Hello, I have Air 2S and two out of three batteries are bulging. Every battery has been used about 40 times and work normally.
Should I  be worried?
Have you got any suggestions?

I wouldn't use those batteries anymore.  It is a great sign that the batteries are failing.  I would purchase new batteries at this point.

Agreed - dispose of these and get new ones ASAP.

You can still fly them if they still fit. You won't get 100% flying time from those battery anymore, and normally they bulge, when stored fully charged or kept in warm places, as far as what I have learned...

You can still use them, but it is common practice to dispose of bulging batteries before they do some damage...

Hi there. Thank you for reaching out and we're sorry for the trouble. Can you please provide me the serial number of your swollen batteries via PM so we can check? Please keep us posted. Thank you.

How do u even tell its swelling up? I can't even tell sht. Lol. They are inside the plastic housing. I used lipo battery for RC cars. Those you can actually see each cells and when they swell you can actually see it.

djiuser_zKR5HFX3a2EC Posted at 5-25 18:16
How do u even tell its swelling up? I can't even tell sht. Lol. They are inside the plastic housing. I used lipo battery for RC cars. Those you can actually see each cells and when they swell you can actually see it.

Did you look at the picture the OP posted???

Burt37 Posted at 5-25 18:56
Did you look at the picture the OP posted???

Yep i did. Cant tell if they are swelling or not. Since all batteries are inside plastic case. Could be the angel op place the battieres at make one seem larger. To actually see the batteries swelling have to take the plastic cover off.

Burt37 Posted at 5-25 14:13
You can still fly them if they still fit. You won't get 100% flying time from those battery anymore, and normally they bulge, when stored fully charged or kept in warm places, as far as what I have learned...

You can still use them, but it is common practice to dispose of bulging batteries before they do some damage...

I don't keep them in hot places and I have DJI hardcase that I store them.

DJI Paladin Posted at 5-25 17:24
Hi there. Thank you for reaching out and we're sorry for the trouble. Can you please provide me the serial number of your swollen batteries via PM so we can check? Please keep us posted. Thank you.

PM Send Thanks.

djiuser_zKR5HFX3a2EC Posted at 5-25 18:16
How do u even tell its swelling up? I can't even tell sht. Lol. They are inside the plastic housing. I used lipo battery for RC cars. Those you can actually see each cells and when they swell you can actually see it.

It shows by looking at the downside as it is slightly curved.

djiuser_zKR5HFX3a2EC Posted at 5-25 21:07
Yep i did. Cant tell if they are swelling or not. Since all batteries are inside plastic case. Could be the angel op place the battieres at make one seem larger. To actually see the batteries swelling have to take the plastic cover off.

You will see bulging on the bottom of the battery where the black label is. I certainly wouldn't fly these batteries.

djiuser_zKR5HFX3a2EC Posted at 5-25 21:07
Yep i did. Cant tell if they are swelling or not. Since all batteries are inside plastic case. Could be the angel op place the battieres at make one seem larger. To actually see the batteries swelling have to take the plastic cover off.

Not at all. If you look at the first battery on the left of the picture, you can clearly see that the edge is no longer touching the table... Not all DJI batteries have room for the lipos to expand

LoveYou Posted at 5-25 23:45
I don't keep them in hot places and I have DJI hardcase that I store them.

But do you charge them to 100% and then stored them away?

LoveYou Posted at 5-25 23:46
PM Send Thanks.

Thank you for keeping us posted. We already respond to your PM, kindly please check your inbox. Have a nice day ahead.

Burt37 Posted at 5-26 13:16
But do you charge them to 100% and then stored them away?

Yes charge 100% and store to hardcase.

I think it would be dangerous to fly these batteries if they are swelling.  I have a friend of mine who had a swelling battery and the capacity of the battery decrease significantly, and the battery eventually failed in flight.  Luckily his drone survived to fly another day.  I wouldn't dare put my drone in harms way.

LoveYou Posted at 5-27 01:24
Yes charge 100% and store to hardcase.

Hi, I've had the same problem at a similar charge count. 39 charges and there is some swelling in the battries. The battry marked as 2 is swelling vs the one marked as 3. What did the DJI person advise you on this?

izzikio_rage Posted at 7-8 10:27
Hi, I've had the same problem at a similar charge count. 39 charges and there is some swelling in the battries. The battry marked as 2 is swelling vs the one marked as 3. What did the DJI person advise you on this?

DJI replied: Hi there. Thank you for reaching out. We are deeply sorry that you experiencing issues with your batteries. Sorry to tell you that the battery is out of warranty and can not be repaired. You are recommended to buy a new battery as these batteries are no longer safe to use.

I have some Lipos that have been bulged for more than 2 years in some of my large helis (6000 and 8000 mAh). The flying time has definitely shortened a bit, but they are fine... I eventually move those battery to my RC trucks, until they no longer rechargeable... So far, so good.. You definitely need to be careful, but not paranoid about it, just because a little bulge has developed into them...

Off course the retailer would suggest to replace them. They are a business and we have become a trow away society...

It goes without saying that if the battery no longer fit into the drone, then you have no choice... YMMV

Burt37 Posted at 7-8 13:52
I have some Lipos that have been bulged for more than 2 years in some of my large helis (6000 and 8000 mAh). The flying time has definitely shortened a bit, but they are fine... I eventually move those battery to my RC trucks, until they no longer rechargeable... So far, so good.. You definitely need to be careful, but not paranoid about it, just because a little bulge has developed into them...

Off course the retailer would suggest to replace them. They are a business and we have become a trow away society...

Thanks both, so I'm guessing for now it's avoid use or use for things like firmware updates on the ground

Found one more thread on this
https://forum.dji.com/thread-262432-1-1.html

Caused by heat and moisture and overcharging before storing

LoveYou Posted at 5-27 01:24
Yes charge 100% and store to hardcase.

Do you fly to low charge percentage?

Every time you go below 50% charge it shortens the number of charge cycles and increase swelling %.

There is exponential damage done to the battery every time you over discharge.

This unfortunately is a LiPo technology problem.

bjr981s Posted at 7-10 05:56
Do you fly to low charge percentage?

Every time you go below 50% charge it shortens the number of charge cycles and increase swelling %.

Several flights landing battery  +-15%

bjr981s Posted at 7-10 05:56
Do you fly to low charge percentage?

Every time you go below 50% charge it shortens the number of charge cycles and increase swelling %.

"Every time you go below 50% charge it shortens the number of charge cycles.. This unfortunately is a Lipo technology problem"

Actually, I'm sure that, this problem applies to nearly every battery on the planet, regardless of the chemical composition... The only advantage you have with LIpos is that they have no "memory effect" and because of that, the number of cycles tend to be a bit higher than with the old NiCad...

Here is a good article....

https://hobbiesdirect.com.au/blog/nimh-vs-lipo-rc-batteries

Burt37 Posted at 7-10 16:58
"Every time you go below 50% charge it shortens the number of charge cycles.. This unfortunately is a Lipo technology problem"

Actually, I'm sure that, this problem applies to nearly every battery on the planet, regardless of the chemical composition... The only advantage you have with LIpos is that they have no "memory effect" and because of that, the number of cycles tend to be a bit higher than with the old NiCad...

That's not a very good article and has quite a few errors. A more accurate comparison is between LiPo, LiFe and LiOn batterie. You would never use NiMH as a drone power battery. You would only ever use them as RX batteries. I flew RC Fixed wing nitro in the 80s and cycled my NiMh batteries very time the night before I flew and they had many more cycles than a LiPo.

My company sells Solid state drone batteries and they do not swell at all regardless of use or abuse.

bjr981s Posted at 7-10 19:59
That's not a very good article and has quite a few errors. A more accurate comparison is between LiPo, LiFe and LiOn batterie. You would never use NiMH as a drone power battery. You would only ever use them as RX batteries. I flew RC Fixed wing nitro in the 80s and cycled my NiMh batteries very time the night before I flew and they had many more cycles than a LiPo.

My company sells Solid state drone batteries and they do not swell at all regardless of use or abuse.

We all have our opinions, and that's good...

What chemical composition does you solid state battery uses?

So never charge to 100% never drain below 50% what are we supposed to fly with?

Noted on the broader advise if not flying with bulging battries and caring a lot for the battries

The Intelligent battery system prevents your batteries from being discharged to a dangerous level. 0% on the Fly app is probably closer to 20% of actual capacity. Watch this for proof -

Mobilehomer Posted at 7-11 09:55
The Intelligent battery system prevents your batteries from being discharged to a dangerous level. 0% on the Fly app is probably closer to 20% of actual capacity. Watch this for proof - https://youtu.be/Bre7z5oT-Sg

On the Fly app is 10%

LoveYou Posted at 7-11 10:50
On the Fly app is 10%

With DJI batteries, the chances to damage a battery while using it or charging them are pretty low... However, you can help to make the battery last even longer by following some of the suggestion mentioned in this thread...

Keep the battery stored in a cool place. HEAT is the enemy N.1
Don't charge to 100% unless you are using it the same day
Don't let them get too hot (flying in very hot days or during a software update)
Don't store them for long time (months) without checking their charge level
Only buy a number of batteries that can be effectively used by your flying habit and rotate them on a regular basis

I also notice people complaining on how much time it takes to charge those batteries... The longer it takes to charge, the cooler they stay, the longer they last...

A little bulging is not the end of the battery, it is the beginning of a degrading of power retention. They are consumable after all, and how long they last it is not written in concrete. Some batteries do better than others even within the same brand...

Finally, without getting too paranoid about it, if you can, store them in a fireproof container/bag...

I only had one Lipo exploding while charging and the $20 Lipo bag it was charging in it, saved my home. One Lipo battery out of possibly 350 batteries since the beginning, is not bad, but it does and can happen...

I now keep all my Lipos in army ammunition boxes.

Burt37 Posted at 7-11 15:21
With DJI batteries, the chances to damage a battery while using it or charging them are pretty low... However, you can help to make the battery last even longer by following some of the suggestion mentioned in this thread...

Keep the battery stored in a cool place. HEAT is the enemy N.1

100% correct.

Mobilehomer Posted at 7-11 09:55
The Intelligent battery system prevents your batteries from being discharged to a dangerous level. 0% on the Fly app is probably closer to 20% of actual capacity. Watch this for proof -

The 20% or 10% is to protect your drone from crashing not from damaging the battery.

The chemistry in the LiPo is stable when charged to its nominal voltage. Thats 3.7V per cell.

Voltages above that and below that the chemistry is effected exponentially to 100% and down to 0%  

Hence charge to 100% just prior to flight and recharge/discharge them to 3.7V as soon as you can.

Unlike normal batteries a LiPo has a threshold voltage of 3.3V per cell. This represents 0 charge.

So the full range is from 3.3V to 4.2 Volts, is 0 to full charge.

If you discharge a LiPo cell below 3.0 it is irreparably damaged.

Now to understand the DJI battery percentage operations you need to calibrate the gauge every 3 months. You will find this referenced in DJI battery operations procedures.

The Gauge is calibrated for a new battery. As the battery ages the parameters of the battery change through its charge range. As they age the stored energy of the battery is reduced.

The battery "Fuel" gauge does not represent the actual 0% charge. It is above that as DJI set a safety margin.

The process to calibrate the gauge is to discharge the battery in your drone till the drone will not power on. Then as soon as it cools immediately fully charge. Sitting at this low state is destructive to the battery. The gauge then calibrates from the fully discharged to fully charged state.

The gauge then gives you an accurate representation of the battery charge over the operational lifetime of the battery as it ages.

I have seen many posts here of members that have not followed this procedure on older batteries finding that when flying down to 30-20% of charge the battery quickly depletes in a mater of seconds and falls from then sky.

The other specific DJI LiPo issue that this resolves, is that it prevents the battery from fully discharging in storage.

The self discharge mechanism drops the DJI battery down to safe storage charge over a few days.

But the self discharge circuit is still measuring the battery voltage. I don't know exactly what the M(Ohms)/Volt rating of that circuit is but it does draw a small current. It will deplete the battery over a 3 to 6 month period shortening the life of the battery.

Yes I am or was an electronics engineer (Institute of Technology Sydney)

Hope this information is useful.

p.s. Forgot to mention. DJI Mostly use LiHVs in their drones not "Normal" LiPos They are more expensive and can be charged to 4.4V Per cell rather than 4.2
I have a perminent reminder in my Outlook Calander every 3 months to do a cycle on all my DJI drones.

I have a reminder every 12 months to check my other batteries (to top them up) that i use for 3D helicopters, Non DJI drones, Fixed Wing prop electric, Fixed Wing ducted fan, and sundry batteries for TXs Turbine power and Gas Fixed wing power. I have over 300 LiPos so the maintence is a PITA.

I still have in my inventory, Mavic 3 Pro, Mavic 3 Cine, Air 2s, Air 2 Air 1, Mavic 2 Pro, Mavic 2 Zoom, 2x Mavic Pro, Mini 3 Pro, Mini 2, Mini SE, Mini, 6x Spark, Avata and FPV drone. All wuth at least 3 batteries. Most with 4. Its a long task doing the maintenance. But I dont do the discharge as per DJI procedure. I dont fly the batteries down below 50% so they still operate as new batteries after many years of use. These are my personl drones not my company ones. These are too expensive for me to own.

Burt37 Posted at 7-10 23:03
We all have our opinions, and that's good...

What chemical composition does you solid state battery uses?

Here is a link that explains the technology reasonably well.

https://www.maketecheasier.com/solid-state-batteries/

The batteries are not cheap they have enormous capacity require minimal maintenance.

We have them built in a Partner factory, yes in China.

Here is an example. 60,000mah, 24S, yes (24 cell) 88.8V. A cool $4,699USD for our larger military drones.
https://www.austarsaviation.com/uav-drone-battery_1313.html

bjr981s Posted at 7-11 22:09
100% correct.

Gee.. Thanks..

After 30 years of using them, you learn a thing or two...

However, you didn't answer my question in my previous reply to you...

Burt37 Posted at 7-11 23:43
Gee.. Thanks..

After 30 years of using them, you learn a thing or two...

Sorry which one I thought I answered them in order?

Did I miss answering one?

bjr981s Posted at 7-11 23:50
Sorry which one I thought I answered them in order?

Did I miss answering one?

Oops I did them in reverse order, sorry.

izzikio_rage Posted at 7-11 09:12
So never charge to 100% never drain below 50% what are we supposed to fly with?

Noted on the broader advise if not flying with bulging battries and caring a lot for the battries

You can charge them at 100% as long as you use it and not put it away with 100% charge...

And you can go below 50%. It is just that, the more often you go below the 3.7 Volts the less the battery will last.. In DJI term you can fly from 100% to 60% and that should give you a decent amount of time. Also considering the way a Lipo battery discharge, you get the best constant power output as well if staying above the 50%

bjr981s Posted at 7-11 23:51
Oops I did them in reverse order, sorry.

No need to apologise... This forum software is ......

bjr981s Posted at 7-11 23:28
Here is a link that explains the technology reasonably well.

https://www.maketecheasier.com/solid-state-batteries/

So, if I'm reading it correctly we are going back to electrolytes and instead of using Gel it is now in a solid polymer form... Interesting, but how long before we get to the RC world?

One more thing. DJI Intelligent Flight batteries each have built-in battery management systems. No need to discharge, they do this automatically. They will not discharge too low, there is a safety margin. If they are too hot to charge, the BMS will not let them charge until they have cooled sufficiently. These are NOT the same battery systems used for RC cars and planes.