Swelling Battery caused Crash

[Dan C]

UPDATE: Tonight could of been disastrous. I could of lost my Mavic 2 Zoom. I know some of my 5 batteries are displaying battery buldge. As mentioned in one of my above posting I have only 5 batteries. I numbered them 1-5 with 5 the newest one bought. #1 battery came with the AC. They seem to be dying with #1 the worst and with that said #1 & #2. are most likely going to die out before #3, 4. And 5.... BATTERY #2 Popped out of the chassis with the AC hovering about 2 feet above ground. The drone died and I watched it in horror. The #2 battery clicked in place with a slight click sound. I had a bad feeling so I let it hover in place. The battery heated up until it expanded enough to unmount itself and I watched it happen. What if I was 399 feet in altitude and 1000 feet out.. I currently have 4 batteries with a good possibility of retiring the #1 battery.

NEVER FLY WITH BULGED BATTERIES

You are lucky that the worst you experienced is the battery falling out of your drone.

Folks, part of your pre-flight inspection should be the batteries. If they are bulging, they must be discarded; they are faulty and could catch fire. Everything I've read about LiPo fires suggests you really don't want to have one.

 

[Thomas B]

NEVER FLY WITH BULGED BATTERIES

You are lucky that the worst you experienced is the battery falling out of your drone.

Folks, part of your pre-flight inspection should be the batteries. If they are bulging, they must be discarded; they are faulty and could catch fire. Everything I've read about LiPo fires suggests you really don't want to have one.

Also recommend inspecting for bulging post flight when changing batteries. Early warning.
As stated before, you should not fly with a battery that has or currently exhibits a bulged lower surface.
If you bulged batteries are < 6 months old contact DJI ASAP to secure a replacement.

 

[gnirtS]

What are the manufacture dates of these batteries? (Can get it on Go4 or flight logs/airdata)

There seems to be a growing trend of early-made batteries become suddenly swollen and unusable without any user fault.

 

[HarrySmooth]

UPDATE: Tonight could of been disastrous. I could of lost my Mavic 2 Zoom. I know some of my 5 batteries are displaying battery buldge. As mentioned in one of my above posting I have only 5 batteries. I numbered them 1-5 with 5 the newest one bought. #1 battery came with the AC. They seem to be dying with #1 the worst and with that said #1 & #2. are most likely going to die out before #3, 4. And 5.... BATTERY #2 Popped out of the chassis with the AC hovering about 2 feet above ground. The drone died and I watched it in horror. The #2 battery clicked in place with a slight click sound. I had a bad feeling so I let it hover in place. The battery heated up until it expanded enough to unmount itself and I watched it happen. What if I was 399 feet in altitude and 1000 feet out.. I currently have 4 batteries with a good possibility of retiring the #1 battery.

Thank God you weren’t over the water! This is a serious factory flaw that DJI needs to address!

 

[silverdragon]

I should of mention this earlier, if I hold the battery up to eye level and hold the battery so the bottom is now the top I see a slight and I mean slight buldge. A non-trained eye may over look the buldge but I see it. Its ENOUGH to offset the battery shape to disconnect the 2 locking tabs. The battery in question has 82 charges and shows it's still functioning OK.

I had a hard time trying to wrap my head around why batteries are falling out of a drone. I know now if you dont get the loud hard click when installing the battery into the AC theres a chance of losing the battery in flight.

I use this now on all my batteries and I have the LumeCube strobe mounted

 

[GadgetGuy]

I should of mention this earlier, if I hold the battery up to eye level and hold the battery so the bottom is now the top I see a slight and I mean slight buldge. A non-trained eye may over look the buldge but I see it. Its ENOUGH to offset the battery shape to disconnect the 2 locking tabs. The battery in question has 82 charges and shows it's still functioning OK.

I had a hard time trying to wrap my head around why batteries are falling out of a drone. I know now if you dont get the loud hard click when installing the battery into the AC theres a chance of losing the battery in flight.

I use this now on all my batteries and I have the LumeCube strobe mounted

Thanks for the Pgytech accessory suggestion. Will it still attach properly if the battery is swollen, or is attaching the accessory your final test for good and sufficient battery connection contact?

 

[silverdragon]

Yes it will attach. But you know the drill on bulging batteries. I use it on all my good batteries, just for safety measures.

 

[GadgetGuy]

Yes it will attach. But you know the drill on bulging batteries. I use it on all my good batteries, just for safety measures.

Thanks for sharing that! I have the accessory, but don't yet have anything I need to mount on it. It's a good an alternative, or even a supplement, to the rubberized Velcro straps around the fuselage over the battery, should any of my M2 batteries develop any swelling later on.

 

[DanMan32]

Because they can catch fire, and by all accounts, LiPo fires are very difficult to put out.

The charge current the smart battery will allow is not very high compared to what the cells could normally be charged at, and discharge under the use I described is also much lower than capacity. Also smart battery has temperature sense to prevent overheat during charge/discharge.

 

[DanMan32]

Don't do that. I've read tons of forum posts and watched lots of videos about this. The consistent message is to store them within the recommended tenperature range (which I cannot remember off the top of my head, except to recall that with my A/C I keep my apartment at about 24C, and that's perfect for these batteries), and always discharge them to below 50%, but don't let them discharge completely either (running your batteries down to 0%, for example, is a great way to severely shorten their lifespan).

They are intelligent batteries, and will self-discharge (to protect themselves) after several days if you store them fully charged, but this generates heat, so if your storage area isn't nice and cool, you may also exceed their storage temperature.

Now, I don't personally know if this is true, but it seems to be the official position, therefore if you ignore it, DJI has a strong position from which to refuse replacement if it is found they were stored fully charged, or outside of recommended temperatures. Your call.

Self discharge current is quite low. Takes 2 days to discharge 40%. It won't overheat during discharge. You'd be charging it at a much greater rate and even then they don't get very warm.

 

[DanMan32]

UPDATE: Tonight could of been disastrous. I could of lost my Mavic 2 Zoom. I know some of my 5 batteries are displaying battery buldge. As mentioned in one of my above posting I have only 5 batteries. I numbered them 1-5 with 5 the newest one bought. #1 battery came with the AC. They seem to be dying with #1 the worst and with that said #1 & #2. are most likely going to die out before #3, 4. And 5.... BATTERY #2 Popped out of the chassis with the AC hovering about 2 feet above ground. The drone died and I watched it in horror. The #2 battery clicked in place with a slight click sound. I had a bad feeling so I let it hover in place. The battery heated up until it expanded enough to unmount itself and I watched it happen. What if I was 399 feet in altitude and 1000 feet out.. I currently have 4 batteries with a good possibility of retiring the #1 battery.

There's a thread specifically about the M2 batteries. What does the app report as the manufacture date of the batteries that have bulges?
So far we're only seeing those with manufacture dates 2018-08 or older.

 

[DanMan32]

I looked into those straps. 16mm is too wide to avoid bottom sensors if you put them on the ends, and putting them in the middle hits the latch.
If using velcro, best have them on the connector side. I'll be putting them on both sides.

 

[GadgetGuy]

I looked into those straps. 16mm is too wide to avoid bottom sensors if you put them on the ends, and putting them in the middle hits the latch.
If using velcro, best have them on the connector side. I'll be putting them on both sides.

Thanks for clarifying. I'll use the straps on something else. The PGYTECH mount above will do a better job securing the battery. There is always gaffers tape which leaves no residue. I even used gaffers tape for a month to patch a severely cracked motor mount on a P3P, until it broke all the way through, and cascaded onto the beach, motor and prop hanging by only the wires, unable to provide lift!

 

[silverdragon]

Thanks for sharing that! I have the accessory, but don't yet have anything I need to mount on it. It's a good an alternative, or even a supplement, to the rubberized Velcro straps around the fuselage over the battery, should any of my M2 batteries develop any swelling later on.

I mounted the LumeCube Strobe on mine. I gave it 2 functions. Secure battery and Strobe....it works fine. I made it habit to use that accessory. Secured battery means there is a better chance of Drone survival .

 

[GadgetGuy]

I mounted the LumeCube Strobe on mine. I gave it 2 functions. Secure battery and Strobe....it works fine. I made it habit to use that accessory. Secured battery means there is a better chance of Drone survival .

Anything that helps secure a battery is definitely a benefit, if the original latching mechanism is at risk. At least on the M2, with the cradled battery on top, the weight of the battery isn't actively pulling it out, like in the Mavic Air, with the battery underneath! I have the LumeCube too. Might start using it. However, the built-in M2 Landing Lights that are fully controllable from the RC at full range have been better for me up until now.

 

[gnirtS]

5 more July and August batteries to add from this thread: Mavic 2 Pro Overheated?

 

[GadgetGuy]

5 more July and August batteries to add from this thread: Mavic 2 Pro Overheated?

Good job! Still waiting for a report of significant M2 swelling on a later Production Date, (except those where the battery was deliberately drowned to sell a wetsuit! ?).

 

[gnirtS]

Its looking more and more likely. As time goes on you'd expect a consistent number of later date batteries reported but this simply doesnt seem to be happening.
Same size wise now a rough count i've got 35 or more swollen batteries. You could argue its a tiny figure but for me so far,the telling thing is ALL are August or July 2018.

 

[7thstring]

DJI are seemingly replacing swollen batteries for free, recognizing they could cause crashes, I even know of at least a youtube video about a DJI endorser reporting that.

It's a very bad design flaw from their end and very dangerous. While they cannot control the swelling, they should "allow" some tolerance in the chassis, instead of having an entirely flat surface.

It's pointless saying that the pilot should recognize the swelling and avoid flying, because the swelling could as well occur during flight, as the drone heats up.

My lawyer suggests a class action.

 

[gnirtS]

DJI are seemingly replacing swollen batteries for free, recognizing they could cause crashes, I even know of at least a youtube video about a DJI endorser reporting that.

Myself and others just got a blunt "its outside 6 months so nothing" response off them. One person appears to have been offered 20%.
In some cases they've asked for the batteries to be sent back (illegal in most countries to ship damaged Lithium batteries!).