partially discharged battery?

Usually this is mentioned as the manufacture does not want people trying to fly with super low batteries, such as 12%. What about 98%? What if you fly for 1 minute, pull the battery and put it back in at 80%?

And if not, what about the DOZENS of threads from pilots who have lost their crafts due to batteries abruptly shutting down? What do they all seem to have in common? Partially charged batteries!

To me it would then seem like a defect. A person _should_ be able to fly with a battery that is more then 50% charged.

Personally, I think it might be more likely that there is an issue with using a battery that was just taken out of discharge mode... not just that it's less then 100%.

It doesn't really matter whether it makes sense or not. What matters is that we stop tempting fate and do what DJI suggests.

I've read the threads about not flying with batteries at less then 100%. In my case I had charged the batteries up to 100%.... I just did not realize that I had let them sit for a few days. I had just bought a 4th battery so the expense was adding up. I wanted to do all I could to preserve them so I turned down the auto discharge to 3 days. I _did_ realize before I flew that the batteries had auto depleted and I chose to fly anyway. I figured 60% was charged enough that a low battery was not an issue. It appears that I could have been incorrect. I can live with that. What I'd value more is if this perhaps puts us all closer to understanding what _might_ be the real issue... flying with a battery just out of discharge.

 

[phantom13flyer]

I agree the problem does seem to point toward not using a battery that has begun auto discharge.

 

[tcope]

Sorry to the OP...but completely user error. Not a DJI issue.

Taking off in 32 degree (F) or less temperature, with a battery at 61%, no warm up, then straight to 40+ feet altitude.

Can't believe people want DJI to do something about this "issue"

If 32F degree weather is a user error, why does DJI specifically list this as the operating temp for the P3? Also, the weather was 32F, not the Phantom. The Phantom had been sitting in a vehicle at 72F and was only outside for 5 minutes. Part of that time was allowing the IMU to warm up as required. I was in a parking lot about 50' away from 2 people and 40' was a safe altitude to hover as I wanted to check my settings. When have I _ever_ mentioned that I wanted DJI to do something about "this issue"?

The information in your post is very incorrect.

Edit: Unless the "issue" is that batteries turn off in flight because they were started up from a discharge. I've never blamed DJI for the crash. What I'm much more interested in is if this leads to some better understand as to why P3's are just suddenly turning off in mid-flight.

 

[tcope]

I'm the battery expert, so listen to me. I assume this was stock battery, the one you had for approx 6 months? How many times did you charged it and what was the battery health?

Sorry, I missed this post.

That battery has a total of 43 charges on it.

I can't speak specifically for that battery as I've had 3 for a long time and use several each time I fly. While they are numbered, I don't know which log that day is for which battery. But I can say that I upload my logs and review them pretty much after every flight. I've not seen any errors with any of the batteries. If a battery is above 20 flights I do take it down to 8% as recommended.

 

[TrynFlyn]

If 32F degree weather is a user error, why does DJI specifically list this as the operating temp for the P3? Also, the weather was 32F, not the Phantom. The Phantom had been sitting in a vehicle at 72F and was only outside for 5 minutes. Part of that time was allowing the IMU to warm up as required. I was in a parking lot about 50' away from 2 people and 40' was a safe altitude to hover as I wanted to check my settings. When have I _ever_ mentioned that I wanted DJI to do something about "this issue"?

The information in your post is very incorrect.

Edit: Unless the "issue" is that batteries turn off in flight because they were started up from a discharge. I've never blamed DJI for the crash. What I'm much more interested in is if this leads to some better understand as to why P3's are just suddenly turning off in mid-flight.

I understand your position. I'm just saying that I disagree. Taking off with a battery at that charge level in that outside temp and going to that altitude is / was not a wise decision.

I also didn't say you wanted DJI to do something about this issue - I apologize if I implied you did.
Other comments in this thread have suggested DJI should.

 

[Dome]

I don't understand this post. If the manual says to be sure your battery is fully charged before every flight, doesn't that qualify as a REASON not to use a partially discharged battery?

And if not, what about the DOZENS of threads from pilots who have lost their crafts due to batteries abruptly shutting down? What do they all seem to have in common? Partially charged batteries!

So there are two good reasons.

The reason is that they know a problem with "intelligent battery". So becouse they state on the documentation use full batt it's better to follow their raccomandation but to me it doesn't explain nothing technically significant. They can always say "I've told you..."

 

[syotr]

The battery problem will be fixed in the Phantom 4.

 

[WetDog]

There is NO firm evidence that this is the problem!
What about a battery that is at 97% or 98%?
I ALWAYS charge mine up but I dont think you will do a battery any favours trying to get that last drop of power into it.
There do seem to be a higher than average number of these crashes happening at say 50% charge but this isnt proof. DJI should sort this out. Why does the battery have to be "intelligent"? Surely losing power gradually so you can just bring it down is preferable to a sudden switch off and drop?

I THINK (YMMV, do not try this at home, Do Not Taunt Happy Fun Ball) that the issue is the Phantom / battery 'intelligence' is not so smart when it comes to a battery in anything other than a fully charged state. There is likely enough power in the battery to perform the task, the system just can't figure out how to use it and doesn't exit gracefully.

So, it's not that you need the extra 3% to go from 97 to 100%, it is just that charging the battery to whatever the system thinks is complete puts it in a 'known good' state. The Phantom's happy place, if you will.

DJI should be able to fix this. Eventually. But for now, I'm going to run on batteries freshly out of the charger. Batteries are cheaper than the drone.

 

[WetDog]

The battery problem will be fixed in the Phantom 4.

Probably. And the new bird will introduce a couple of dozen NEW problems.

Welcome to the future.

 

[SteveMann]

I use DeoxIT Gold on all my electrical connections other it be my UAV's, RC crawlers, my DSLR, etc. Well worth the few bucks for the tube as a little goes a long ways. I haven't owned my P3 for long and I have had zero issues so far. I have however flown my P2 for two years, also with no problems and I have used partially charged batteries.

Which version of the Deoxit product do you use? Pen, brush or bottle?

I really don't see how a partially discharged battery could cause any of these incidents. If there is enough battery to take off, then all that would happen if the battery capacity drops in flight is the aircraft would go into a fail safe landing.

I believe that all of these "sudden power loss" complaints is the battery connector disconnecting for less than a millisecond. That's all it would take. Everything goes dark as the controller processor reboots, but the aircraft is falling out of control and hits the ground before the processor can restart. In my 3DR Hex the controller can be powered separately from the motors so that a momentary power loss to the motors would not cause a processor shutdown.

 

[alokbhargava]

The battery problem will be fixed in the Phantom 4.

Who gave you that info? Does DJI believe that P3 has design problems? Why would they improve if there are no problems?

 

[alokbhargava]

Probably. And the new bird will introduce a couple of dozen NEW problems.

Welcome to the future.

Very true.

All current issues are listed for future resolution,

..Stress cracks on shells
..Major vibrations
..Sudden death of P3 during flights
..Unpredictable batteries
..Scary battery internal wiring
..Props flying off
..Bad software installers, need downgrade and upgrade
..No site where known issues are listed and ETA from DJI is committed
..many more

 

[rotax91]

Yup. Don't usually do it. But does not justify entire power loss. I'm not blaming anyone.

It might just only a theory but as well as myself and someone I personally know but it seems to be the pattern. He flew his, shut it off and went to another location and took off again. That's when it dropped out the sky. I don't practice flying with a partially charged battery. I ran all mine down to roughly 50% since I wasn't gonna be flying for a week. A few days later there was a house fire a few blocks down and I wanted to capture it on video. I put the partially charged battery in thinking it would be ok for a couple minutes. It dropped out of the sky within 10 seconds after taking off. Complete power shutdown. When I got to the crash site, I tapped the battery button and it had 2 full green LED's which would indicate roughly 50%. So if this theory is true, I'd like to know what the difference is between a battery that was run down from 100% to 50% vs one that was sitting at 50% for a few days.

 

[alokbhargava]

It might just only a theory but as well as myself and someone I personally know but it seems to be the pattern. He flew his, shut it off and went to another location and took off again. That's when it dropped out the sky. I don't practice flying with a partially charged battery. I ran all mine down to roughly 50% since I wasn't gonna be flying for a week. A few days later there was a house fire a few blocks down and I wanted to capture it on video. I put the partially charged battery in thinking it would be ok for a couple minutes. It dropped out of the sky within 10 seconds after taking off. Complete power shutdown. When I got to the crash site, I tapped the battery button and it had 2 full green LED's which would indicate roughly 50%. So if this theory is true, I'd like to know what the difference is between a battery that was run down from 100% to 50% vs one that was sitting at 50% for a few days.

There is a difference.

P3 FW knows how to compute the remaining charge at any point if started discharging at 100% charge. Discharge curve is not linear and needs good onsite into batteries. It's unable to compute if you start, say at 51% and is therefore unable to initiate fail safe mode. The net result is fliers are questioned for not taking precautions. Who doesn't make a mistake but that should not result into total crash of P3. System should generate enough alarms and initiate corrective actions before worst happens.

 

[WetDog]

Very true.

All current issues are listed for future resolution,

..Stress cracks on shells
..Major vibrations
..Sudden death of P3 during flights
..Unpredictable batteries
..Scary battery internal wiring
..Props flying off
..Bad software installers, need downgrade and upgrade
..No site where known issues are listed and ETA from DJI is committed
..many more

Laser range finder (or similar tech) to determine Altitude over Ground instead of relative altitude over wherever you started from. That is, a brief lesson in geography for DJI - the world is not flat.

Bonus points, lots of bonus points, for a retrofit to the P3.