Hi,
I bought a new Phantom 4 Advanced anout 3 months ago. The battery that came with it had medium deviations in cell 4 from the first day.
Should I worry? Should I send it back?
I attach 9 screenshots from Airdata UAV site.

Just keep an eye on it ...  
BUT given its only 3 months since purchase - you could try for replacement from seller ...

For me ... I watch flight performance rather than such diagnostic apps ... reason being that they have no reference to batterys under load ...

If I find warnings appear during flight - or most likely - I see shorter flight times vs % battery - then I know its time to think about replacement.

Thanks for the tips!
The seller is a big retail store here in Greece and I don't think that they will respond fast. Maybe I should talk directly to DJI?
No warnings in DJI Go app so far but I don't use it a lot. I mainly use MapPilot for mapping missions.

If its an over-counter purchase - then a visit back to shop and to Customer Service ... they are obliged to take Warranty Claims ... last resort is DJi ...

Did you Credit Card Purchase ? Then you have the power of the CC company to assist you.

I don't think that they will understand anything about battery cell deviations...

GeorgeEV Posted at 11-1 03:57
I don't think that they will understand anything about battery cell deviations...

??

Until you confront them - how do you know that ? If the assistant fails to understand - ask for the Manager politely and put your case firmly. Calm, polite and firm explanation of the cell being in poor condition and would decline rapidly in use ... etc.

Should I worry? Should I send it back?
Probably not.
The only numbers I can see from the screenshots you posted (why 9?), indicate a difference of less than 0.1V.
Less that one tenth of a volt !!!   That's nothing.
Airdata gives a false idea of how serious tiny cell voltage differences are (and gives very little real data anyway.

If you really want to see what your batteries are doing, run a flight through the Phantonhelp log viewer and look at what the real data is telling you rather than Airdata's brief summary.

The screenshots correspond to 9 different flights and the deviation of cell 4 is in all of them. Between them I discharged the battery to about 8% and then fully recharge it to see if it helps but it didn't.
I have 2 more batteries that show almost 0 deviations in all cells.
This particular battery have this "problem". The difference of 0.05-0.06V is shown also in DJI GO in the battery screen.
I ask mainly because the battery is still under warranty and if I can ask DJI for a replacement.

As you found out - the deep discharge cycle to sort is a 'myth' and wasted effort.

'L' is right ... but its a decision you have to make ... if you don't feel comfortable with the battery - then request warranty replacement. Don't waste time here to be honest.... get in there and swap it.

GeorgeEV Posted at 11-1 04:45
The screenshots correspond to 9 different flights and the deviation of cell 4 is in all of them. Between them I discharged the battery to about 8% and then fully recharge it to see if it helps but it didn't.
I have 2 more batteries that show almost 0 deviations in all cells.
This particular battery have this "problem". The difference of 0.05-0.06V is shown also in DJI GO in the battery screen.

This particular battery have this "problem". The difference of 0.05-0.06V is shown also in DJI GO in the battery screen.
That's not a problem and is completely normal.
You are worrying about nothing.

+1

……………...

solentlife Posted at 11-1 04:04
??

Until you confront them - how do you know that ? If the assistant fails to understand - ask for the Manager politely and put your case firmly. Calm, polite and firm explanation of the cell being in poor condition and would decline rapidly in use ... etc.

Well said Solentlife  

Is the Battrie realy bad, the Go App will show a batterie warning.

Did you read the green banner on the bottom of your pictures?

My concern would be that that one cell is already showing difference. I agree its small - but its there while the other cells all show good. What is going to happen over time ? It is normal that a cell that is already showing difference will degrade faster than the others.

I am not one who likes some of these diagnostic apps - they can lead to paranoia if user is not experienced in determining its info. But they can be useful used correctly.

'L' is right that cells are rarely all same and odd ones will show deviation. The question is what does the particular user feel about it ? I get impression that OP is not happy with this deviation - therefore for peace of mind - it would be better to see about replacing the battery. That then solves the problem.

I have 3 P3 batterys and 4 boxes of various lipos to fly my more than 55 RC models. I can honestly say that not one of those batterys have same figures on all cells ... every battery will show a deviation across the cells. Do I do diagnostics on them ? No. Why not ? Because flight performance soon shows up a battery that is failing. It is rare actually for a LiPo to fail suddenly, it can happen but rare. The normal is for it to decline in power delivery.

Thanks all for the tips. I will keep the battery for now and see how it goes.

solentlife Posted at 11-3 00:14
My concern would be that that one cell is already showing difference. I agree its small - but its there while the other cells all show good. What is going to happen over time ? It is normal that a cell that is already showing difference will degrade faster than the others.

I am not one who likes some of these diagnostic apps - they can lead to paranoia if user is not experienced in determining its info. But they can be useful used correctly.

I highly doubt warranty would cover it though as its only minor, may do, but it may be within tolerance , so would need to bear in mind he could be footing the bill for a new one himself, or not....

Bashy Posted at 11-3 18:34
I highly doubt warranty would cover it though as its only minor, may do, but it may be within tolerance , so would need to bear in mind he could be footing the bill for a new one himself, or not....

Agreed ...

But I think my point of degradation possibility of that cell is possibility. If one of a set is showing greater deviation - whether it be tyres, bearings, cells ... it may indicate shorter life of that one.

Whatever - That battery would receive a red mark if it was mine and be used for less risk flights. I actually do have a P3 battery with a red mark - during a flight over the river - GO suddenly went to ZERO % ... AC never tried to land - it just carried on ... battery % came back and I flew home ...
It happened twice on that flight and scared the pants of me ! But its never happened again in later flights, but I still have it marked and use only for short distance / close in work.

Airdata overemphasises the significance of minor voltage differences.
But even Airdata say:  Note that even a perfect battery would have minor deviations and it is normal.

Airdata only offers a summary and doesn't show the actual data.
No-one who has been commenting here has looked at actual data to see what the real situation with this battery is.
It's really stretching things to make a determination based on just one number.

Labroides Posted at 11-4 02:52
Airdata overemphasises the significance of minor voltage differences.
But even Airdata say:  Note that even a perfect battery would have minor deviations and it is normal.

Agreed and is one of the reasons I don't use such apps'

I prefer the old ways ... if I fly and I find the battery going down quicker than normal ... if I have repeated shorter duration - I know that battery is on its path to never never land. I don't need an app to tell me !
If I really want to see any info ... even GO will tell me each cell voltage ... and I have various other 'tools' from my general RC that will give me actual numbers.