Swelling batteries

[WWK888]

So, I went back and counted, so far, assuming all complaints are true ( please note I am taking all at face value, even counting "I heard from a friend", " I posted on another forum" [ meaning I could of already counted them via the 1st phrase previously mentioned ] ) and I am not looking at user names for duplicates.

I am also not looking at manufacture dates even though the OP stated her had 2 made in 2019.... I also had to guess for people who said " all my batteries swelled " as there average seemed to be 3 I assumed 3.

So far 71.

Assuming a minimal batch of 10000 ( if you look at all the new/ refurbished drone sales, single batteries, and fly more kits, and an international company I would be willing to bet the amount purchased/ made at any given time to be far higher....) that means that 0.71% failed, let's be more generous and double it.... 1.42% failure rate does not seem to be a " bad batch".

More over almost all (I counted less then 10 that failed before warranty expired, and they were replaced by dji by their own words) outlived djis guaranteed life expectancy.

I am sorry if that makes people unhappy, but stop trying to organize a witch hunt. Your batteries failed, most after the guaranteed life expectancy, which isn't a set amount of flights, but a length of time. 6 months

Edit. Ment to add I went back and perused, every post. I perused not read every word, and for any I missed, I doubled the statistic...

I appreciate the effort you took to try and put some perspective on this issue but I do not think you have any way of knowing the actual failure rate based on perusing posts. Without an accurate number of actual batteries produced and a much larger pool of users you really cannot come to any realistic conclusion. I am sure there are many other owners out there that have had failures and are not even on this site.

As pointed out, the latest update appears to address the concern of failing batteries. I have never seen such a discussion about failed batteries from a particular production date on any other model. I only go back to the Phantom 3 so I may be wrong.

 

[Mega Man]

I appreciate the effort you took to try and put some perspective on this issue but I do not think you have any way of knowing the actual failure rate based on perusing posts. Without an accurate number of actual batteries produced and a much larger pool of users you really cannot come to any realistic conclusion. I am sure there are many other owners out there that have had failures and are not even on this site.

As pointed out, the latest update appears to address the concern of failing batteries. I have never seen such a discussion about failed batteries from a particular production date on any other model. I only go back to the Phantom 3 so I may be wrong.

Hmm.... where did I hear that from ( actual numbers...)

Much larger as defined by internet warriors, and not real, actual numbers. You can not state that as a fact, as you have ZERO clue how many batteries have been sold, how many have failed, nor how many have not, which is far more important of a ratio for comparison. You are going off of people who complain on the internet which as everyone knows, is the most factually easy to get any needed statistics..... sorry most (higher then 90 %) lipo failures are ebkac. ( Google if you don't know)

And yet this thread has been humorously feeding a " failed battery due to a bad batch " hysteria, which I am/ have been attempting to put into perspective.

 

[globetrotterdrone]

As summarised before, there are indications, that a batch in July/August 2018 seems to have a higher drop-out rate due to swelling, than others.
However it's hard to say, that there was a specific problem, as only DJI has all the figures to compare, especially how many batteries of that time still work fine.

Would be interesting to get an official statement, but I doubt we will ...

 

[Mega Man]

Allow me to interpret one very easily for you


" with few exceptions, all the batteries lasted till out of warranty. The few that didn't, were in fact warrantied and replaced, without cost to the user "

 

[WWK888]

I still find it strange my original batteries for my Phantom 3 Pro and my Phantom 4 are still operating perfectly after 3 years yet I have had three failures with my Mavic 2 Pro and Zoom within a year of purchase with less than 30 flights on each battery. I have properly charged and stored them all the same way.

 

[Mega Man]

It's been stated many times in this thread, different batteries, different chemistry, and the newer chemistry won't last as long.

 

[WWK888]

So is this a case of technology not improving? I m just asking, not arguing.

 

[Mega Man]

I have not gone to understand further on that aspect, but that's my understanding

 

[gnirtS]

A fairer test is compare to batteries from other drones and mavic 2s AFTER that. Its significantly higher in both fields.
Very very few if any people are reporting other batteries dying after 6 months use on any drone or any date.

It still looks like a bad batch or batches. There would have been *lots* made during that period.

The failure rate is significantly higher for mavic 2 batteries made in those 2 months than any other mavic 2 battery month or any other dji drone.

 

[paulatkin73]

may be i missed it, but, would not hurt to add - the last .510 firmware reduced the duration of an automatic battery self-discharge to 5 days from 10 days, that should be better for battery health. in the matching last GO4 app - currently only available on apple - you can now set that duration manually, i would suggest 2 days.
so, it would make sense to upgrade and set those parameters, if you forget to manually discharge batteries for storage.

 

[gnirtS]

Its available on android and apple.

If you do nothing, they defaut to 5 days now not 10.

 

[jason38]

I saw growing threads about swelling batteries and it starts to worry me a little...
Is that issue only known on Mavic 2 or is it a global issue?
To answer your question, I shoot videos mostly, so when I fly, the drone moves in the air, but rarely at top speed. I manage to make it smooth, even if I need to accelerate video on mounting....
BTW, I sometimes discharge a battery that is fully loaded, and which didn't fly since a while ,like a week or two, when conditions for flying are not as nice as expected.
To do that, I just take off and hover at about 10ft ,time for the battery to discharge until 25-20%. When I land, the battery is never hot...even the drone is not hot, and the cooling fan isn't working (after 20-25min hovering)... I did that this summer one time, it was nearly 35°, no wind, hovering above concrete....
To store batteries, I just charge them up to 50-60% and store them in a tempered room. When I want to fly, I charge them to 100%, then fly within the week, and do it again...(like most people tell to do on most threads about batteries)
I never had any trouble from any of my 3 batteries since more than a year with the same batteries...

I am wondering, all other things being equal, if the type of drone use is also a factor in the battery swelling issue. I shoot almost exclusively video at 30mph, which provides additional cooling during flight. @gnirtS stated he shoots mostly photos, which would imply more hovering than flying. Hovering would likely build up more heat than continuous flight, especially in a high ambient temperature to begin with. I haven't seen any swelling yet on 6 M2 batteries from December on, and my batteries are also not excessively hot upon landing, even though I land between 0 and 10% remaining on every flight. Anyone else with swelling issues predominantly shooting stills in a hover rather than continuous video at 30mph? Thoughts?

 

[gnirtS]

It seems almost entirely to do with manufacture date of the batteries as opposed to charging, discharge,storage or temperature.

 

[DanMan32]

The change in allowing setting days to discharge and defaulting to 5 days seems more like a pacifier rather than admitting DJI has a bad series of batteries instead of offering replacement if swollen, low cycles, and made during those two months. Latter may be costly to DJI, but would make for much happier and loyal customers.

 

[Mega Man]

Or, maybe.... just maybe they are making it so you can change discharge time.... like most if not all of their other drones....


... just maybe....

 

[DanMan32]

Yes, but consider the timing for the change and the change in default setting.
Default had been 10 days for years. All of a sudden it's 5 days, just after a rash of swollen batteries, despite the fact that the majority of the swollen batteries were produced between 7/2018 and 8/2018.

I understand Toyota did the same thing with oil change interval. They had a problem with one of their cars pooling oil in a spot causing premature sludge. So Toyota changed interval to 5K across their fleet even though most of their vehicles could easily handle 10K. Honda designates 10K oil change interval.

 

[Jkagapo]

Mine too is swelling, i had two of them, but i still used i just a zip tie around the battery to make sure they will not pop out while flying up in the air. Do you think its a good idea too fly with swelling bat. For M2?

 

[DanMan32]

Depends on how bad the swelling. Even on my worst one where one latch unlatches during flight, I've successfully flown it under controlled circumstances: close by and very low altitude.

I've just tested if there's any loss of capacity. Compared to new ones I bought last month, new ones hover for about 23 minutes, the two swollen ones hover for about 21 minutes.

If you're not comfortable flying with it, you can always use it for ground work such as firmware updates, extracting video/photos from internal storage, checking settings, and even preflight warm up that sometimes can take a minute or two.

What is the production date of your swollen one?

 

[Liquidstone]

My first post.... just sharing my battery swelling problems with my M2P. I bought the M2P and FMC kit last April 20, 2019. The batteries are supposed to have a warranty of 6 months or 200 charge cycles. I contacted DJI Philippines and they referred me to the dealers from which I bought the items. Warranty deadline is October 20th, and I'm 300 km away from the capital where the dealers are. I don't think I can physically make it to the dealer before October 20th, but I hope they'll honor the warranty if I can email the details and photos before that date.

FWIW, out of my 3 batteries, 2 have swelled bad enough that I have difficulty locking them in place, and I won't dare to fly with these anymore, as they might detach in mid-air. One unuseable battery came with the M2P, while the other is from the FMC kit. The third battery has less swelling and still easily locks in place (this is the second battery of the FMC).

Screenshots of battery info - all were manufactured 2018-11, with charge cycles of 15, 21 and 22, respectively.

And photos of the swelled batteries (first 2 are unuseable, last has least swelling):

I hope the dealers will honor the warranty.

 

[DanMan32]

DJI themselves should honor the warranty just as they would for an AC warranty issue.

I can see two legitimate reasons to suggest going to a dealer though:
A. Possibly faster replacement, particularly if the dealer is local
B. The concern of shipping a bad LiPo battery