I posted the flight log to helathydrones.com. Any insight / feedback is appreciated.
http://healthydrones.com/main?flight=f8a564fde9728351b18b269c70dde0a6&page_id=POWERBattery_Cells

I did several flights yesterday with no issues. The P3 was working perfectly. I'm a forester and use it for reviewing cutblocks to assess the status of reforestation, as far as I know I'm one of the first people in British Columbia to use a drone for this. I charge the batteries in my truck while I'm driving to the next cutblock and generally have not used a battery <60%. They charge up pretty quickly so ususally it's not an issue.

This morning I didn't have fully charged batteries and I popped in a battery that was 49% thinking this was fine for a quick look at a block. I fired up the P3 and took her up and away, then suddenly (17 seconds in) I heard the engines shut off. Fortunately  the craft was only a couple hundred meters from me and I heard the engines try to come back on but it was too late, it crashed from about 70m height. The app said no signal from the time I heard the engines shut off and I didn't get a signal back. Fortunately I was able to see the flight path and recovered the drone and broken off camera. The gimbal arm and flat wire are broken and as far as I can tell, I can't order these from DJI (have to order the full camera and gimbal assembly). The other broken parts I can get from DJI. The drone still connects to the RC and appears to work fine but the wires are all torn off so no connection to the app. I'm not even looking for warranty since it appears I would be without the drone for months and I want it back for work. It was working so well!!!

I would like to know what happened and warn others not to fly without fully charged batteries. I read another thread on here about a 40% battery doing the same thing, everything fine at takeoff but suddenly shortly into the flight sudden power failure. I'm wondering if the battery I used is faulty or if I should not have flown without fully charging it. I have 3 batteries and haven't had a problem with any of them until now. Another thing I will do in the future is hover a couple feet off the ground for 30 seconds or so from now on before taking her up...
Thanks for your insights!

Man you got to look at the voltages before you fly.....  never ever fly on a used battery, it has to be 100% full charge and that 100% has to be with in 12 hours or cells start to loose the balance.
The healthy drones log shows the battery cells were clearly below 3.6 which is the minimum or in my case is the dead battery level, they were 3.4 and 3.2 volts, i think this battery has been damaged with no turning back.

Willie Wonka Posted at 2015-10-6 19:54
Man you got to look at the voltages before you fly.....  never ever fly on a used battery, it has to ...

Ok, good to know. Wish I'd known that.

I just charged the battery and it went to 98% and 4.32V in all cells except for one at 4.31V. Is that acceptable?

Thanks.

interfaceforest Posted at 2015-10-7 00:23
Ok, good to know. Wish I'd known that.

I just charged the battery and it went to 98% and 4.32V in ...

That is what you need to be at when you start flying and a minimum of 4.28 volts per cell, the problem is these cells don't keep a charge for long, so some sag more than others, which results in all cells not being equal. when flying with a weak link it brings the whole group down, and when one cell is weak then it starts to discharge a lot faster than the others, thats when the controller sends an alarm to shutdown everything.

I would keep an eye on cell #1 of that battery, and all the cells for that matter.
The deviation when you were using the P3  was .095v, and that was from cell #2......with additional deviations of more then .01v between that and the other 2 cells.  
While that could be the result of using a battery that starts out at 49%, when you get flying again keep an eye on the cell voltage when you turn on the P3, when your in the air, and after you land.

If there is consistent deviations of more then .01v between cells there could be a real battery problem.

interfaceforest Posted at 2015-10-6 23:23
Ok, good to know. Wish I'd known that.

I just charged the battery and it went to 98% and 4.32V in ...

Make sure you have display voltage on main screen toggled on.  Watch that as much as anything else.

So every time I read about a full battery I wonder about this:  Suppose I start with a full battery, fly it down to 60%, land to change a lens filter and want to take off again.  Am I safe to take off on that 60% battery?  If so then why isn't it safe to just put the battery in at 60% and take off with it?  Not trying to be difficult, just trying to understand.

bill@northwoods Posted at 2015-10-7 08:28
So every time I read about a full battery I wonder about this:  Suppose I start with a full battery, ...

Probably because it is different using a stored depleted battery than one that was fully charged 10 minutes ago but you just landed and the  battery is still warm.  These batteries will lose their punch if not used right away.   If I miss a day with a full battery,  I turn the battery on before I go out and fly next time and plug it into the charge and wait for it to fully charge again.  Like the manual says.

There have been too many recent reports of Phantom 3's dropping out of the sky for no apparent reason.  One recent post from an owner shows how a faulty solder joint on the battery controller board caused a battery to fail after only 7 charge cycles:

http://forum.dji.com/thread-32663-1-1.html

I suspect DJI is having a quality control issue with the solder joints in batteries.

Very helpful series of input.
I think most of us - me anyway - always considered batteries as plug and go. That said, according to the accrued knowledge of 'how to use'.
Although the same her, the 'how to', deviates from earlier forms of batteries in the type, tolerance and demands.
Cell balance, voltages, demand for amperage, heat and its effects can play a role that, in our cases at worst means a smashed UAV and third party damage.

So my absorbing the experiences relating to power supply is not any longer to maximise the term of usage (years) a battery might last, but whether it will be responsible toward al aroundl, including myself, to use it - knowing the thing I'm using!
I confess that I'm not quite 'there' yet in regard to batteries, but this is expected from every one who will be called upon to 'do something with that drrohn' (called komerz) - It's written flight checks and logs - which battery used, data pertaining to it.Basically, we all need to have the run of this in our approach to the vehicle, simply because that appears to be its nature.
It goes in the air, and stays there courtesy of 'The Creator', laws of reciprocation embedded in the manifestation (creation) and... don't laugh (or do-or both)
DJI - thanks all you nutty geeks and competent machinists and much more -
so I thank the source of my 'be'ing - also 4 dji, the forum, all of us and all things -
* whilst learning not to be the source reason for my complaint! *

Love and laugh to all




Oh: Keep 'em in a fireproof box or special bag - 20-25c is around fine. Don't throw 'em in a box or shove them around, and the fridge is not an advantage.

Welcome to the club.  :-(

Here's a link to my post-mortem... http://healthydrones.com/main?flight=640d858faaf731df0b4e211d0dc269bc&page_id=POWERBattery_Cells

All in the green, and it still went AWOL and is now at the bottom of a lake.

It seems like there's way too many of these "drop out of the sky" issues going on.  Now that it's happened to me, I see all sorts of posts about them.  If there are known issues about "what not to do" (tm), then DJI would have to take some ownership of the problem and have their DJI Go app issue clear warnings to the user.

Bluevista Posted at 2015-10-7 15:07
Welcome to the club.  :-(

Here's a link to my post-mortem... http://healthydrones.com/main?flight=6 ...

Upon looking at your log i found two things :

1 - you were aggressive with the drone as it flew 845 feet in less than 35 seconds .
2 - your battery was very unstable on all cells, as deviation was on all cells.

So to sum it up, one of the cells got too weak in your case and made the phantom collapse mid air. And i guess you had the battery charged two days before you flew ?

Willie Wonka Posted at 2015-10-8 05:00
Upon looking at your log i found two things :

1 - you were aggressive with the drone as it flew 8 ...

That's correct about the battery charge.  This was on a morning of a Boy Scout overnight.  I believe I took it off the charger on Friday eve, and flew it Sunday morning.

I didn't think I was overly aggressive with the throttle.  When I do the math, it comes out to about 16mph.  What speed would considered non-aggressive?
BTW: I appreciate the extra eyes on the log.  Thanks.  If you're curious about the context of the flight, I posted the bulk of my problem ticket on this thread... http://forum.dji.com/thread-32640-1-1.html

Bluevista Posted at 2015-10-7 13:07
Welcome to the club.  :-(

Here's a link to my post-mortem... http://healthydrones.com/main?flight=6 ...

Way too many??? If you search real hard you might find 10 but I doubt it. 10"s of thousands of Phantoms out there so I wouldn't call 10 way too many.

QaaUz Posted at 2015-10-7 12:00
Very helpful series of input.
I think most of us - me anyway - always considered batteries as plug a ...

QaaUz-  You, sir, are very articulate with very interesting phrasing,  I find myself getting  "more intelligent" just by reading your words, are you, Perchance,  an Author?



Jim

Something i noticed in  logs, is the battery temperature.
You take off at about 59F, which is pretty low for a Lipo. In Lipo's,

Colder temperature rises Internal resistance and Dropping voltage..

CaveDrone Posted at 2015-10-8 00:44
QaaUz-  You, sir, are very articulate with very interesting phrasing,  I find myself getting  "mor ...

I thank you most kindly. I do indeed 'pen' the inarticulacy that masquerades as communication - now you see how absurd words can become, yet surely needed not the reminder
My seeming inability to maintain attention has precluded the ultimate utterace known as book, article and the likes of such.
I've lived among differing cultures and was also taught the value of the word - as opposed to that of the sword - ah, indeed it is/was, that the power of the word is mightier than the sword. But then I'm certain the thought is not new to you.
Thankyou for the kindness of your approach. I hope the substance of my comments may mainly be of help and or a contribution to the well being and equity amongst us all - as a whole -thus affecting indeed ALL. How delightful indeed.
Greetings. -raises the hat

QaaUz Posted at 2015-10-8 02:11
I thank you most kindly. I do indeed 'pen' the inarticulacy that masquerades as communication - now ...

addenum:
and the comment I make that do not, that I may 'humbly' respond appropriately to the aforementioned 'goal.
'umbly yer fella servant.

Copterpilot Posted at 2015-10-8 00:47
Something i noticed in  logs, is the battery temperature.
You take off at about 59F, which is pretty ...

You know all this is fascinating.
I read, a pilot took off, the temp was minus 6 - C I guess - it was today I saw - phantompilot forum or here - can't remember.He caught an incredible sunrise - he said, I've got 5-10 minuites if I'm lucky. Bingo Phantompilots in regard testing Rainbowers ND filter set (magic set - got that here) - so you can check it up and correlate. Early, sudden, temp, demand and so on.
These batteries may be 'fragile' or need some awareness, but folks are fliying in the arctic, in probably hot areas which I'm glad not to be sweating in and so on.
I would suggest a lack of panic, accusation and the various we stumble across in favour of the overall picture we might begin to see emerging.
I see nothing clear apart from this. Check-Kontrol! Procedures learned from participation in the communal teacher/student-experience sharing participation of this and other forums and social contacts as per ones own tone of interaction - But in relevance to batteries=Power source. Juice - the stuff the likes of, running out of means get out and push -
Sorry I forgot, its a P3 forum - it crashes from the sky, buries itself at the bottom of a newly forming sinkhole that has eluded GPS Glasnost, Glanoss OK.
No panic = digest the learning.
To bravely go, where no....
groan

I am happy to have become a member here. I am learning A LOT!

theo54au Posted at 2015-10-8 02:35
I am happy to have become a member here. I am learning A LOT!

Just passing, so all the best mate and so've I
and Welcome.

I've responded to a number of incentives in this thread, and wish to come to you who originated it - late though it is here. I'm sorry you have the consequences of this experience - at least on the one hand. The other never knows the benefit hidden within the moments.
I too am mainly concerned with use in the forests/plantations though our landscape and scope of environment be very different. As your camera is gone, you are left without a tool you recently began the process of using, appreciating (so it sounds) leading potentially to the intuitive stage of a tools usage. Now that stops. Quite abrupt.
This is in reply to you, not really issue releated.
You may (or not) well agree that forestry can't be engineered also not from the air. We constantly learn, there are few of us to pass on points to watch for, tasks that, if done, improve the forest and thus the environment of mankind - it is very much an on the spot 'thing' for forest folks, and yet there are also great benefits from certain tools - how hydraulics has released us from a degree of physical harshness that was often damaging. It has also resulted in a wild orgy of forest destruction.
Just a word amongst those of the forest.
This, if any furtherance may neither suit you, I or the forum to remain on this thread.
Please accept this in the courteous manner my return to this threads originator and I hope my words indicate.
Cold times ahead - and warm cosiness.
best wishes and good flying/fotogrammetry - and good old fashioned fotos

QaaUz Posted at 2015-10-7 21:27
I've responded to a number of incentives in this thread, and wish to come to you who originated it - ...

Don't mind me but you look like gandolf the great ( from lord of the rings movie),  if this is your real picture.

Bluevista Posted at 2015-10-7 17:10
That's correct about the battery charge.  This was on a morning of a Boy Scout overnight.  I believ ...

I have been handling lip batteries for too long now, it is like second nature to me of when not to use a lipo.


Regarding the aggressive action, i forgot to mention that you went flying with high demand right away, it needs a minute to heat up on hover and then give it full throttle after, heating up in hover gives the cells time to even out and come closer to each other in voltages and at the same time give you time to see if the cells are stable and not dropping rapidly which can spare ALOT of money on the account of 1 minute of hover.

I on the other hand not an expert or a scientist, i have no gain in replying back with my personal opinion or experience, so please take my words as kind words not an intimidation or you did something wrong.

Sorry for your loss and also sorry for the OP loss and wish it don't happen to me, BUT it will happen sooner or later for any number of circumstances even if i did all the things i preached to you and to other, it is just a matter of delaying that moment.

Can you stop death ? nope.....

Willie Wonka Posted at 2015-10-8 03:46
Don't mind me but you look like gandolf the great ( from lord of the rings movie),  if this is you ...

That's one angle of me - no much for any photo of me - ha, but being a photographer artist etc I noticed a profile foto of a muso SC 'collegue and later the year (or so) I saw a mug shot of yours truly in a vid I was doing after getting piles of wood home from the forest. So a screenshot fixed that.
What the heck! As for Lord of the Rings, I only know of the name but have no knowledge of it. I guess we all look like someone else - It wasn't me - I didn't do it, as a now long gone friend used to grinningly say.
BTW, I didn't catch ya preachin' man - never been with such a nice growin bunch o folks - warms the heart.

QaaUz Posted at 2015-10-7 18:27
I've responded to a number of incentives in this thread, and wish to come to you who originated it - ...

Thanks to all who posted, your insights are appreciated and very insightful.

As for the utility of the quad copter as a  tool  in forestry applications, I'm finding it to be just that... A tool that is useful in certain circumstances. In my line of work,  mostly I'm finding it's useful in mapping problem areas where reforested tree density is lower in stands >10 years post planting. For these areas it's valuable for quickly identifying where more work is required to achieve adequate tree densities or where brushing is required to alleviate undesirable veg competition with crop trees. In BC, forest companies are legally required to reforest sites they've logged to set densities with ecologically appropriate species .

The drone is  not a replacement for walking the land but an aid to assist me to quickly identify where attention is needed. It also provides me with the means to show others who have not walked the land what's going on with the reforestation process on that site.