Fell Out of Sky - Total Loss

[dirtybum]

Yes, no indeed. ;-)
I have one of the trouble free drones. No issues.

RedHotPoker

Thats what i thought too RPH til this same thing happened to one of mine! Dont jinx yerself

 

[Mark The Droner]

...
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.

That makes perfect sense. That is, it makes sense until we look at the common denominators in all these crashes. The common denominators seem to be:

1) A fairly well-used battery - that is, a battery that is not new and not almost new.

2) Something less than a full charge.

We don't read about these crashes with new batteries that are partially charged or older batteries that are fully charged.

It seems a combination of a well-used battery plus a partial charge equals dramatic increased risk of a drop from the sky.

 

[syotr]

There is a discussion at the DJI forum. It seems that the Inspire is having the same issue even with new and nearly new batteries.
DJI Forum|The head-scratcher's battery tests and thoughts.

 

[flyNfrank]

tcope.....regardless of the situation, I'm sorry you had to experience something you should not have had to. Your issue and others just like it about make a person feel like there is more to what is going on then we may know about. When these type of events begin popping up out of nowhere generally happen for a reason. If enough people get upset over this, we will know in a matter of time what's up.

These things make a person wonder.

 

[tcope]

tcope.....regardless of the situation, I'm sorry you had to experience something you should not have had to.

Yeah, I figure it is what it is. I enjoy flying so I should expect to have "stuff" happen. Thanks.

The more I read up on the subject the more I think it's a problem with the auto discharge. I would agree with others that it seems like the system (drone, app, whatever) reports the battery at a moderate level but then simply cuts it off. To really guess at it, I'd guess that it turns off thinking it's still supposed to be discharging and the only way to turn off this discharge mode is to put the battery on a charger.

I can't come up with any good reason why a battery with 61% charge just turns off. I've flown batteries with 40% charge (landed, turned off, made adjustments and then flown again) with no issues. I suspect I've even landed and turned off at 20% and then turned on and hovered in order to drain down to 8%. Never any issues.

 

[alokbhargava]

Yeah, I figure it is what it is. I enjoy flying so I should expect to have "stuff" happen. Thanks.

The more I read up on the subject the more I think it's a problem with the auto discharge. I would agree with others that it seems like the system (drone, app, whatever) reports the battery at a moderate level but then simply cuts it off. To really guess at it, I'd guess that it turns off thinking it's still supposed to be discharging and the only way to turn off this discharge mode is to put the battery on a charger.

I can't come up with any good reason why a battery with 61% charge just turns off. I've flown batteries with 40% charge (landed, turned off, made adjustments and then flown again) with no issues. I suspect I've even landed and turned off at 20% and then turned on and hovered in order to drain down to 8%. Never any issues.

No, once you switch on the battery by pressing two times, it comes out of discharge mode. And that's what happens when you start flying, battery is never in auto discharge mode.

 

[alokbhargava]

No, once you switch on the battery by pressing two times, it comes out of discharge mode. And that's what happens when you start flying, battery is never in auto discharge mode.

Whole system turns off when supply to electronics go below a low level.

 

[tcope]

No, once you switch on the battery by pressing two times, it comes out of discharge mode. And that's what happens when you start flying, battery is never in auto discharge mode.

I understand that this is what is _supposed_ to happen. I think there might be a firmware issue that _perhaps_ turns the battery off if it was in discharge mode and not out back on a charger before flight.

 

[tcope]

No, once you switch on the battery by pressing two times, it comes out of discharge mode. And that's what happens when you start flying, battery is never in auto discharge mode.

Have you allowed your batteries to go into auto discharge and then used them prior to charging up completely after installing the last firmware?

 

[flyNfrank]

Yeah, I figure it is what it is. I enjoy flying so I should expect to have "stuff" happen. Thanks.

The more I read up on the subject the more I think it's a problem with the auto discharge. I would agree with others that it seems like the system (drone, app, whatever) reports the battery at a moderate level but then simply cuts it off. To really guess at it, I'd guess that it turns off thinking it's still supposed to be discharging and the only way to turn off this discharge mode is to put the battery on a charger.

I can't come up with any good reason why a battery with 61% charge just turns off. I've flown batteries with 40% charge (landed, turned off, made adjustments and then flown again) with no issues. I suspect I've even landed and turned off at 20% and then turned on and hovered in order to drain down to 8%. Never any issues.

The Hot Ticket for is to get with member "Laup". He currently is finishing up with setup that will read your data and it can show almost exactly what took place with the battery issue. I couldn't get him to share it yet which do to it not being 100% to where he wants it. I can't blame him in that kind of situation. But none the less, he would ask to see the .DAT file for that flight. And dropbox would be the common method to get that file to him, if that is what you chose to do.

I personally want the real truth to this recent battery issue come out. I think something in the firmware has been over looked, but we really wont know without technical facts.

 

[bobmyers]

I don't understand this discussion. No experienced RC plane or helicopter pilot would take his aircraft out to fly on a battery with anything less than a 100 percent charged battery. To try to make this a Firmware issue or something else, is searching.

All lipo or lion batteries have well known characteristics and one of those is the lower the voltage the faster it will discharge until the bottom drops out. At 3.4 volts per cell it is dangerously close to dropping out and it is time to be landing it. If you accelerate a partially charged battery at 3.4 volts per cell it will start coming down--

Why keep pushing the envelop and try to make the P3 do something that it is not designed to do -- To fly reliably on a partially charged battery.

The other issue that no one talks about-- The "Smart Battery" may not be so smart in sending accurate voltage telemetry base on yesterday's charge when the P3 was landed with 60% battery. So it is still reading 60% 24 hours later-- it might be, but we all know that it may be somewhat less that 60% even though the telemetry says it has that much left.

 

[Spikeymous]

Common sense, I might do a test with partial charge, but not start a mission. Kinda like taking off with your plane or car half full for vacation. Lipos may show 60% when you insert and look at it in idle mode, but once you punch it the cells may drop to ? Instantly. New rule always start out phantoms on fully charged, and with a properly inserted battery. Even though I think my phantom is really cool.

I still like the old Quadcopters I can fly with 10$ Lipos and plan missions with mission planner that cost only 300$. LOL

 

[RedHotPoker]

Of course there were words over it, they were not happy the info was leaked. But that is not the topic here. I just wanted to clarify what had happened. You can contact me privately if you have any other questions. Thanks.

The person who needs to be contacted privately about this matter,
Wouldn't that be @Tahoe_Ed? With a friendly apology, for the error of ways that was taken, that caused the sad breakup in the first place. As that small step, would be my first hurdle. ;-)

Not my call or business, just a kind thought, in the proper direction.

Thanks for the helpful info.

RedHotPoker

 

[RedHotPoker]

Thats what i thought too RPH til this same thing happened to one of mine! Dont jinx yerself

You may call me RHP!! Ha
I never do, fly by faith nor tempt fate, bro. So that's why I reiterated, charge intelligent flight battery before flying, & I always do a battery check, prior of my heading out. If they're low, put them on a charger and top them, bad boys up. ;-)

RedHotPoker

 

[TheRealNick]

Check my other posts but it takes a lot to figure out a lithium battery's state of charge when it is partially charged, it is easy to track from full charge. To do this would compromise other features, you would have to stress the battery quite a bit before each flight which would lower everyone's flight time and add additional components and weight. When you work closely on a product somethings you neglect certain things as unlikely. Like to DJI they probably figure no one will try to fly on less than a full charge.

One way to fix it would be to just lock out flight when people start at less than 95% battery...but then you take decision making away from people.

For the people worried about flying on the same day and same battery I would not worry about touch and go and such. But personally if I flew down to 50% I would consider that battery done if moving to another location. My own rule is if I turn the phantom off, that battery is getting charged before I use it again....

An example is I was flying with my kids and one got attacked by fire ants. I landed and turned off the motors and then helped my son. After he was safe I powered up and flew as normal...

Another example is at 60% it looked like rain so I landed and went home. A few hours later it cleared up, but when I flew the second time I used the other fully charged battery...I would not use the partially discharged battery...

Be careful with these batteries....

 

[Adil J]

Check my other posts but it takes a lot to figure out a lithium battery's state of charge when it is partially charged, it is easy to track from full charge. To do this would compromise other features, you would have to stress the battery quite a bit before each flight which would lower everyone's flight time and add additional components and weight. When you work closely on a product somethings you neglect certain things as unlikely. Like to DJI they probably figure no one will try to fly on less than a full charge.

One way to fix it would be to just lock out flight when people start at less than 95% battery...but then you take decision making away from people.

For the people worried about flying on the same day and same battery I would not worry about touch and go and such. But personally if I flew down to 50% I would consider that battery done if moving to another location. My own rule is if I turn the phantom off, that battery is getting charged before I use it again....

An example is I was flying with my kids and one got attacked by fire ants. I landed and turned off the motors and then helped my son. After he was safe I powered up and flew as normal...

Another example is at 60% it looked like rain so I landed and went home. A few hours later it cleared up, but when I flew the second time I used the other fully charged battery...I would not use the partially discharged battery...

Be careful with these batteries....

Good examples, I am so glad I saw this thread now. 2 days ago I had flown to about 40% charge then taken a 15-20minute car ride and had planned to fly again for another 10% or so. It was cold weather as well. I am thankful I didn't, it could have definitely gone bad. You learn something new everyday.

 

[alokbhargava]

Have you allowed your batteries to go into auto discharge and then used them prior to charging up completely after installing the last firmware?

I didn't dare to take that risk


One thing I have noticed that if you leave the battery say at 50% on one day and next day you try, it shows higher voltage but the moment you load it voltage collapses. I will try it again to establish the fact. I had noticed it by chance and stopped the motors immediately.

 

[yawnalot29]

DeoxIT® Gold G100L, Squeeze Tube, 100% solution, 2 mL,
(Applications = 50 +/- drops, 0.04 ml/drop)

Part No. G100L-2C (2 mL)

DeoxIT® Gold G100L Mini-Brush Applicator, 100% solution, 1.6 mL
(Applications = 100 +/- brush strokes, 10mm long)

Part No. G100L-16BX (1.6 mL)

Man, this hobby is like money pit! Here I was, just reading and enjoying the forum, and bam, I saw this and I am out $20 on Amazon!!

Anyway, this got me intrigued and I came across this review:

Amazon.com: JustAnotherEngineer's review of DeoxITGOLD Liquid, Brush Applicator - Meta...

 

[tcope]

I didn't dare to take that risk

Then you are only repeating what _should_ be. You don't know that it's what is correct. You can repeat the manual all you want... real world experience is something different.

 

[kphantom]

So a battery should turn off in flight if it's at 60% charge?

Part of my issue was that the batteries were charged at 100%... it's just that the auto discharge had kicked in and I did not realize it. I do understand alokbhargava's point... if this _is_ an issue, then it should be addressed by DJI. It it comes down to the fact that someone should never start flying at less then 100% battery then a simply solution would be to either install a warning or lock out the flight. There are warnings for other things, such as lack of GPS signal.

Hmm. I wonder if auto discharge activates when someone is flying? It seems that might be a big issue!