Swollen Batteries

[Mr Shamrok]

The further clarification of your use case here does nothing to further advance or clarify the potential misinformation- specifically with respect to the effect on service life and performance of storage voltage for LiION chemistry.

What my or your opinion might be is irrelevant. The consensus of the experts and cell manufacturers is that storage at full charge should be avoided where possible. The fact you might have observed no ill effects in your specific case is also of little value. I know someone who drove his car 5 times further than the recommended service interval for an oil change and he tells everyone the manufacturer and oil company claims can be safely ignored.

Storage at full charge does have a negative effect on service life. The best practical storage SOC is somewhere below 40% however 50-65% does provide a safety margin for those who don't routinely check the charge state in storage. Frequent use at an operating temperature (not ambient) of 50C will have no significant adverse impact service life, particularly in any or the DJI models where discharge C rate is well below 5 (in sport mode).

To close the topic of "battery storage", I use this instruction here;https://dl.djicdn.com/downloads/Mav...igent_Flight_Battery_Safety_Guidelines_EN.pdf.
I got the impression that you inattentively read above what I wrote.
In general, here we are talking about the reasons for the bloating of the battery, and what can be done about it. I want to advise the author of this post NOT to use bloated batteries because at any time they can turn off in the air and he may lose his Drone. As for storage; read instructions of the official DJI website, I indicated the link, although I wrote practically the same without the link. Read carefully what I wrote again. AND CAREFULLY read the instructions from the official website on how to store the battery, and then you will understand what I wrote. Battery after flights it is NECESSARY to charge at least up to 60%. (I repeat again) I charge the battery to 100%, and then after a few days the battery self-discharges (it loses several percent, and can only take charge when it is 95%), after which Before the flight, you recharge it, as indicated in the instructions, BEFORE THE FLIGHT. My batteries have been operating since 8/2018, and I have no problems with bloating or subsidence of the cells, and the flight time lasts from 22 to 26 minutes.

 

[WithTheBirds]

To close the topic of "battery storage", I use this instruction here;https://dl.djicdn.com/downloads/Mav...igent_Flight_Battery_Safety_Guidelines_EN.pdf.
I got the impression that you inattentively read above what I wrote.
In general, here we are talking about the reasons for the bloating of the battery, and what can be done about it. I want to advise the author of this post NOT to use bloated batteries because at any time they can turn off in the air and he may lose his Drone. As for storage; read instructions of the official DJI website, I indicated the link, although I wrote practically the same without the link. Read carefully what I wrote again. AND CAREFULLY read the instructions from the official website on how to store the battery, and then you will understand what I wrote. Battery after flights it is NECESSARY to charge at least up to 60%. (I repeat again) I charge the battery to 100%, and then after a few days the battery self-discharges (it loses several percent, and can only take charge when it is 95%), after which Before the flight, you recharge it, as indicated in the instructions, BEFORE THE FLIGHT. My batteries have been operating since 8/2018, and I have no problems with bloating or subsidence of the cells, and the flight time lasts from 22 to 26 minutes.

What I understood is that your intention is to keep your batteries at or close to 100% SOC. Perhaps you articulated your practice badly.

You may have a case where flight readiness is the priority and a loss in service life for you batteries is an acceptable tradeoff. So be it. A pack kept at 100% SOC will experience greater age related usable capacity loss than one stored at 40%. This is a very well known characteristic of the chemistry, it wasn't that long ago that the capacity difference exceeded 15%, it might well be less with current cells however it is still real. We also know that LiION cells are less stable at 100% SOC, the studies commissioned by the FAA seem to support this and give us confidence that the prescribed max charge state levels for LiION carried as air cargo should be strictly followed.

While it is probably lead to no ill effects there is no necessity or advantage in charging a LiION cell to 60% after a flight. If I land with a LiPO above 10% and expect to fly within a week of so I leave it like that. If I don't end up flying I will bring it up to 40%. That has been my practice long before DJI existed and with bare LiPO packs (dumb batteries) and has served me well. I have destroyed more than a few expensive batteries in the early days learning the hard way.

 

[Mr Shamrok]

What I understood is that your intention is to keep your batteries at or close to 100% SOC. Perhaps you articulated your practice badly.

You may have a case where flight readiness is the priority and a loss in service life for you batteries is an acceptable tradeoff. So be it. A pack kept at 100% SOC will experience greater age related usable capacity loss than one stored at 40%. This is a very well known characteristic of the chemistry, it wasn't that long ago that the capacity difference exceeded 15%, it might well be less with current cells however it is still real. We also know that LiION cells are less stable at 100% SOC, the studies commissioned by the FAA seem to support this and give us confidence that the prescribed max charge state levels for LiION carried as air cargo should be strictly followed.

While it is probably lead to no ill effects there is no necessity or advantage in charging a LiION cell to 60% after a flight. If I land with a LiPO above 10% and expect to fly within a week of so I leave it like that. If I don't end up flying I will bring it up to 40%. That has been my practice long before DJI existed and with bare LiPO packs (dumb batteries) and has served me well. I have destroyed more than a few expensive batteries in the early days learning the hard way.

Thank you, have you safe flights and clear skies.??

 

[old man mavic]

i have never owned a M2P or zoom ,but i think that in an attempt to increase flight time for the M2P over the MP1 or MPP ,DJI tried to pack a 4 cell lipo in a similar space to the 3 cell ones in the earlier models, also if you look at the bottom of a MPP or MP1 battery, you will notice that there is a space between the case frame and bottom of the cells that allows for some swelling during use without the worry of the pack being expelled from the drone, this is absent on the M2P packs they are almost flush with the bottom of the case

 

[Jonathan Burnett]

Bought my M2P back in August 2018 and got a total of 4 batteries. In those days there was not much written about batteries swelling and the causes, and I tended to keep them at 100% charge so I'd be ready to go. I think the default back then for auto-discharge was 10 days. Anyway about 9 months later, 3 of the 4 batteries were discovered to have swollen significantly whilst in storage. Then I read about the condition and knew not to fly with them any longer and I knew they were out of their 6-month warranty so I figured I was screwed.

But, I didn't throw them away. Instead I put them into a LiPo bag and closed it up and put it away and brought 3 new batteries, which I now manage like the advice given here. Well about 9 months after I put them into the LiPo bag, I opened it up to discover that the batteries had deflated and were no longer swollen. So I performed a deep discharge/recycle of them and brought them back up to full charge and they stayed flat! So gingerly, I test flew each battery and they work perfectly fine. Been doing this now for more than 6 months and they continue to work like they were never swollen.

I can't say everyone's swollen batteries will behave like my 3 but apparently the outgassing that caused them to swell, either eventually seeped out or chemically the gas was reabsorbed into the chemistry (if that's even possible). So perhaps if batteries swell on you, you might be able to restore them by giving them a long rest but you'll not want to presume they can't explode so a LiPo bag at a minimum is a good idea.

Hope this helps someone!

Jonathan

 

[Aether]

Definitely good advice!

After putting the batteries in the freezer as mentioned I decided to do a test flight today. There were absolutely no issues with the flight (voltage remained steady the entire time), although when I landed the battery was quite swollen again.

I guess I could repeat this process each time, although I don’t think the fact the battery is swelling up during flight is a good thing at all. I might try getting one of the storage bags as the above post mentions. Any suggestions on brand?

Thanks!

 

[Jonathan Burnett]

So all 3 of my recovered batteries will show a slight puffiness after a flight which subsides after the battery cools off. The state of charge seems to have no effect on the puffiness. I am surmising then that within the seal cells, there must still be some gas that hasn't yet leached out and when the battery gets hot, this gas expands. Fortunately the puffiness is very slight and not enough to dislodge the battery when snapped into the M2P. Still, I keep an eye on them and very carefully manage their charges. Hopefully the residual gas will completely escape in the future but they are quite functional for now.

 

[SkyeHigh]

My chemistry is a bit rusty (pun intended) but I suspect the oxygen will continue to corrode the internal battery terminals eventually reducing battery life further.

For anyone interested there are a number of videos showing the LiPo battery manufacturing process on YouTube. Just search for ‘LiPo Manufacturing’.

 

[Paulgrace]

I had the same problem with a swollen battery with my Mavic Air . In flight at about 80 ft high 50 ft from the beach over water the message read extreme battery failure and began to immediately land . Ran and swam to retrieve it but came up short less than a foot before it sunk to the bottom. Miraculously the SD info was intact except the last video which I wish I had if me frantically trying to save my drone. The moral of the story never fly with swollen batteries use it for editing and benchwork.

 

[El Dedos]

Original 3 batteries for my Mavic 2 Zoom swelled. DJI would not honor the "Care refresh" so I ditched the batteries and DJI. For a difference of $20 they refused to replace even one of the batteries. I have replaced 2 of them but will never buy a DJI product again. These were defective units and they will not acknowledge it. Good luck.
They were stored according to proper guidelines. Still swelled. Defective. Period!

 

[MGVision]

Original 3 batteries for my Mavic 2 Zoom swelled. DJI would not honor the "Care refresh" so I ditched the batteries and DJI. For a difference of $20 they refused to replace even one of the batteries. I have replaced 2 of them but will never buy a DJI product again. These were defective units and they will not acknowledge it. Good luck.
They were stored according to proper guidelines. Still swelled. Defective. Period!

That is why they gave us only one year warranty. They knew that after this time there will be problems with batteries. Thats how this world works - it is all about money.

 

[apeel]

I live in Arizona where the temperature gets to around 110 F this time of year. I hadn’t flown my drone for a few weeks and noticed the batteries don’t seem to fit within the drone very well. I went for quick flight and upon landing and removing one the battery I noticed it was very swollen at the bottom.

I’m guessing my batteries are ruined now? The batteries are around a year and a half old. What can I do in this situation especially considering where I live?

FFS!

I live in Texas so I understand the challenges of temperature extremes in the Southwest. As I like to take road trips with my wife, I was particularly concerned with leaving the batteries in the car, when stopping over somewhere for a meal, etc as temperatures can go up high real fast in a closed car. So when I purchased my Mavic 2 Zoom, I also got a mini-fridge like the one below. It can be powered by 110VAC, USB, or 12v lighter adapter, all options that are included in the package. I remove the shelf inside and it has room to store 3-batteries + remote controller + 10,000ah power bank. Very handy!

I use the 12v lighter adapter when we are driving, which keeps the temperature in the fridge down to around 60F - 70F (measured with an infrared gun) . When I shut the car off, the fridge also shuts off as my outlet needs to have the car running for it to generate the 12v output. But if you leave the fridge door closed, it stays cool and safe for the batteries for quite some time even with the car off.

Incidentally, in order to save money, I also keep our house at 78-80F during the summer. So I actually keep the batteries in the fridge even when in the house. In this case I run the fridge using USB as it will not get quite as cold inside as when operating it on 110VAC. Again, while in the house, I find that they fridge stays at a nice 60F - 65F inside.

To make sure there is no condensation on the batteries or remote controller while in the cooler, you can (and should) store them in a sealed plastic bag. I use the fireproof LiPo battery bags (link below) for the batteries, and put some moisture absorbing gel packs in each bag to pick up any extra moisture that may occur. So far, I have not had problems with moisture or bulging .. knock on wood.

Here are some Amazon links (no affiliates) of the fridge, LiPo bags and Gel Packs that I use:

Cooluli Classic Black 4 Liter Compact Cooler Warmer Mini Fridge with AC/DC/USB Power - Great for Bedroom, Office, Car, Dorm - Portable Makeup Skincare Fridge

Anbee Mavic 2 Lipo Battery Safe Bag Fireproof Storage Bag for DJI Mavic 2 Zoom/Pro Drone (Small, 3-Pack)

Dry & Dry 3 Gram [50 Packs] Food Safe Silica Gel Orange Indicating(Orange to Dark Green) Mixed Silica Gel Packs Desiccant - Food Safe Silica Packets for Moisture Absorber Silica Gel Packets

 

[DroneFlyerNick]

3 of my 7 mavic 2 batteries are swollen. I contacted DJI just prior to when the world shut down due to Covid. They replied back to me requesting I send them a video of the 3 batteries placed on a flat surface and I touch the corners of the battery to prove that they are each swollen. I said F/U, Why don’t you look at my purchase history of the batteries you’ve shipped me and decide. That was in February, I’m still waiting for a reply. Meanwhile I have 3 paperweights for sale.

 

[MGVision]

3 of my 7 mavic 2 batteries are swollen. I contacted DJI just prior to when the world shut down due to Covid. They replied back to me requesting I send them a video of the 3 batteries placed on a flat surface and I touch the corners of the battery to prove that they are each swollen. I said F/U, Why don’t you look at my purchase history of the batteries you’ve shipped me and decide. That was in February, I’m still waiting for a reply. Meanwhile I have 3 paperweights for sale.

When you contacted dji, batteries were still on warranty?

 

[DroneFlyerNick]

When you contacted dji, batteries were still on warranty?

At the time I contacted DJI, 2 were 2 months past the warranty and the 3rd battery was not, but has since gone out of warranty. I knew DJI would not replace them, but I wanted to inform them only. Of all the DJI drones I have or have owned, Mavic 2 batteries are the worst. To this day, my 4 year old Phantom 3 advance batteries still maintains about 80% and I fly I this drone every other month. Same can be reported about my mavic pro.

 

[MGVision]

At the time I contacted DJI, 2 were 2 months past the warranty and the 3rd battery was not, but has since gone out of warranty. I knew DJI would not replace them, but I wanted to inform them only. Of all the DJI drones I have or have owned, Mavic 2 batteries are the worst. To this day, my 4 year old Phantom 3 advance batteries still maintains about 80% and I fly I this drone every other month. Same can be reported about my mavic pro.

And thats the best prove that mavic 2 series batteries are faulty.

 

[WithTheBirds]

3 of my 7 mavic 2 batteries are swollen. I contacted DJI just prior to when the world shut down due to Covid. They replied back to me requesting I send them a video of the 3 batteries placed on a flat surface and I touch the corners of the battery to prove that they are each swollen. I said F/U, Why don’t you look at my purchase history of the batteries you’ve shipped me and decide. That was in February, I’m still waiting for a reply. Meanwhile I have 3 paperweights for sale.

Let me get this right- DJI asks for video to evidence the claimed fault (this is how they handle battery problems, it’s not a fantastic idea to ship dodgy batteries back for inspection), you tell them to get F’d and then you are surprised they haven’t come back to you?

There might’ve some room for you to improve in your approach here....

Send them the video- you may be surprised what they offer....

 

[Aether]

After the trial and error of putting mine in the freezer to alleviate the swelling they started getting worse, so I had to bite the bullet and buy new batteries.