Just lost pro 3 in the ocean.

[Wolverine750]

Very sorry about the loss Paul, but as far as water goes, nearly any good flying area will be treacherous. The water, the mountains, snow...

Have the wife read some of these and let her know that we love the adventure of the drones, where we take them and where they take us. They are by no means toys. They are a life adventure thing.


Sent from my iPad using PhantomPilots mobile app

 

[MrFus]

1.- The algorithms used for calculation of battery capacity (as percentage of charge at the moment) are not perfect, and the firmware will return data that is erroneous rendering low voltage failsafes useless.

2.- We should never assume that a reading of the current status of the battery its 100% accurate, always charge battery to it's full capacity before any flying.

 

[Mark The Droner]

...His battery was at nominal operating voltage at takeoff.

....

This statement is completely and utterly wrong in every sense. You would know that if you read the thread. I suggest you read the prior 13 pages of the thread, and then comment.

 

[AJAX-14]

This statement is completely and utterly wrong in every sense. You would know that if you read the thread. I suggest you read the prior 13 pages of the thread, and then comment.

I read the entire thread and I'm looking at the log, 15.837V, 3.8V/cell at TO. That, by every definition in electrical engineering theory, is nominal for a 15.2 "rated" battery. You can continue to try and make that the argument, but that isn't the argument.

The net-net of the entire thread should be, always take off with a 100% charged battery. DJI is clear on that.

 

[Vertigo]

I just downloaded the CSV to get all the info; until now I was just looking at the summary generated by healthydrones. From the summary I thought it took off with 3.6V which could never correspond to 50+%. But from the csv its clear he took off with ~3.85v per cell (on the ground, no real load), which could well be in line with 56% capacity.

So there are several problems here; if we assume the voltage readings to be correct, then the battery drained way too quickly for some reason. The most obvious explanation is a faulty battery. Bad batteries happen, thats a fact of life, but that would still be a DJI problem. The only other explanation I can think off is a short somewhere, leading to excessive power draw.

The second problem is much more crucial: the battery state estimation clearly doesnt handle a bad battery or excessive load situation. It appears to rely on a calculation that takes initial battery state before take off (no load voltage) , then deducts measured (or estimated) current draw. That only works if your battery condition is good and known. But regardless of the actual algorithm, or if the root cause was with the cells or an incorrect voltage reading, if you are reading ~3v from all cells, the software simply has to know there is an urgent problem (and that capacity could never be >50%). There is no excuse for not handling this (and taking off with a full battery will not always prevent it). Most RC pilots will have those $3 lipo alarms that will beep if any cell drops below 3.3V:

That a ~$1K RC craft lacks this most basic protection is beyond me. Stop calling this an intelligent battery, its an utterly retarded one.

 

[Mark The Droner]

I read the entire thread and I'm looking at the log, 15.837V, 3.8V/cell at TO. That, by every definition in electrical engineering theory, is nominal for a 15.2 "rated" battery. You can continue to try and make that the argument, but that isn't the argument.

....

I don't know how you can read the thread (and there are many others just like it) and not conclude that you're getting a false reading.

I'm going to give up on this one. Bye.

 

[Vertigo]

false reading of what is the question though. Its clear that the voltage and capacity % cant both have been right, but the voltage readings look quite plausible to me (and would explain the crash when they dropped to 3V per cell) Neither of those is true for the capacity reading, so that is almost certainly where the fault lies. The voltage is most likely an accurate reading.

 

[Numone]

It looks like dji has taken the responsibility of this flight and saying that I was at no fault. However they said because I don't have original proof of purchase they are not going to replace or give a discount on a future device. I do have once employee contacting management on Monday. Nothing is promised but hopefully I will get some relief. I get the hard spot they are in but this drone was clearly purchased and clearly had a issue. I hope they help with something.


Sent from my iPhone using PhantomPilots mobile app

Cant you get a copy receipt from your vendor and/or credit card company?

 

[WetDog]

I just downloaded the CSV to get all the info; until now I was just looking at the summary generated by healthydrones. From the summary I thought it took off with 3.6V which could never correspond to 50+%. But from the csv its clear he took off with ~3.85v per cell (on the ground, no real load), which could well be in line with 56% capacity.

So there are several problems here; if we assume the voltage readings to be correct, then the battery drained way too quickly for some reason. The most obvious explanation is a faulty battery. Bad batteries happen, thats a fact of life, but that would still be a DJI problem. The only other explanation I can think off is a short somewhere, leading to excessive power draw.

The second problem is much more crucial: the battery state estimation clearly doesnt handle a bad battery or excessive load situation. It appears to rely on a calculation that takes initial battery state before take off (no load voltage) , then deducts measured (or estimated) current draw. That only works if your battery condition is good and known. But regardless of the actual algorithm, or if the root cause was with the cells or an incorrect voltage reading, if you are reading ~3v from all cells, the software simply has to know there is an urgent problem (and that capacity could never be >50%). There is no excuse for not handling this (and taking off with a full battery will not always prevent it). Most RC pilots will have those $3 lipo alarms that will beep if any cell drops below 3.3V:

That a ~$1K RC craft lacks this most basic protection is beyond me. Stop calling this an intelligent battery, its an utterly retarded one.

This is a sort of well known problem. It's clear that DJI's 'intelligent' battery is only half smart - Garbage In, Garbage Out. Since we don't have access to DJI's algorithms or engineering staff, we get to make up stuff and the current consensual hallucination is that the battery is getting confused by something - the self discharge algorithm perhaps or the fact that the battery doesn't calibrate and the 'run down to some arbitrary level every arbitrary number of charge cycles' probably doesn't get done routinely and likely doesn't do what it's supposed to anyway.

So, pragmatically, it is recommended that you charge the thing completely. And keep it warm.

Cuddle up!

 

[HVDV]

I just downloaded the CSV to get all the info; until now I was just looking at the summary generated by healthydrones. From the summary I thought it took off with 3.6V which could never correspond to 50+%. But from the csv its clear he took off with ~3.85v per cell (on the ground, no real load), which could well be in line with 56% capacity.

So there are several problems here; if we assume the voltage readings to be correct, then the battery drained way too quickly for some reason. The most obvious explanation is a faulty battery. Bad batteries happen, thats a fact of life, but that would still be a DJI problem. The only other explanation I can think off is a short somewhere, leading to excessive power draw.

The second problem is much more crucial: the battery state estimation clearly doesnt handle a bad battery or excessive load situation. It appears to rely on a calculation that takes initial battery state before take off (no load voltage) , then deducts measured (or estimated) current draw. That only works if your battery condition is good and known. But regardless of the actual algorithm, or if the root cause was with the cells or an incorrect voltage reading, if you are reading ~3v from all cells, the software simply has to know there is an urgent problem (and that capacity could never be >50%). There is no excuse for not handling this (and taking off with a full battery will not always prevent it). Most RC pilots will have those $3 lipo alarms that will beep if any cell drops below 3.3V:

Vertigo, Beware that at lower voltages the internal resistance of the battery is much higher, so that on load the voltage drop is much larger, and if the drone has not flown for a while the battery is colder further increasing that internal resistance. DJI recommends that the battery is fully charged before flying to avoid explaining all the details of using partially charged LiPos. Also if one stores LiPos at too high a temperature, or at either too high or too low voltages causes the LiPos to permanently go to higher internal resistance values, further aggravating this situation, which is best avoided by never flying to low reserves of battery capacity.

That a ~$1K RC craft lacks this most basic protection is beyond me. Stop calling this an intelligent battery, its an utterly retarded one.

 

[moto_jw]

I fully charged the battery two days ago and flew it down to 64%..Then brought it out today and said well I should go ahead and finish off this battery. Thats when I took off. I hovered for about 10 seconds and then headed out over the ocean. I dont know exaclt how far out I was or how high. I would assume I was 150-200 ft high and maybe 250-500 ft out. when it fell. And it appeared to just lose all power. I did make sure it was locked in tight and I am always worried about that.

This is what worries me. I have seen several posts about drones crashing when taking off with less than a full battery. Doesn't seen right to me. I understand about voltage drops etc. but in this case the battery was over 60% charged

 

[Vertigo]

Took me a while to find your actual response hidden in my quote:

Vertigo, Beware that at lower voltages the internal resistance of the battery is much higher, so that on load the voltage drop is much larger, and if the drone has not flown for a while the battery is colder further increasing that internal resistance. DJI recommends that the battery is fully charged before flying to avoid explaining all the details of using partially charged LiPos. Also if one stores LiPos at too high a temperature, or at either too high or too low voltages causes the LiPos to permanently go to higher internal resistance values, further aggravating this situation, which is best avoided by never flying to low reserves of battery capacity.

None of that in any way excuses DJI's software to not report a critically low battery situation when any (and in this case, ALL) cells are barely above 3V. Let alone reporting the battery >50% capacity. This is as true when its freezing cold or if you are in a hot desert. Its as true if you have flown 10 short flights or none at all. Its as true if your battery is brand new in perfect condition or puffed and at the end of its useful life. At 3V its empty. The intelligent battery is smart enough to shut itself down at that voltage, but the software too stupid to warn the user, instead reporting 50+% Its a bug, a major one, no matter how you slice it.

for the record; Ive been flying with lipo batteries for nearly 15 years now. I know how they work. I know how to interpret voltages, voltage sag under load, the effect of temperature, wear, imbalance etc. If DJI wants to hide all that and present me with a single number to represent remaining capacity, thats great. But if that number is completely wrong, and leads to crash with no warning, Im gonna blame them.

 

[Oso]

The intelligent battery is smart enough to shut itself down at that voltage, but the software is too stupid to warn the user, instead reporting 50+%. Its a bug, a major one, no matter how you slice it.

As @WetDog and others have noted, this has been well known and widely reported for quite a while now. I think that most of us agree with you that the battery management and reporting system of the P3 needs improvement.

 

[HVDV]

Took me a while to find your actual response hidden in my quote:



None of that in any way excuses DJI's software to not report a critically low battery situation when any (and in this case, ALL) cells are barely above 3V. Let alone reporting the battery >50% capacity. This is as true when its freezing cold or if you are in a hot desert. Its as true if you have flown 10 short flights or none at all. Its as true if your battery is brand new in perfect condition or puffed and at the end of its useful life. At 3V its empty. The intelligent battery is smart enough to shut itself down at that voltage, but the software too stupid to warn the user, instead reporting 50+% Its a bug, a major one, no matter how you slice it.

for the record; Ive been flying with lipo batteries for nearly 15 years now. I know how they work. I know how to interpret voltages, voltage sag under load, the effect of temperature, wear, imbalance etc. If DJI wants to hide all that and present me with a single number to represent remaining capacity, thats great. But if that number is completely wrong, and leads to crash with no warning, Im gonna blame them.

I agree that the software should warn about low battery voltage on load. However you also need to monitor the lowest cell voltage while flying. Since I also fly RC planes I often measure the internal resistance of each cell as a warning when batteries have deteriorated significantly due to storage.

 

[Wolfiesden]

The biggest issue is not the battery charge per se - it is the combination of a low charge and the time the battery has sat around trying to be 'intelligent'. It appears that the P3 gets confused at times an thinks a partially discharged battery has more power left than it really has. Unfortunately, you're in the air when the voltage goes critical (as in the OP's case) and then you're rapidly not in the air.

The OP was courting disaster when he hit the door. Going out over a beach with a low battery is going to get you in a number of ways. The aformentioned confused battery and a good wind pushing the bird out when you're trying to fly back in. Plop.

And I strongly agree with the other posters concerning the Inspire. Yes, they're very nice. They can even be had at a good price these days. But if losing a Phantom causes rending of garments and gnashing of teeth, think about what crashing out the bigger UAV is going to do to your budget. The low end Inspires don't have a better camera. They don't have better flight times. They can handle winds better - although I've flown the P3 in 30 mph winds, got some great video and lived to tell the tale. They're bigger and harder to haul around. Batteries are expensive.

Yes, they're cool looking. But once it's a couple hundred feet in the air you can't see it anyway.

There are obvious downsides to the Inspire series. Yes, they are bigger. That means weight and size to transport, store and also affects where you can fly reasonably.

Weight is another issue, it weighs way more than a P3. Obvious if you have to pack it or carry it any reasonable distance.

Batteries, yep they cost more and provide about the same flight time as a P3.

However, looks aside there are some advantages of an Inspire.

1. It has an interchangeable camera/payload system. The camera can be chanced out for others based on what you need to shoot. For example standard 4k camera can be equipped for day shots. An IR camera can be equipped for night shots. Some cameras have optional DSLR like interchangeable lenses allowing you to choose your zoom/FOV rather than being stuck at 94 degrees on a P3.

2. Dual pilot system. You have the ability, if desired, to fly dual controller mode. One pilot, one videographer. Not possible with a P3.

3. 360 degree camera rotation. With a phantom you are basically stuck looking forward. With the Inspire, you can aim the camera anywhere.

4. Unlikely to ever get props and legs in Inspire video. Quite likely to get them in Phantom video.

5. The inspire is faster and better equipped to handle higher winds than the P3. Its got bigger, stronger motors and larger batteries.

6. The inspire appears to be more professional looking than a phantom. I am not saying the phantom can't be a professional choice. But if you set them both on the desk and ask your clients which one appears to be the more professional looking drone, I am sure most of them will look at the phantom as a toy and the inspire as a pro level drone.

I would love to own an Inspire. I simply can't justify it as a pure hobbyist. I have no desire to go into business shooting drone video/images. And frankly, despite the numerous advantages the I1 brings, its disadvantages and its price are a show stopper for me. Not saying thats the choice for anyone else, I am saying thats my choice.

 

[NuclearSpud]

Sorry for your loss, but I think you just identified the reason, if you were flying with a partially charged battery then most likely that is the reason, there are countless threads about this and this is why I always charge my batteries before I fly and even top off a battery even if I charged it the night before just to make sure. Never fly with a partially charged battery

Interesting you mention this, took mine out today and noticed battery was about 46% (battery life has done ~20 flights) 7:13 flight time, had not been used for 12-14 days and must have started the battery self discharge process, zipping around fine for about 1 minute into the flight had a message pop up "Propulsion output limited, aircraft mobility has been lowered" I missed seeing this first one and at 4 minutes it appeared again I immediately did a return to home and once within arms reach hovered down to critical for a full recharge, I will look into the logs some time to see if it is an individual cell causing this maybe lower from the auto discharge process than the rest or something.
I like the advice Full Charge 95+% before every flight.

 

[Bobcatmo]

Stupid Noob question here:

With the intelligent battery, the battery will stop charging when completed. If the charger was left connected, would it start charging itself after the battery drops below "x" percent? Just curious, I have no plans on leaving the battery connected after charging, so no need to beat me up on procedures. I was just wondering.

 

[Hotwire]

I just flew my p3p out about 200 ft off the deck and over the ocean about 150 ft. It was doing great and then all of a sudden it lost power. It plunged into the ocean like I have never seen before. My heart skipped a beat. I saved and saved for this thing and eventually had to trade a truck to get one. It was too far out to swim for it. My wife is extremely mad and I'm hoping it washes up on shore tonight and I can retrieve it tomorrow. This post was really to let people know...it doesn't matter how much you trust your drone. If you want to keep it..don't go over water.

I would like to explain what happens when you fly past the low battery point.

LiPo batteries maintain a fairly high voltage until they are empty. Then, their voltage plummets very quickly.
The motors draw a lot of current, so the voltage lag from high current drain, is substantial. Once the voltage is too low to support the flight controllers minimum voltage (not the motors), all stops. This also applies to ESCs, so the low voltage alarm should never be ignored. It's not an option to continue!
Multi-rotor drones are totally fly by wire. If the electronics can't operate its a brick.

Sorry you lost your man-toy, but its a good idea to start cheap in this business and learn what goes wrong. They all crash for beginners, some sooner some later, promise!

 

[Vertigo]

I would like to explain what happens when you fly past the low battery point.

Here's what happens when you fly past low battery time: sometimes, for whatever reason, even though it measures critically low voltages, so low even the battery will shut itself down to prevent damage (yeah that really worked), DJI's software doesnt trigger a low voltage alert you and even incorrectly tells you your battery is still more than half full. Thats not something you'll learn on a cheap drone, because they dont tend to have this problem. A $3 lipo buzzer on the balance port, or simple voltage telemetry would probably have saved any other drone under the same circumstances.

Please stop making excuses for DJI. Most of us understand lipo batteries well enough, thats not the issue here, the issue is a glaring and dangerous software bug. This should be fixed ASAP.

 

[MrFus]

Let's stop beating a dead horse here gentleman... The truth it's that the "intelligent" power management firmware have some flaws and sometimes will not perform as it should be, on the older FC40 and some other quads small low voltage alarm modules can be installed and will avoid the dangers of flying with an unbalance LiPo pack, one with a damaged cell that will fail at mid air, or one almost depleted...

I don't own a P3 so I'm not sure if there is a way to install one on the proprietary battery packs from DJI...

If I was the OP and after saving hard hard to get a P3 see it gone because I take my chances flying with a partially charged battery last thing on my mind will be to put $1999 on a more advanced model!