Hi guys,
I own a mavic 2 zoom for about 11 months now. I had the stock battery and the flymore combo. One of my batteries got swollen in a matter that it won't fit in the mavic 2 zoom.
I did some research on how to work around with this issue and what to do. On some forums I found that they need to be neutralized and disposed because they're dead.  I'm kinda curious thought for few days thinking of disposing this expesive battery. It came on my mind to open the battery without any knowledge and explore the issue by myself. I managed to open the battery case holding the 4 cells inside. With just open half of battery case open just to see the lithium cells. More curiosly I touch them and found they're pluffy sealed in a silver plastic bag. I decided to superficially make two pin holes on each cells with punching the silver sheet material, they expelled a fruity odor and all cells shunk in size as they normally are fitting in the case normally. I decided to give them a charge and took charge normally and make an shallow flight to verify if the battery got discharge quickly or any failure happens. So far the battery is normal.
Has anyone tried this?

That is risky, using a battery with cells like that could lead to a loss of your very expensive drone and not to mention possible injury.

I have heard and seen this done with phone batteries with success, weather I would chance it is another thing.

do not do this! You were quite lucky they did not catch fire as soon as you poked a hole in them!!!! I did this with a phone battery once and it instantly ignited and burned for about a minute, hot enough to melt the alu foil. It does not need a spark to ignite, contact with oxygen is all it takes.

stealther Posted at 9-12 21:53
do not do this! You were quite lucky they did not catch fire as soon as you poked a hole in them!!!! I did this with a phone battery once and it instantly ignited and burned for about a minute, hot enough to melt the alu foil. It does not need a spark to ignite, contact with oxygen is all it takes.

Thanks for your comment! Knowing this I fully discharged the battery to 0% before doing this.

This is a really bad idea, lithium cells are sealed for a reason. They will react with the oxygen in the air and you just created a pinhole to let air in.

I think it’s amazing the OP is still here answering questions lol.....

What you smelt was probably Lithium hexafluorophosphate from the electrolyte and some other gasses that may or may not be toxic, your lucky it didn't ignite and explode. At least you discharged it but still, fairly dangerous.

I wouldn't even use the battery, after something like that.

Jose C. Borrero Posted at 9-13 03:29
Thanks for your comment! Knowing this I fully discharged the battery to 0% before doing this.

That battery is a fire risk,  you should safely dispose of it.

I would never use that battery again and get it disposed of properly. When the pinholes finally let in oxygen, the batteries WILLcatch fire.

Hello and good day Jose C. Borrero. Thank you for reaching out and for the inquiry. I hope that you will get the best information from our valued DJI co pilots with regards to this matter. Just a friendly reminder that please do not fly your drone with swollen batteries this might lead to an accident during the flight. Have a safe and a happy flying always.

Get rid, professionally, ASAP!

The smell is a solvent called DEC (diethyl carbonate) it has a flash point of around 19c the gas you released is hydrogen, also volatile.

When these cells are produced they are done so in a very dry environment. sealed in vacuum chambers and then charged. This causes a reaction in the cell producing hydrogen. Which is removed in another step of the process.

If you open the cell, you will allow air to enter the cell which will contain moisture which is a killer of these types of cells.

There is potential for lithium crystals to grow between the anode and cathode which can damage the separators resulting in a very hot cell and ultimately a fire.

You need to dispose of these cells as soon as possible.

The electrolyte is very caustic and can produce HF a very nasty acid which in contact with skin will destroy the soft tissue and produce F-ions which when absorbed into the body are extremely toxic. While you would suffer burns the real damage is done by the f-ions.  

The battery is not normal if you punched two pinholes in each cell. If your battery won't fit in the Drone anymore, then you should know there is a problem with the battery. Suppose it fails in flight and falls from the sky and causes injury or damage? What if the battery catches fire in flight, or when it is sitting in your house between flights? I'm sure you were being careful when inserting the pin in the cells, but I have to agree that you were lucky this time.

Are you serious?? How old are you???

There are many posts here telling you,  the Orginal Poster ( OP )  to dispose of the battery......they are correct!!!

However, before doing so, the battery needs to be INERT, and NOT active in any way................please place in a SALT WATER solution for about a week, then throw away in the trash.

This will render the chemical components inside the battery INERT, and not volatile.

Randy

I read a lot about this issue here on the forum.
Hope DJI addresses this!

My mavic 2 zoom fly with No issues so far... I will report if the battery get damaged at last.

bumping this thread!

Jose C. Borrero Posted at 9-22 14:12
My mavic 2 zoom fly with No issues so far... I will report if the battery get damaged at last.

That battery is already damaged, do not use it if you like the enjoyment of owning a Mavic 2.
It will fail on you.
Period.

Battery died suddenly. Not holding more charges My other fly more combo batteries are start getting swell. In less than a year.

Because there was no automatic discharge prior to the latest update.  They've included it for 5 days.  I put 4.  With no automatic discharge they stay at nearly 4.40V for too long and swell.  Storage voltage is supposed to be around 3.8V.

To those with Smart Controllers, you need to use the Standard controller to get the batteries to update or refresh w/ each battery on the PC.

Of course there was automatic discharge before the last update. Fixed to 10 days.

How I do the update?

Jose C. Borrero Posted at 10-15 18:33
How I do the update?

You have to upgrade to the latest firmware which is .510 then go into the battery section and change it to 4 days but the default is 5 days.  If you just plan on flying the same day you can do 1 day.  For every battery, you need to change the days, unless you want the default of 5.

Corvus monedula Posted at 10-13 00:58
Of course there was automatic discharge before the last update. Fixed to 10 days.

It didn't have any automatic discharge I think.  I got into the Mavics a couple months before the update.

Corvus monedula Posted at 10-13 00:58
Of course there was automatic discharge before the last update. Fixed to 10 days.

Yes and 10 days is simply too long for a charged lipo....2 or 3 days os more like it. I never leave my lipos charged anyway only if i know i am going out...otherwise they stay at one full light and a blinking light.

Jimmy hoffa Posted at 10-17 02:22
Yes and 10 days is simply too long for a charged lipo....2 or 3 days os more like it. I never leave my lipos charged anyway only if i know i am going out...otherwise they stay at one full light and a blinking light.

I wonder what you do when you're not sure if you'll fly or not.

Let's see....  replacement batteries cost $159. Risk a $1500 - $1750 drone to try and keep using a compromised battery, to save $160 on another battery?

I mean, I wouldn't risk a sub $200 RC airplane on an old, puffy battery, and the airplane has at least some potential to glide in for a repairable landing if power is lost.

Li-Po batteries are nothing to fool around with, whether it's the high-tech batteries such as those for our drones, or simple batteries without additional electronic circuitry such as those I use with my planes. Trying to use them after they are compromised is a case of being penny-wise and pound-foolish.