Greetings all,

Yesterday while flying at about 100 feet in sport mode, my P4P had a sudden and total loss of power.  The aircraft was about 600' away when my screen froze and the Phantom fell to the ground destroying the camera and damaging the shell.  Flight logs revealed nothing abnormal.  They just abruptly end.  Close examination revealed small areas of melted plastic on the connector on the battery.  See the attached image.  Apparently it is possible for the battery contacts to just barely be making connection and when you use a lot of current, like in sport mode, they can heat up to the point of eventually causing total power failure and impending crash.

I have sent my P4P to DJI for repair along with the battery which caused the crash.  In a fair scenario, I think DJI should replace the battery for free and at least pay for some of the repair since it WAS NOT PILOT ERROR, but I doubt that's what will happen.  So maybe you want to check your batteries periodically for signs of the connector overheating.  I will make this part of my preflight routine from now on.

--Jim
(Burbank, CA)

P.S.; Here is a link to the flight log https://www.phantomhelp.com/LogViewer/P6HWM0PHLIBLLP986FY0/

They should replace the whole works.  That's a design flaw.  Poor contact causes increased resistance in turn generating heat. It would be interesting to know how much current that guy is pulling when the system is at full tilt.

Hi, we're sorry to know about this situation. Our team will provide an appropriate resolution once we've done with the evaluation in your unit. The items that we need to repair or replace will be covered depending on the outcome of the investigation and if the unit is within the warranty coverage. You may check the warranty period of our products using the link below. Please let us know if you have other concerns. Thank you for continued support.
https://www.dji.com/service/policy

Anokadrone Posted at 4-8 11:43
They should replace the whole works.  That's a design flaw.  Poor contact causes increased resistance in turn generating heat. It would be interesting to know how much current that guy is pulling when the system is at full tilt.

Interesting you should ask.  According to the flight records the aircraft was consuming current in the range of 19.9A to 26.3A at the time of the power failure.  This is at approximately 15 volts.  That works out to  between about 300 to 400 watts power consumption which is typical in sport mode.

--Jim
(Burbank, CA)

The $64000 question..........still under warranty?

ALABAMA Posted at 4-8 14:30
The $64000 question..........still under warranty?

thats a good question?

Jim Watkins Posted at 4-8 14:02
Interesting you should ask.  According to the flight records the aircraft was consuming current in the range of 19.9A to 26.3A at the time of the power failure.  This is at approximately 15 volts.  That works out to  between about 300 to 400 watts power consumption which is typical in sport mode.

--Jim

That is also consistent with hard braking, which was also indicated. But in any event, I believe the power connector system used on the P4 series aircraft is a technically poor solution. Overheating of the contacts has been reported many times on this forum, as have instances where the aircraft suddenly lost power and fell. The previous P3 aircraft used much more suitable spade connectors for the power and, as far as I can remember, never exhibited the power loss scenarios of the P4 aircraft. In my opinion, DJI should foot the bill for the entire repair, as the battery connector is a point of failure designed into the aircraft.

BagoDJIoperator84 Posted at 4-8 14:33
thats a good question?

It is not under warranty.

Geebax Posted at 4-8 15:14
That is also consistent with hard braking, which was also indicated. But in any event, I believe the power connector system used on the P4 series aircraft is a technically poor solution. Overheating of the contacts has been reported many times on this forum, as have instances where the aircraft suddenly lost power and fell. The previous P3 aircraft used much more suitable spade connectors for the power and, as far as I can remember, never exhibited the power loss scenarios of the P4 aircraft. In my opinion, DJI should foot the bill for the entire repair, as the battery connector is a point of failure designed into the aircraft.

Yes.  I owned a P3P, my first DJI product.  It DID have a much more robust battery connector.

Wouldnt a battery that has not been fitted 100% in place, i.e. only one latch or neither,  also cause this to happen? If its not 100% in place then it will not have a decent connection thus producing said arcing etc....

Bashy Posted at 4-8 18:59
Wouldnt a battery that has not been fitted 100% in place, i.e. only one latch or neither,  also cause this to happen? If its not 100% in place then it will not have a decent connection thus producing said arcing etc....

I guess that is also a possibility, but if the connector system is poorly designed, then it is also more likely to be an issue. My point is that this problem only began to surface in the P4 series when they changed to the larger connector.

Hi Jim, I’m very Sorry to read about this, unfortunately.

Wish there was something I could do, to help you with, in having it replaced...

Where does that leave you now?


RedHotPoker

Bashy Posted at 4-8 18:59
Wouldnt a battery that has not been fitted 100% in place, i.e. only one latch or neither,  also cause this to happen? If its not 100% in place then it will not have a decent connection thus producing said arcing etc....

Good point Bashy.  Dead right !

Jim Watkins Posted at 4-8 14:02
Interesting you should ask.  According to the flight records the aircraft was consuming current in the range of 19.9A to 26.3A at the time of the power failure.  This is at approximately 15 volts.  That works out to  between about 300 to 400 watts power consumption which is typical in sport mode.

--Jim

Wow !  That's  a shipload of power out of a little battery pack !

That is a lot of power to put through that tiny connector.  That's why that battery really gets cooking when you're doing aerobatics.  (not that I would do such a thing)  It gets cooking just flying normally.

RedHotPoker Posted at 4-8 22:26
Hi Jim, I’m very Sorry to read about this, unfortunately.

Wish there was something I could do, to help you with, in having it replaced...

I still own my old P4 and the P4P is at DJI for repair.  I like my P4P and I do not want a Mavic.  If the P4P were still in production, I would buy a refurbished one but they are hard to find now so I am getting my old P4P repaired.  So, lets see.  The camera will need to be replaced ($700.00), The shell will need to be replaced (65.00) and of course there's labor ($150.00).  THat totals $915.00 and don't forget shipping to return it to me.  So fixing it will cost about the same as a refurbished P4P if they were still available.  DJI should pay for this AND give me a new battery to replace the one that caused the crash.  Why?  Because their design flaw is what caused the crash.  Someday, some company with better customer relations will sell drones that are competitive with DJI and when they do, I'm done with DJI.  They have no respect for their customers.

--Jim
(Burbank, CA)

Don't be harsh on them till you know the outcome.   I'd say you have a 50/50 chance. I've seen them refuse , because out of warranty,  replace completely and possibly give a discount on another.  

Jim Watkins Posted at 4-9 11:05
I still own my old P4 and the P4P is at DJI for repair.  I like my P4P and I do not want a Mavic.  If the P4P were still in production, I would buy a refurbished one but they are hard to find now so I am getting my old P4P repaired.  So, lets see.  The camera will need to be replaced ($700.00), The shell will need to be replaced (65.00) and of course there's labor ($150.00).  THat totals $915.00 and don't forget shipping to return it to me.  So fixing it will cost about the same as a refurbished P4P if they were still available.  DJI should pay for this AND give me a new battery to replace the one that caused the crash.  Why?  Because their design flaw is what caused the crash.  Someday, some company with better customer relations will sell drones that are competitive with DJI and when they do, I'm done with DJI.  They have no respect for their customers.

--Jim

Hi Jim

I am interested in the history of the battery because I don't buy the "poor connection" and "too much power draft" arguments, this would make these types of accidents much more recurrent.

I mean basically cycles of the battery, whether it was charged well within 24 hours before flying or it was a battery that somewhat had started autodischarge, have you ever charged it still hot, etc.

I think DJI is at fault here just because they don't make public statements about common failure modes of their products but I hope regulators make DJI to spit out the truth in the future.

Jim Watkins Posted at 4-9 11:05
I still own my old P4 and the P4P is at DJI for repair.  I like my P4P and I do not want a Mavic.  If the P4P were still in production, I would buy a refurbished one but they are hard to find now so I am getting my old P4P repaired.  So, lets see.  The camera will need to be replaced ($700.00), The shell will need to be replaced (65.00) and of course there's labor ($150.00).  THat totals $915.00 and don't forget shipping to return it to me.  So fixing it will cost about the same as a refurbished P4P if they were still available.  DJI should pay for this AND give me a new battery to replace the one that caused the crash.  Why?  Because their design flaw is what caused the crash.  Someday, some company with better customer relations will sell drones that are competitive with DJI and when they do, I'm done with DJI.  They have no respect for their customers.

--Jim

This whole thing stinks.,

I feel, Yes DJI should replace the whole unit, a new battery included.

Good luck. Let us know how it pans out. Thanks.

RedHotPoker

Jim Watkins Posted at 4-8 17:58
It is not under warranty.

yea, i looked like poor battery connection and heated up.

UPDATE,

I am pleased to report that although DJI initially was going to charge me $500.00 plus tax for this repair, they eventually decided to pay for the entire cost of repairing my P4P as well as providing a replacement battery at no charge since the crash was caused by the failure of the battery connector and not operator error.  Thank you for being fair DJI.  I am satisfied with the outcome, however, going forward, I will be checking the battery connector everytime as part of my preflight routine.  You probably shouold too.  

Jim
(Burbank, CA)

OEM battery? There are a TON of reports around. I bought two and they worked great for a while then one day it fell like a rock. Then noticed that both of them were slightly melted. I have been through at least 24 OEMs over the last couple of years and have not seen even a hint of it. Averaging close to 500 flights a year so they have all definitely been tested.

CHASCOADMIN Posted at 4-17 15:55
OEM battery? There are a TON of reports around. I bought two and they worked great for a while then one day it fell like a rock. Then noticed that both of them were slightly melted. I have been through at least 24 OEMs over the last couple of years and have not seen even a hint of it. Averaging close to 500 flights a year so they have all definitely been tested.

It was an OEM  battery.  I have 6 of them.  I am not sure I understand your comment.  Obviously, you do a lot of flying.  In your experience, is this a fairly common problem or is it pretty rare?  I am REALLY HOPING this doesn't happen again.

--Jim
(Burbank, CA)

Glad it was settled to your satisfaction.

Glad DJI took care of you on this one.  I think its one of those things that happen when you push a machine to its operational limits.  Systems get stressed and design margins get shaved to little or nothing.  Murphy's law is always at the waiting if you present the opportunity.  

Jim Watkins Posted at 4-17 14:11
UPDATE,

I am pleased to report that although DJI initially was going to charge me $500.00 plus tax for this repair, they eventually decided to pay for the entire cost of repairing my P4P as well as providing a replacement battery at no charge since the crash was caused by the failure of the battery connector and not operator error.  Thank you for being fair DJI.  I am satisfied with the outcome, however, going forward, I will be checking the battery connector everytime as part of my preflight routine.  You probably shouold too.  

WOW that great DJI stepped up to the plate..See sometimes it works.

I've lost 2 P4As due to battery connection melt. People suggest the battery might not have been installed securely. Funny thing is both batteries were fused in as tightly as installation could have allowed on recovery. Yes, those big beaver teeth connections on the P3 Is a far better way to handle in/out friction they go through. I'd like to micrometer new vs old P4A connection pins for wear comparison.
My current P4A has a good snug fitting battery bay, unlike the last 2. They were loose fitting. I don't know why this is.
I now scan my battery post flight with a $40 handheld IR thermometer at the connection and battery body points. If the connection temp is hotter than the battery body, there's trouble. I urge all P4 pilots to do the same scan after every flight - for public safety.

The first 1 I lost cost me refresh replacement. The second 1DJI charged me for repair because it was just out of warranty. Even after appeal. It would be nice if we all got fair treatment FROM DJI.

Jim Watkins Posted at 4-8 17:58
It is not under warranty.

Hi Jim my name is Wayne I live in the UK and someone on the forum pointed me this way i have had my phantom p4p drop from the sky just like yours on the 5 may can you give me any advise i am sending it in for repair but it is the same in every way to yours burnt battery

Wizzokartworld Posted at 5-8 02:21
Hi Jim my name is Wayne I live in the UK and someone on the forum pointed me this way i have had my phantom p4p drop from the sky just like yours on the 5 may can you give me any advise i am sending it in for repair but it is the same in every way to yours burnt battery

Take photos of the connectors on the battery if there is evidence of heating, charing or melting and send them along with detailed explanation of the incident to DJI.


Good luck,

--Jim

Jim,
I just had the second P4 pro fell out the sky (yesterday and two months ago). The batteries were overheated (expansion) but the connections don't show any charring or melting. I don't know if I would buy another P4 if they are falling out of the sky.  
Thanks for the information.
Hal

Glad to hear of the positive outcome for the OP on this particular issue.

Jim Watkins Posted at 2019-4-17 14:11
UPDATE,

I am pleased to report that although DJI initially was going to charge me $500.00 plus tax for this repair, they eventually decided to pay for the entire cost of repairing my P4P as well as providing a replacement battery at no charge since the crash was caused by the failure of the battery connector and not operator error.  Thank you for being fair DJI.  I am satisfied with the outcome, however, going forward, I will be checking the battery connector everytime as part of my preflight routine.  You probably shouold too.  

this is a good outcome!