Phantom 4 Advanced Battery Cracks

[rvrrat14]

On recent monthly detailed maintenance check I discovered a crack on the top of a P4A battery. The crack was on the top where the two thumb locks are. These are screwed on to the actual battery cell. The cracks are starting from the plastic injection mold dimples. Out of 4 batteries, all three are doing it, with one worse than others. These do not affect the fit into the battery compartment or the function of the battery itself. I contacted DJI and my batteries were our of warranty. I asked if I could buy just the tops and was told No, replace the batteries. Purely a manufacturing defect. A little superglue has stopped the spread and I will continue to monitor. Again, very small cracks not affecting the attachment to the drone or the battery cells themselves.

 

[MapMaker53]

If the superglue doesn't stop it, another common technique to keep a crack from spreading would be to remove the cap and drill a tiny hole at the very end of the crack.

 

[R.Perry]

Are you monitoring the cell voltage? If heat and expansion caused those cracks I would replace that battery. I know it isn't cheap, but with the P4 if that battery fails during flight you have a flying rock until it hits the ground and hopefully nothing else.

 

[rvrrat14]

Nothing noticed out of the ordinary with voltage readings. LIke I said, three batteries are doing it and they are all at the mold dimple. Batteries are not hot after flights.

 

[R.Perry]

I took my P4 batteries out and took a close look at them and I seen no signs of stress cracks. That is very interesting as to what might have caused those cracks.

 

[mdurbanek]

I have three batteries, and they all have a similar mold dimple.

• the mold dimples are at the bottom of the battery as it sits in the bird on each side.
• Battery "A" has cracks on both sides, extending upward approx 1/16 of an inch, and downward to the bottom of the lip of the cap.
• Battery "B" has no cracks on either side.
• Battery "C" has a crack on the port side, no crack on starboard.

The mold dimples on the intact cases are very similar in pattern. However on the the cracked cases, the dimples have changed: they are deeper and look melted.

Batteries are all about the same age, purchased last September. Cell voltage is 4.27 to 4.29 on all cells in all three batteries. "A" and "C" have been charged 14 times, "B" has been charged 18 times. Total flight time of my P4A is just a little over 10 hours.

I'd be awfully disappointed if these batteries fail or catch fire or worse, especially considering how much they cost. If there are any DJI employees lurking, it would be nice to know the company's position. I'll be asking them directly tomorrow. We'll see if they respond.

 

[R.Perry]

Personally with that few of hours DJI should replace those batteries, that's just my opinion. They do look like stress cracks to me, but you said they look melted, that means heat. The thing is all your cell voltages are good.
How low are you running the batteries before you land, and how hot to they feel?
When my batteries hit 30% I head for home because I know as cell voltage decreases amperage requirements goes up, and amps is what causes heat.

 

[rvrrat14]

The cracks are caused from manufacturing. They are all cracking at the same place; Mold dimples made during the manufacturing process. Simple.

No crashes. No cell damage. Voltage constant. No battery operation issues at this time.

DJI should at least offer replacement tops for these batteries.

Mine were purchased around Aug. of last year.

 

[R.Perry]

All I can say is I wish you the best of luck with them, and hopefully there won't be any issues.

 

[mdurbanek]

Personally with that few of hours DJI should replace those batteries, that's just my opinion. They do look like stress cracks to me, but you said they look melted, that means heat. The thing is all your cell voltages are good.
How low are you running the batteries before you land, and how hot to they feel?
When my batteries hit 30% I head for home because I know as cell voltage decreases amperage requirements goes up, and amps is what causes heat.

 

[mdurbanek]

I apologize R.Martin for not answering one of your queries. My controller is set to squawk when the charge reaches 20%, and to RTH at 10%. I have reached 10% a couple of times, but no more than that because I follow my rules.

 

[R.Perry]

I apologize R.Martin for not answering one of your queries. My controller is set to squawk when the charge reaches 20%, and to RTH at 10%. I have reached 10% a couple of times, but no more than that because I follow my rules.

You run your batteries lower than I do. I have a question, how hot is the battery when you run it below 20%?

 

[R Martin]

I apologize R.Martin for not answering one of your queries. My controller is set to squawk when the charge reaches 20%, and to RTH at 10%. I have reached 10% a couple of times, but no more than that because I follow my rules.

Ditto. I did convert to TB48s on the Inspire and added an additional 3-7 minutes of flight time per battery. (I only get 12-15 minutes from a TB47).