DJI may replace your P2, Inspire, or P3 if it crashed due to battery

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We have known about P2 smart batteries having a "sudden % charge drop" for some time.

Inspire folks have the same issue.

P3 folks have the same issue.

dji has done nothing to fix it as far as we all have been able to tell.

I finally have been able in the last few months to capture the fault and prove it appears to be a firmware error; it appears that grand "discharge to 8% every 20 cycles" is the culprit. I have captured it and it is very repeatable. A recent thread here had the sudden drop from 82% to the magical 8% recalibrate due to this routine in 22 seconds, causing autoland to initiate - way out over water. the operator amazingly brought it back in ATTI.

The data shows that a certain trigger (I believe about 11.08 or so volts IIRC - see my other threads with the data), all smart batteries from all dji models initiate this recalibrate routine. I have posted over and over for them to see, they need to add a line of code to NOT enter the recal routine - if motors are running. Problem probably solved.

Some of us have found other errors in the past in other areas and actually reported them to dji; result: they ignored us, said they could not find any issue, and even deleted some of the inof sent them. So I did not bother trying to report this one again, figuring dji dave and others actually read this stuff and would send it to the engineers..

Seems they may have! Over on dji forum, a person who has some contact with dji types, reports they are taking action on this battery issue, that the latest inspire fw is supposed to attempt to address it, and most important, if true, DJI WILL REPLACE ANY DRONE CRASHED BECAUSE OF THE BATTERY DROP ISSUE.

I strongly suggest any P2 flyer who does NOT have a logging app like Ultraflight, lichi, etc., they should get it immediately so they will have proof if this ruins their drone.

Here is link to the dji forum posts about it:

DJI Forum|The head-scratcher's battery tests and thoughts.
 
Great job
 
Awesome job
 
The thread links do more "back and forth" than a fiddlers elbow.
Or was that supposed to be "in and out"? ;-)

Anyway, I am of the practice, to charge my batteries back up to max capacity, before heading to my favorite haunt. Yeah, and so I don't have to worry my heart out, about this sort of stuff. Charge and fly.
Simple to check them and top em up. "Go" have areal thrills., no guitar, fret free.

RedHotPoker
 
Ok, so until a new firmware is made available, don't calibrate?

Remember this.......Could be sooner then you might think. :)

Super awesome work yorlik!
 
DJIs website says to call your dealer about warranty issues. I don't see B and H being much help with a smashed P3. Is there a better number to call DJI about this? I'm in the US.
 
So why are some reports coming in that after 140 flights, etc. the same thing happens...and why does it seem in most cases that it is with batteries not fully charged?

Thanks for any explanation. I'm one of those people who want to understand the gory details. I never fly without a full charge but your statements seem to suggest that would not help....it would just go into the auto-discharge cycle at 20 flights!
 
WOW very interesting and something to pay attention to. Good work Yorlik Not to change the subject but here lately two of my batteries with 80 or so charges on them and 93% life left are now hitting 3.3 volts under load and have to back off the throttle, it has got more noticeable, even 3.5 I'm starting to get uncomfortable with my reading. I did have an auto land when this happened once and luckily I was able to get it back in. Has anyone else been running into this?
 
WOW very interesting and something to pay attention to. Good work Yorlik Not to change the subject but here lately two of my batteries with 80 or so charges on them and 93% life left are now hitting 3.3 volts under load and have to back off the throttle, it has got more noticeable, even 3.5 I'm starting to get uncomfortable with my reading. I did have an auto land when this happened once and luckily I was able to get it back in. Has anyone else been running into this?

Jbundy, unless you have dyslexia, I would certainly recommend you NOT fly EITHER of those batteries any more - both are VERY DEFECTIVE!

Know that % life is a simple mathematical equation: 100* (300-CYCLES)/300

So if both your batts have 80 or so cycles on them, their life is 73%, NOT 93%.

If they are reporting 93% I would say you have a good case to get free warranty replacements from dji. Just copy the assistant page showing 80 cycles and 93% and I bet they want them back to study and send you two new ones immediately!

But to your question, as batts wear out, their internal resistance CAN increase substantially; means under load the voltage will droop like you say.
 
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Jbundy, unless you have dyslexia, I would certainly recommend you NOT fly EITHER of those batteries any more - both are VERY DEFECTIVE!

Know that % life is a simple mathematical equation: 100* (300-CYCLES)/300

So if both your batts have 80 or so cycles on them, their life is 73%, NOT 93%.

If they are reporting 93% I would say you have a good case to get free warranty replacements from dji. Just copy the assistant page showing 80 cycles and 93% and I bet they want them back to study and send you two new ones immediately!

But to your question, as batts wear out, their internal resistance CAN increase substantially; means under load the voltage will droop like you say.
I agree, I've had the same thoughts. I believe I will do as you say and contact DJI on this and see where it goes. Thanks for your input and I will definitely let you know what happens.
 
I for one would love to see screen shot of assistant showing the 80 cycles and 93%. Can you post please?
 
Will the dji go app capture sufficient information in case of crash or do I need to use litchi for example?

Sent from my SM-N920V using Tapatalk
 
I for one would love to see screen shot of assistant showing the 80 cycles and 93%. Can you post please?
Here's one

ImageUploadedByPhantomPilots - DJI Phantom Forum1450586785.087467.jpg


ImageUploadedByPhantomPilots - DJI Phantom Forum1450588939.885667.jpg


I have contacted DJI by email and they have opened a ticket. Will let you know what they say when they contact me.
 
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16v.. 4 cells... I thought your inspires were 22.2v with 6 cells? what is the NEW mah rating of the batteries shown here?

Also, what number of cycles do they advertise these for? It appears your batteries are not advertised for same 300 cycles max like our phantoms...

working backwards, assuming inspire life is same formula as phantom, it appears your batteries are rated for 1000 cycles! One calcs to 822 as rated charges, other 1200...

So again, either you batts are weird or the formula for inspires is different than phantom for life remaining... without more data to compare, I cannot say which.
 
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16v.. 4 cells... I thought your inspires were 22.2v with 6 cells? what is the NEW mah rating of the batteries shown here?

Also, what number of cycles do they advertise these for? It appears your batteries are not advertised for same 300 cycles max like our phantoms...

working backwards, assuming inspire life is same formula as phantom, it appears your batteries are rated for 1000 cycles! One calcs to 822 as rated charges, other 1200...

So again, either you batts are weird or the formula for inspires is different than phantom for life remaining... without more data to compare, I cannot say which.
I have a Phantom 3 Pro, the batteries are 15.2 volts and a 4480 mAh rating, as you say I believed that they are considered 300 cycle batteries. I did a little close flying yesterday and gaining altitude and flying forward with some wind resistance theses batteries fully charged are going a lot into the 3.5, 3.4 and 3.3 range which I know is not good. Hopefully DJI will give me some idea, until than I definitely do not want to fly on these batteries.
 
it would be interesting to see some 'good' battery screen shots to compare to.
Same here, I believe that I'm going to end up replacing them, the warranty is 6 months and less than 200 charges and I'm a few days over 6 months so probably won't qualify for warranty. I posted on the P3 forum here and no replies. I know I wasn't hitting theses voltages a month ago so maybe it just normal degrade? Wish I had payed more attention or the voltages when new, I definitely will the next time and record results.

I will let you know what DJI says when I hear something.

Thanks Yorlik, Safe flying!
 
When do you see 3.3v? during flight in some log file? Which one? Care to share it? If you do, I would go thru it and calculate your batteries internal resistance for reference (if possible). That could give you more ammunition to get replacements maybe... From what I have seen on various phantom cells, the internal resistance does not really change much over the life of the cells; means you should NOT be seeing 3.3v ever, unless you are flying down below 0% battery remaining, which I doubt you can do. You must have a 3rd or more batteries you are flying on now?
 
When do you see 3.3v? during flight in some log file? Which one? Care to share it? If you do, I would go thru it and calculate your batteries internal resistance for reference (if possible). That could give you more ammunition to get replacements maybe... From what I have seen on various phantom cells, the internal resistance does not really change much over the life of the cells; means you should NOT be seeing 3.3v ever, unless you are flying down below 0% battery remaining, which I doubt you can do. You must have a 3rd or more batteries you are flying on now?

I went out and did a quick flight and here is my log file. and added one quick one from last night
 

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