Swelling Battery caused Crash

[gnirtS]

I know a lot of people with mavic 1s. Most are unaware you could change it, i dont know anyone that did (including me).
Its a feature that the majority of users (who dont use internet forums and just fly around) are unaware exists or see the point in using.

 

[GadgetGuy]

I dont think heat alone.
I think its a chemistry defect whose effects *may* be accelerated with higher ambient temperatures. But the defect still exists in those batches regardless but is slower to manifest.
To me this seems to be a specific failure mode - its small cycle batteries (ive seen 15 - 40 mentioned a lot) which is (i) significantly under the quoted endurance and (ii) seems remarkably consistent). It also seems to be the case that electrically the battery appears fine in terms of voltages, current drain, deviations etc.

To be honest 150 or so cycles id kind of expect some swelling due to normal wear and tear. Thats about the level my mavic 1 batteries started suffering.

Exactly, and it was only very mild swelling, and he also spent those 150 cycles in extreme heat. Normal wear and tear!

 

[GadgetGuy]

Based upon the data we have collected so far, DJI fixed the swelling problem in all M2 batteries manufactured after 2018.08. It is not an issue in batteries manufactured since then, so there is no design defect that needs changing. It was two bad batches of batteries: 2018.07 and 2018.08.

 

[El Dedos]

I was flying my Mavic pro platinum over water and was returning to home and got about 3 foot over the land ( thank God ) and my battery just popped off… I noticed that the battery had swelled up but I didn’t think about

I've been fighting DJI for a month now on 2 of the batteries I got in the "bundle" of my Mavic Zoom. They were bulging and I was afraid they would pop off.
I had DJI Care refresh and they wanted the drone sent in. Not going to send a perfectly good drone when
all that needs done is replacing the batteries. I will give them that they won't replace both (sucks) but they are trying to charge me for 2 batteries. Hey the Care refresh says "batteries are covered" . I finally told them I would pay the $119 for one battery as the replacement "fee" and still no answer. What good was the Care refresh if they aren't going to stand behind it. I own a hell of a lot of DJI equipment. Practically everything they make but if I
don't get treated right on this I'm done with them.
My P4P/Mavic Pro/Spark /Mavic Air etc don't have "bulging" batteries. So I think they had a bad run.
S. Lewis

 

[Greenflash]

Here is my recent talk with DJI about the bad batteries. Spent over $400. USD to replace the 3 swollen batteries. They did apologize which I excepted.

 

[gnirtS]

Yeah i had similar. Its likely DJI (or at least support) are totally unaware of any possible problem.
I had no joy out of them at all.

 

[Billyboy72]

I was flying my Mavic pro platinum over water and was returning to home and got about 3 foot over the land ( thank God ) and my battery just popped off… I noticed that the battery had swelled up but I didn’t think about taking a picture of it at the time but I wrote DJI and supplied them with my flight records and everything else they asked for and they wanted me to return my Mavic to them for analysis… I tried to explain it’s not a problem with my Mavic it’s a problem with their swelling batteries but they still wanted me to return the Mavic for to them for analysis and I refused, because they couldn’t tell me if it was going to cost anything or not, so I wasn’t about to return my Mavic to them and then end up with a $300 bill for servicing, when I know after reading these posts that I’m not the only one that’s had this problem! In my opinion they should offer free insurance and rebuild the batteries correctly to where they will not swell… I’m really pissed… Now I’m scared to fly over water !

Out of 3 I only have one that hasn’t yet swelled up and that’s my number one fear it swelling and popping out while in the air. I agree these batteries should NOT be swelling after such a short time having them. All the money we pay for the fly more packages just to get stuck with one out of 3 batteries until that one decides to go.

 

[BerndM]

I use a strap around the body/battery to make sure the battery never pops off

 

[modbuilder]

I can tell that there aren't many RC pilots in here who've spent much time with electric flight. There are several absolutes for LiPo batteries that are worth attending. Debate them all you want, but do the things below and you enjoy lots of flights with your batteries. Has nothing to do with DJI. Has to do with LiPo, and all the other Lithium-based batteries.

- Don't store them at 100% charge. Recharge them when you need them. Store them as close to 50% as you can manage. DJI doesn't give you a way to do this easily. Try to catch a recharge near 50% and stop if not going to use it very soon.
- Don't recharge them while warm, and especially not if they're hot to the touch.
- Carry a cooler with a cold pack that doesn't sweat for cooling down warm batteries prior to recharge if you're in a hurry.
- Understand that a swollen LiPo means that the chemistry has been damaged irreversibly. The capacity is reduced, and it will deteriorate faster in the future.
- Know that a swollen DJI battery is trying to pop out of it's click-in fastening. This is in system that is exposed to g-forces that are trying to remove it anyway. If it's swollen, just don't fly it.
- Regarding LiPo fires -- The chemistry is much like a road flare. It is indeed very hard to extinguish, and it's very hot and volatile.

 

[gnirtS]

Yes. People are well aware of all the above. Its been discussed many many times.
But these batteries are swelling prematurely after being properly looked after.

The "absolute" dont apply here.

 

[otisbrazwell]

id say the smart person would not fly with a bulging battery. do the right thing chuck it and dont fly until you get a new one. with all the talk about not flying out of line of sight but a pilot would knowingly fly with a failing battery. its like flying a plane with a motor thats failing

 

[bktodd80]

It may be worth it to replace your charger as well.

Common causes of battery swelling include:

1. Overcharge conditions which accelerate parasitic reactions between the electrodes and electrolyte, with release of heat and gases.
2. Poor cell quality and design with low anode to cathode stoichiometric ratios, particulate contamination
3. Mechanical damage to electrodes induced either during cell assembly or from the product application
4. Excessive temperatures (Do not leave your cell phone inside your car)
5. Deep discharge of cells

reference: Why Do Lithium-Ion Batteries Swell?

 

[gnirtS]

Again that doesn't explain why only batteries produced in July and August are swelling and ones after that on the same chargers are fine.

 

[GadgetGuy]

It may be worth it to replace your charger as well.
Common causes of battery swelling include:

1. Overcharge conditions which accelerate parasitic reactions between the electrodes and electrolyte, with release of heat and gases.
2. Poor cell quality and design with low anode to cathode stoichiometric ratios, particulate contamination
3. Mechanical damage to electrodes induced either during cell assembly or from the product application
4. Excessive temperatures (Do not leave your cell phone inside your car)
5. Deep discharge of cells
   reference: Why Do Lithium-Ion Batteries Swell?

Your #2 is the most likely cause, given that it has been isolated to battery Production Dates of 2018.08 and 2018.07.

• Poor cell quality and design with low anode to cathode stoichiometric ratios, particulate contamination

 

[WithTheBirds]

It may be worth it to replace your charger as well.

Common causes of battery swelling include:

1. Overcharge conditions which accelerate parasitic reactions between the electrodes and electrolyte, with release of heat and gases.
2. Poor cell quality and design with low anode to cathode stoichiometric ratios, particulate contamination
3. Mechanical damage to electrodes induced either during cell assembly or from the product application
4. Excessive temperatures (Do not leave your cell phone inside your car)
5. Deep discharge of cells

reference: Why Do Lithium-Ion Batteries Swell?

There is nothing to suggest the charger may be implicated in any of these failures. The “charger” is nothing more than a regulated DC power supply. The charge circuitry is contained inside the battery enclosure and includes over voltage protection.

 

[DanMan32]

Agreed. I was going to say that myself.

However a third party charger could have too low a voltage that you don't get full capacity. But that's for another thread.

With the battery I noticed had swollen before flying, just enough that latching was difficult, I flew it in controlled conditions: not too high and not too far. No or minimal loss of capacity.
At the very least the two with some swelling can be used for non-flight AC management and as a USB battery pack.

 

[bktodd80]

There is nothing to suggest the charger may be implicated in any of these failures. The “charger” is nothing more than a regulated DC power supply. The charge circuitry is contained inside the battery enclosure and includes over voltage protection.

Well, if the charger is made of poor quality, it could overcharge the battery if the battery has been environmentally damaged, which would then overheat and could leak. Also, if the standard that the 3rd party charger is built to is at lower standards than aviation standards, a RC car battery charger for example, it could just be a manufacturer defect.

I agree with you that the battery has under and over-voltage protection. Sorry, but I'm a trust but verify or replace kind of guy.

We could go at this all day, but I was just recommending to swap out the charger to minimize the chance of it being a culprit. You could bench test the charger and verify it's good that way, since we are talking about adhering higher standards than just typical every-day consumer electronics, right?

I've seen some crazy engineered military-grade batteries loose their protection functions and the charger was bad also, which caused it to damage equipment.

 

[gnirtS]

Still doesn't explain how a charger is only affecting batteries made in July and August 2018 and batteries bought after that time work on the same charger.
For the 20+ people on this forum alone with the issue.

 

[WithTheBirds]

Well, if the charger is made of poor quality, it could overcharge the battery if the battery has been environmentally damaged, which would then overheat and could leak. Also, if the standard that the 3rd party charger is built to is at lower standards than aviation standards, a RC car battery charger for example, it could just be a manufacturer defect.

I agree with you that the battery has under and over-voltage protection. Sorry, but I'm a trust but verify or replace kind of guy.

We could go at this all day, but I was just recommending to swap out the charger to minimize the chance of it being a culprit. You could bench test the charger and verify it's good that way, since we are talking about adhering higher standards than just typical every-day consumer electronics, right?

I've seen some crazy engineered military-grade batteries loose their protection functions and the charger was bad also, which caused it to damage equipment.

Yes it's true faulty equipment can cause damage, obviously. My point was and remains that it is very unlikely faulty charge power supplies might be found to be the cause of the failures being discussed her. Probably not any but certainly not most or all.

 

[DanMan32]

There's really not much for the chargers to sense to prevent overcharge. They're just power supplies. They could be under voltage/current, but that would reduce available charge on the battery.