M2P battery overheating

[Polacheck]

I just had my thrid battery overheat with my Mavic Pro 2. The battery comes back from a flight smelling of burnt electrical and with a deformation spot (melted plastic) on the left rer lower side. DJI mave has been very good about these and has replace the first 2 covering all costs including postage each way and I assume they will do the same with this one. But I am quite baffled as to why this is occurring. The one two day occurred on my second flight but weather is cool and the drone has performed without any issues. Wondering if anyone else has experience similar problems. I am concerned that at some point, this might compromise the drone and it will malfunction or crash.

 

[Thomas B]

Welcome to the forum from the deserts of Arizona! Enjoy.

personally in I have had one M2P battery out of 10 show swelling. Each has well over 400 flights and recharges.

What is the production date on your batteries?

 

[Polacheck]

Mine have had far less hours (no more than 20-30). There has bee no signs of swelling even with the overheating ones. Just a burnt spot on the real and a smell of burnt electrics after the flight. The batteries preformed normally during flight. The first on refused to turn off after the flight but the other two turned of fine. In no cases. did the software indicate any problem. Do not find the production date but all my batteries have been purchased with in the last 6 months On the image you can see the deformed spot where the plastic has melted.

 

[DanMan32]

How does the battery cavity in the AC look, compared to battery? I'm thinking maybe it's the AC because it's strange one would do that let alone several.

Swelling yes, but not so much overheat.

 

[Polacheck]

No visible issues with the battery compartment within the aircraft. When the second one went I thought perhaps I got a bump pair of batteries from one batch/source. But with the third one, they have come from at least two different sources (I bought the extras in pairs from different sources).

 

[DanMan32]

I've taken apart one of those that had the most swelling. There's a circuit board against that back plastic going from the pins all the way to the top of the battery. Cells are behind the board so I doubt it's the cells.

Perhaps AC drawing too much current but not being detected?

 

[Polacheck]

Perhaps a short in the circuit board inside the battery? Perhaps caused by too much current being drawn by the AC? But as nothing detectable in the AC the source if not the cause is in the battery it appears

 

[DanMan32]

But that would be an interesting coincidence that more than one did the exact same thing.

 

[Polacheck]

I agree that there appears to be some problem beyond the batteries now that it has happened 3 times - but it is something intermittent. I have had numerous flights in between battery failures and including with the batteries that have failed. All a bit of mystery and a pain. See what DJI says when they get back from Christmas.

 

[Jet skier]

Welcome to the forum from the deserts of Arizona! Enjoy.

personally in I have had one M2P battery out of 10 show swelling. Each has well over 400 flights and recharges.

What is the production date on your batteries?

400 flights is amazing I don’t think I’ve ever had more than 80 flights on the battery before it swells and DJI has always replace them

 

[hiflyer201]

Send the drone and the batteries back to DJI...I'm pretty sure you'll end up with a new drone.

 

[DanMan32]

Any debris in the battery contacts on the AC?
There shouldn't likely be a short since the + is on one side and - on the other. But if sufficient pins aren't making contact, then the rest have to take up the extra load and could get hot.

 

[DMP (Dan)]

Resurrecting this thread. I have been flying the M2P since release, and had a number of batteries swell, but until today, I had never seen a battery overheat and start melting the plastic. 68 charge cycles prior to this flight. Manufactured Dec, 2019, and put into service July, 2020. Same heat location as the OP experienced - left rear. It smells like a cooked capacitor or resistor (I wasn't going to open it to look), and got so hot that the battery compartment on the AC deformed slightly as well.

The battery powered up the AC upon insertion rather than requiring me to power it up. Based on that alone, I decided to fly an easy test close to me so that damage would be limited if the battery failed. After a 7min, 20sec flight with a max height of 58' and a max speed of 15.68mph, I landed, and immediately smelled something burning. The battery appeared to power off, but the AC did not. I pulled the battery. The back end was too hot to touch, and was slightly deformed by heat. The base of the battery (where it would show signs of swelling if that had happened) was barely warm.

I then tested the AC with two other batteries. The first flight was gentle and close to me. The battery remained fairly cool. The second flight was 23,879' in total, with a max speed of 45.23mph. The battery was at 46% when I landed, and was warm, but not hot.

I'm fairly confident that with no history of battery issues on any of the five M2P AC I use, this battery is flawed.