This is my 3rd in line for usage battery, ie, does not always get used, I did today however and as I always inspect them after use I noticed this, as seen in the image, its only had 17 charges, surely an £180 product should not do this, granted, its probably over a year old now, but that's beside de the point when many go over the 200 charge mark, I take it I have no come back at all with this? Overheating or shorting perhaps?

How many times fully charged? and what is with the 4rth pin from the right side??

Peterx Posted at 6-30 08:37
How many times fully charged? and what is with the 4rth pin from the right side??

It says 17 times in the image and the pin is what I'm on about, it's melted some, not just that one either, click the image, then click the thumbnail to view the full size image and you will see... Pin 1,3,4 and 5 too

Heat builds up from not making a good contact. The heat is only at that point of contact. There is a problem for sure, but it is not the battery cells getting too hot.

It's only this battery, I have 3 others and all were used today :/

What state are the corresponding mating pins in?

Goldenseal Posted at 6-30 09:27
Heat builds up from not making a good contact. The heat is only at that point of contact. There is a problem for sure, but it is not the battery cells getting too hot.

I agree.  The cell devastaion is too small for a short cut.

Sean-newbie Posted at 6-30 11:23
What state are the corresponding mating pins in?

Theyre fine, twas the first thing in checked

Goldenseal Posted at 6-30 09:27
Heat builds up from not making a good contact. The heat is only at that point of contact. There is a problem for sure, but it is not the battery cells getting too hot.

So what would cause poor contact? We can deffo rule out battery insertion issue, ie not inserted fully, this is one of my pre-flight  checks, with that and the props, i check multiple times (at least 3) before power up, i always wiggle the battery whilst giving a little tug, there is never any pull.

And the inevitable question is, can it still be used?

Bashy Posted at 6-30 19:07
And the inevitable question is, can it still be used?

I notice one of the cells showing only 4.18v (down on other cells)...If you don't use these batteries regularly they can give you grief.

PowerBand1 Posted at 7-1 13:36
I notice one of the cells showing only 4.18v (down on other cells)...If you don't use these batteries regularly they can give you grief.

Its only out by 0.01V and its 4.27v as opposed to 4.28v

Bashy Posted at 6-30 19:06
So what would cause poor contact? We can deffo rule out battery insertion issue, ie not inserted fully, this is one of my pre-flight  checks, with that and the props, i check multiple times (at least 3) before power up, i always wiggle the battery whilst giving a little tug, there is never any pull.

I really don't know ? Anything electrical that doesn't make good contact will burn the contact points. Ask an electrician.  

Bashy, the power is drained thru multiple pins in parallel for redundancy ... If one connector gave up for whatever reason, the others will have to take over and may get really hot if you fly full throttle sport mode for several minutes. Whatever, personally I would not play with the devil ...

This is why you should only use the genuine DJI chargers.

AntDX316 Posted at 7-1 22:52
This is why you should only use the genuine DJI chargers.

BULLSH*T ALERT

It has NOTHING to do with what charger you use. It happens when the battery is in the aircraft, not the charger. Shut up!

Geebax Posted at 7-1 23:05
BULLSH*T ALERT

It has NOTHING to do with what charger you use. It happens when the battery is in the aircraft, not the charger. Shut up!

How come I don't have this problem?

Geebax Posted at 7-1 23:05
BULLSH*T ALERT

It has NOTHING to do with what charger you use. It happens when the battery is in the aircraft, not the charger. Shut up!

This time I will join the choir of angry members of this noble forum ... Ant, seriously, I don't know what's wrong with you and why you're expressing absurd, misleading opinions ... But please, stop doing this ...

AntDX316 Posted at 7-1 23:10
How come I don't have this problem?

I inadvertently clicked on 'upvote' there (should've been reply).

The reason you are not seeing this along with many thousands of others is because your battery doesn't have a high resistance contact that overheats when too much current is drawn through it.

If the charger were faulty it would affect all the batteries in the same way, especially so as this battery seems a lot less used than the others.

Bashy Posted at 6-30 19:06
So what would cause poor contact? We can deffo rule out battery insertion issue, ie not inserted fully, this is one of my pre-flight  checks, with that and the props, i check multiple times (at least 3) before power up, i always wiggle the battery whilst giving a little tug, there is never any pull.

It could be a number of things from contact pressures against each other, corrosion on battery contacts (this isn't the one that took the dunk is it ?) to dry solder joints on the other side, to one moment in time where there was a huge demand on this particular battery. Or a combination of these.

Whether it could be used again to fly is your choice I suppose, but risk of failing is probably a lot higher than it would be, or perhaps it could lead to aircraft contacts being damaged.

Aardvark Posted at 7-2 00:27
It could be a number of things from contact pressures against each other, corrosion on battery contacts (this isn't the one that took the dunk is it ?) to dry solder joints on the other side, to one moment in time where there was a huge demand on this particular battery. Or a combination of these.

Whether it could be used again to fly is your choice I suppose, but risk of failing is probably a lot higher than it would be, or perhaps it could lead to aircraft contacts being damaged.

It is interesting that the problem only occurs with P4 batteries, after DJI changed the connector type from the very reliable spade connector used in the P3 aircraft and batteries. It is also worth noting that spade connectors are extremely common in automotive applcations, where the common factor of low voltage and high current occurs.

Aardvark Posted at 7-2 00:11
I inadvertently clicked on 'upvote' there (should've been reply).

The reason you are not seeing this along with many thousands of others is because your battery doesn't have a high resistance contact that overheats when too much current is drawn through it.

Nah, deep down you know I'm right.
At Captain level, you know where everything is w/o really looking at it.

AntDX316 Posted at 7-2 02:57
Nah, deep down you know I'm right.
At Captain level, you know where everything is w/o really looking at it.

AntDX316, shut up and leave us alone!!!

Matthew Dobrski Posted at 7-2 07:15
AntDX316, shut up and leave us alone!!!

You've never posted until now.  I wonder how many people feel the same way.  How does this happen all the time? The "God system" at work all the time whether we know it or not and like it or not, of course.

AntDX316 Posted at 7-2 13:19
You've never posted until now.  I wonder how many people feel the same way.  How does this happen all the time? The "God system" at work all the time whether we know it or not and like it or not, of course.

"I wonder how many people feel the same way.  How does this happen all the time?"

And the lowest common denominator is ???? (for those who did fractions :-)   )

Geebax Posted at 7-2 00:47
It is interesting that the problem only occurs with P4 batteries, after DJI changed the connector type from the very reliable spade connector used in the P3 aircraft and batteries. It is also worth noting that spade connectors are extremely common in automotive applcations, where the common factor of low voltage and high current occurs.

Very true, I suspect it's just poor contact between the connectors, if I remember correctly the P3 terminals were much larger.

Matthew Dobrski Posted at 7-2 07:15
AntDX316, shut up and leave us alone!!!

In British terminology he's a 'wind-up merchant'

https://en.wiktionary.org/wiki/wind-up_merchant

Aardvark Posted at 7-2 15:08
Very true, I suspect it's just poor contact between the connectors, if I remember correctly the P3 terminals were much larger.

Yes, with considerably more contact area.

Wow, this soon escalated, just to put heed on your idea Ant, i do not possess any other type of charger, just the original that came with the P4P, well, it looks original, good fake if its not ;)

No, not that one that dunked, that one died, it would never take a charge since, i even tried to charge it the other day in case it sorted it self out, i would have swapped ctrl boards with this one. I keep it sat in a draw, totally dead lol reluctant to throwing it out, saying that, i have a summer house full of stuff im reluctant to throw out

The main contact that melted, the connected inside is actually tighter. I have cleaned up the melt so i can see all the connections.
Yesterday, i powered on the AC with said battery and set it to hover in the garden, no new melt, no issues.

Just to set the picture, bear in mind most of my days are mess about but many are under 20mph gusts
It was a breezy day, edging towards 30mph gusts at 10m, probably was a little more higher up, it was a just mess about day.
A few speed trials here and there but no distance, i think it was about 6000 ft at most, speed got up to 60 or 62mph.
No warnings re over speed BUT, i did get some compass errors show up, as did my mates Mavic Pro, she said entering ATTI but she never did.
We take off where we always do, about 15ft from the car on a dirt track (farmers field track) , flown there many, many times, its my go to spot, nearest inhabited property is at least 2 miles away, nearest power line is about 200m away.

I will give this one a separate line as it may have a bearing on this, i was zipping along in sports mode at about 100ft height, i then, centered the forward stick and turned the drone round 180º to face me and hit down stick to 100%, i was coming hot as you would say ;) Now, what i am about to say next, i didnt think it was possible with the later DJI products as they are limited, but it did it none the less, we both saw it, it did that bad wobble (VRS perhaps?), the whole craft, not just the gimbal, it lasted only for a few seconds (i think i  let go of the sticks) but enough for it to do wobble about 4-5 times, my only explanation was that there could have been enough of a down draught from the wind to cause unstable air  that in-turn caused the issue, i was recording at the time, but you couldnt tell that it happened, thats how good the gimbals are in these P4P's i binned it and formatted the card for next time, dont get me wrong, its always had a little wobble when descending, this was a worry it might flip wobble, it had to have been right on the limits of the gimbal.
Had the gimbal been of poor quality, this is what it would have looked like (goto 1:35)

I tested the battery yesterday, the battery went up to 50ºC with 2.5 lights left, once it reached the 50ºC i brought it down, and checked the battery, the connector was VERY hot, i mean that hot my lip test failed, it would have burnt had i let it touch longer then a split second, also would have burnt my finger had i left it on longer than a few seconds. I then tested with another battery, at the 2.5 flash mark, the battery hit 47ºC, i brought it down and checked the connector and it was fine, it was only luke warm.

So,  i proceeded to molest the connector, i used a stanley blade and closed the connections as best i could, in the process i broke one of the dividers, and glued it back in and then tested it again, i let it get back up to the 50ºC  and brought it down again, battery was nearly dead anyway at this point, i did the lip test again and it was just like the other battery, luke warm  to the touch.

My theory, perhaps that serious wobble shook it up enough to widen some of the terminals in the connector thus resulting in the issue at hand?

PS, test was done at ground level in my garden, (yeah, thats right CAA, in my garden :p ), well, at about 2-3ft, over thick short grass, i was taking no chances there lol

So, i do have a spare connector on my dead battery, but sadly i may as well solder using a banana  as with the real thing, ends up in a similar mess