Anybody with battery swelling on M3 yet?

[christangey]

Just wondering on this as here in the Australian desert you get used to losing at least a couple of batteries on the M2P over a summer (and on the old Mavic 1), not ideal but it happens. If the internally-mounted M3 batteries do the same does that mean they will get seriously stuck inside the aircraft? Of course when the battery got swollen on the M2P it sometimes caused it to pop off in mid-air and crash the aircraft. By solving that problem by putting the battery inside the M3 are they potentially causing another problem? Asking for a friend.

 

[old man mavic]

simple answer is probably best not to leave a battery in the drone when not in use
any lipo will swell if subject to high temps as gas is expelled from the cells

 

[christangey]

simple answer is probably best not to leave a battery in the drone when not in use
any lipo will swell if subject to high temps as gas is expelled from the cells

Not sure, understandably, if you would know a lot about flying in heat being in Wales The swelling often happens in mid-flight so in the M3's case it would be too late by then.

 

[old man mavic]

@christangey you are correct we dont enjoy the extreme hot temps that can be had in the southern hemisphere ,but even if the battery did swell slightly during flight it should be able to be removed from the drone after it has cooled down i have not had the opportunity to have a close look at the M3 battery but if it is fully enclosed in a hard case unlike other batteries that have a soft surface to allow for expansion then it will most likely have a venting system to prevent the case from becoming distorted during use

 

[slup]

Seems to be a bit early to ask that ... the M3 haven't been out for more than 4 weeks, if batteries had started to swell already they either have been brutally abused or they are wrongly designed/manufactured.

But as said ... all batteries will swell, some more than others. The consequence of that can either be that they dislodge from the craft or get stuck inside ... in both cases much depending on how much swelling the battery compartment can take before the battery "outgrows" it.

And if it's really hot where your friend intends to fly I recommend him to follow what's stated in the DJI Mavic 3 Safety Guidelines ...

 

[christangey]

@christangey you are correct we dont enjoy the extreme hot temps that can be had in the southern hemisphere ,but even if the battery did swell slightly during flight it should be able to be removed from the drone after it has cooled down i have not had the opportunity to have a close look at the M3 battery but if it is fully enclosed in a hard case unlike other batteries that have a soft surface to allow for expansion then it will most likely have a venting system to prevent the case from becoming distorted during use

True, and I hope you are correct. In the case of the M1 and M2 batteries they certainly did "unswell" to a point. It was all a bit hit and miss though.

 

[christangey]

Seems to be a bit early to ask that ... the M3 haven't been out for more than 4 weeks, if batteries had started to swell already they either have been brutally abused or they are wrongly designed/manufactured.

But as said ... all batteries will swell, some more than others. The consequence of that can either be that they dislodge from the craft or get stuck inside ... in both cases much depending on how much swelling the battery compartment can take before the battery "outgrows" it.

And if it's really hot where your friend intends to fly I recommend him to follow what's stated in the DJI Mavic 3 Safety Guidelines ...

View attachment 139680

The "friend" bit was a joke! It's all very well to go by that advice but if we did we would hardly fly in summer. A big part of my business is 4K stock footage for broadcasters like BBC, NHK etc. and to get a certain shot sometimes it is like the SAS motto "Who dares wins" and we are prepared in rare circumstances to risk not just the battery but the aircraft itself to get a shot. One example was chasing a huge dust devil across an outback plain in plus 40 temps, something I had been wanting to capture for a very long time. I got the shot, but the battery was unusable after that despite me trying to bring down the swelling by immediately holding it against the 4WD aircon vent on full blast. But I knew that was the likely outcome from the risk. In the case of the M3 that amount of swelling wouldn't allow it to be removed in the first place I suspect, even after it cooled down. Just putting the question out there but as 'old man mavic' points out DJI may have a design that has solved the swelling of the M1 and M2 batteries, time will tell.

 

[Yogi053]

The "friend" bit was a joke! It's all very well to go by that advice but if we did we would hardly fly in summer. A big part of my business is 4K stock footage for broadcasters like BBC, NHK etc. and to get a certain shot sometimes it is like the SAS motto "Who dares wins" and we are prepared in rare circumstances to risk not just the battery but the aircraft itself to get a shot. One example was chasing a huge dust devil across an outback plain in plus 40 temps, something I had been wanting to capture for a very long time. I got the shot, but the battery was unusable after that despite me trying to bring down the swelling by immediately holding it against the 4WD aircon vent on full blast. But I knew that was the likely outcome from the risk. In the case of the M3 that amount of swelling wouldn't allow it to be removed in the first place I suspect, even after it cooled down. Just putting the question out there but as 'old man mavic' points out DJI may have a design that has solved the swelling of the M1 and M2 batteries, time will tell.

Chris, as you are well versed in the use of drones, especially the M2P, can you hazard a guess as to how many charges you can expect to get from the batteries if used in the 'correct' manner ie flying in the temperatures recommended by Dji?
Maybe an impossible question to answer, but I had to ask as you probably have a vast experience in your line of work.

 

[christangey]

Chris, as you are well versed in the use of drones, especially the M2P, can you hazard a guess as to how many charges you can expect to get from the batteries if used in the 'correct' manner ie flying in the temperatures recommended by Dji?
Maybe an impossible question to answer, but I had to ask as you probably have a vast experience in your line of work.

Ha! While I appreciate you having faith in my knowledge Yogi, I regret to say I rarely use my batteries in the "correct" manner, ever! But of course I'll take a guess anyway I would suspect if you ALWAYS flew it home at say 25% and at 20C temperatures you should be able to guarantee 200 cycles, but in reality I think it could be more like 400. A bit "how long is a piece of string? question though, as you know!

 

[Deleted member 103366]

If cooling deflates batteries what about an Ice chest etc, filled with frozen cooler packs? They might get the temperature sub zero.

 

[slup]

If cooling deflates batteries...

Gases generated in batteries, making them swell ... aren't anything that can be cured. It's one thing if the swelling is very minor when the gases is really hot & by cooling them down the internal pressure decrease which takes away some of the visual signs of swelling ... another is that the gases is still there, heat everything up & the swelling comes back.

Furthermore swelling is a clear sign of a electrolyte break down ... this usually increase the internal resistance in the battery ... which in turn makes the battery even hotter during amp draw, generating further break down & swelling. A battery that have started to swell will just be more & more prone to generate internal heat --> electrolyte break down --> increased internal resistance & gas generation --> swelling ... & on and on.

 

[Deleted member 103366]

Sorry I should have said "the larger reduction in gas volume might make removal of a stuck battery easier". I was not commenting on restoring the health etc. of the battery, merely temporarily reducing its swelling.

 

[wco81]

Last thing the M3 needs, on top of the heap of other issues.

 

[BlairAir]

Someone with deep knowledge of battery design would be able to answer many questions posed here. For example, the thought that DJI may have found a way to vent the M3 battery. I suspect that's not possible while remaining safe for the consumer. Another thought I had is also on the conversion of liquid/solids to gas. The reason swelling can be reduced somewhat by cooling is obviously the gas reverting to a liquid state, so the gases would not still be present, as theorized, but the stability of the electrolytic processes would be affected. One reviewer, I think Dustin Dunnill who has a lot of experience with many designs, noted that the M3 batteries do not appear to even be LiPo, but Li-ion, made up of cylindrical cells. If true, that may be one of the "solutions" DJI implemented to reduce the likelihood of swelling under extreme conditions.

 

[slup]

...the thought that DJI may have found a way to vent the M3 battery. I suspect that's not possible while remaining safe for the consumer.

Venting would be very hard to accomplish ... no outside air & moist can be allowed to enter the sealed batteries during any circumstances as that will start up a thermal runaway reaction with severe gas generation & heat... mainly destroying the battery with a big risk for a fire. That's why it's very dangerous to puncture a battery.

...Another thought I had is also on the conversion of liquid/solids to gas. The reason swelling can be reduced somewhat by cooling is obviously the gas reverting to a liquid state

That's not correct at all ... gases in a lithium battery is generated through a process called electrolyte decomposition, this decomposition is what happens when the electrolyte chemically breaks down. So in a lipo battery, as the electrolyte breaks down you end up with lithium and oxygen. This forms lithium oxide on the anode and cathode (increasing the internal resistance), you also end up with excess oxygen that doesn’t adhere to the anode or cathode. This excess oxygen together with other gases like carbon dioxide (CO2) and carbon monoxide (CO) is part of what causes a battery to swell. None of these gases will revert to "solid" form when cooled down ... the slight deswelling you possibly can see is plainly a internal pressure decrease when the temp gets lower.

...M3 batteries do not appear to even be LiPo, but Li-ion, made up of cylindrical cells. If true, that may be one of the "solutions" DJI implemented to reduce the likelihood of swelling under extreme conditions.

Both LiPo & LiIon is equal affected by electrolyte decomposition with following gas generation ... the difference is that LiPo usually are packed in soft pouches & the LiIon in solid containers ... Don't really know what is to prefer, a soft pouch that can swell without bursting or a solid that will have a huge increase in the internal pressure greatly increasing the risk for the battery to burst open with following thermal runaway reaction.

 

[Smooth Rhythm]

Asking for a friend.

Yes, I suspected as much, that it wasn’t true. I just don’t understand why people use that line, since in almost every case I suspect it’s not true. smh … Safe and happy flying, Enjoy!

 

[akdrone]

If cooling deflates batteries what about an Ice chest etc, filled with frozen cooler packs? They might get the temperature sub zero.

I think all my flights have been at below 0F and can attest ...no swelling thus far LOL.

 

[RocketBrew]

I am seeing slight "sponginess" in all six of my M3 batteries. Even those with only a few charges. I didn't notice it until I had already charged all of them at least twice.

So far, they are not "puffy" or swollen as I have seen with dozens of Phantom 4 Pro batteries over the years. Any sign of puffing and they were immediately retired. It also is not very hot yet here in the Arizona desert...

I have to admit I run my batteries hard to get every bit of flight time from them.

	Total Charges	Max Temperature	Avg Airtime
Battery #39 M3C	3	123.3°f	23m 18s
Battery #38 M3C	4	120.6°f	24m 51s
Battery #37 M3C	5	117.0°f	20m 00s
Battery #36 M3	6	126.7°f	23m 28s
Battery #35 M3	11	135.3°f	23m 33s
Battery #34 M3	12	126.7°f	16m 34s

 

[LV2FLY]

One reviewer, I think Dustin Dunnill who has a lot of experience with many designs, noted that the M3 batteries do not appear to even be LiPo, but Li-ion, made up of cylindrical cells. If true, that may be one of the "solutions" DJI implemented to reduce the likelihood of swelling under extreme conditions.

The published specification of the Mavic 3 battery is a 4 cell Lithium Polymer battery. DJI does not manufacture its own cells due to R&D costs and manufacturing scale to produce So, therefore, DJI is sourcing cells batteries from either one of the two largest worldwide producers or one of the many China-based LiPo batteries manufacturers. So at the end of the day, DJI has to work with the specifications provided by the manufacture.

Specifications
Model: BWX260-5000-15.4
Capacity: 5000 mAh
Battery Type: LiPo 4S
Charging Temperature: 5° to 40° C (41° to 104° F)
Max Charging Power: 65 W

 

[BlairAir]

Venting would be very hard to accomplish ... no outside air & moist can be allowed to enter the sealed batteries during any circumstances as that will start up a thermal runaway reaction with severe gas generation & heat... mainly destroying the battery with a big risk for a fire. That's why it's very dangerous to puncture a battery.

This was really good to learn. However, in spite of it not being practical, possible or safe under current manufacturing methods, that's not what I was curious about venting. Vents are one way pressure valves. Not punctures or exchanges of pressure. I am not really surprised they aren't possible though.

That's not correct at all ... gases in a lithium battery is generated through a process called electrolyte decomposition, this decomposition is what happens when the electrolyte chemically breaks down. So in a lipo battery, as the electrolyte breaks down you end up with lithium and oxygen. This forms lithium oxide on the anode and cathode (increasing the internal resistance), you also end up with excess oxygen that doesn’t adhere to the anode or cathode. This excess oxygen together with other gases like carbon dioxide (CO2) and carbon monoxide (CO) is part of what causes a battery to swell. None of these gases will revert to "solid" form when cooled down ... the slight deswelling you possibly can see is plainly a internal pressure decrease when the temp gets lower.

Also really good info. But wouldn't any pressure decrease be a reduction of gas, by conversion to solid or liquid? If gas forms pressure in the first place? I guess what I'm asking is, are there other contributors to the cell's pressure from temperature increase, beyond that from decomposition?