Hello.
I have 2 pieces mavic2 batteries released in August-September 2020.
only 7-8 cycles each.
everything was amazing. But at one point, perhaps after an unsuccessful firmware update via GO4 (the connection was cut off and the firmware hung by 97%) of one of the batteries (it hung in the firmware mode - the 2nd and 3rd indicators were on) and the correct renewal of the firmware via GO4 (simply continued from 97%), the battery began to conduct acting very strange. I updated the second battery without any problems, but it got the same behavior.

at the moment the problem is that the batteries cannot be turned off. Power indicator, button - work fine (it can on and off normally), but the battery remains on. If I put a off battery in the drone, it immediately starts working. Turning the battery off from the button can not turn off the drone - the battery is always on. The same thing happens if I insert an adapter on the USB - it always gives out voltage - whether the battery is off or on.

in all other situations, the batteries are fully functional, charge normally, the drone can fly with them normally.

What I tried was to flash with the help of an assistant2 and go4. firmware rollback to all possible ones (up to the 300th). the batteries were flashed and reflashed many times 100%. But this did not help in any way to solve the problem ...

I have old, swollen batteries and they work fine. They are updated to the latest 770 firmware and at the same time they turn on and off normally and work normaly ...

Can you tell me what else can I do to restore the normal power-on-off of my batteries?

I think that perhaps this happened due to the fact that in the 770th firmware you changed the battery firmware quite a lot, I ask you to release a patch or new firmware that fixes this problem.

Hi, we're deeply sorry for the trouble that this has caused. Can you please try to discharge the said battery until it goes to completely 0% and once done, try to leave it again on the charger and see if the issue persists? If yes, I'm afraid that we need to send the said battery in for proper diagnostics. Thank you for your understanding and support!

DJI Paladin Posted at 5-31 19:33
Hi, we're deeply sorry for the trouble that this has caused. Can you please try to discharge the said battery until it goes to completely 0% and once done, try to leave it again on the charger and see if the issue persists? If yes, I'm afraid that we need to send the said battery in for proper diagnostics. Thank you for your understanding and support!

after discharging to zero, one of my two faulty batteries simply stopped charging at all. "thank you" for the advice ...

b2rdetor Posted at 6-3 09:39
after discharging to zero, one of my two faulty batteries simply stopped charging at all. "thank you" for the advice ...

Hi, we do apologize for the trouble. Kindly please leave the battery on the charger for approximately 2-3 hours and check if the issue persists. If yes, I'm afraid that we need to send the battery for proper diagnostics. The warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. To check the warranty period parts of your drone, you may click this link: https://www.dji.com/service/policy. Thank you for your kind and understanding.

I left it on charge for 2 days and it did not help in any way. The battery is dead. I am sure that it controller just blocked ... I have 5 batteries for the mavic2 3 of them are swollen (although they still work properly, and they are normally updated to the 770th firmware) and two almost new ones that do not work correctly (one of them is now completely inoperative) ...
I have never seen such a disgusting quality. It is unlikely that I will buy any dji product in the future. It is nonsense to send batteries to you, because the cost of shipping is equal to the cost of a new battery. it's better to disassemble them and put NORMAL lithium batteries in there... extremely negative experience with your products ...

b2rdetor Posted at 6-4 08:32
I left it on charge for 2 days and it did not help in any way. The battery is dead. I am sure that it controller just blocked ... I have 5 batteries for the mavic2 3 of them are swollen (although they still work properly, and they are normally updated to the 770th firmware) and two almost new ones that do not work correctly (one of them is now completely inoperative) ...
I have never seen such a disgusting quality. It is unlikely that I will buy any dji product in the future. It is nonsense to send batteries to you, because the cost of shipping is equal to the cost of a new battery. it's better to disassemble them and put NORMAL lithium batteries in there... extremely negative experience with your products ...

If you send the batteries to DJI they might be able to determine the problem.  This could benefit all drone pilots.  I hope you reconsider your decision to not send the batteries for diagnosis.

Spazoo Posted at 6-4 15:51
If you send the batteries to DJI they might be able to determine the problem.  This could benefit all drone pilots.  I hope you reconsider your decision to not send the batteries for diagnosis.

if DJI were worried about their customers, they would release normal batteries and FREE SHIPPING of bad batteries and other faulty parts.
For the shipping cost, I can buy 3 sets of quality lithium batteries and repack my swollen original batteries with them. so no - sending your faulty batteries PAYMENT DOES NOT MAKE ANY SENSE.

Spazoo Posted at 6-4 15:51
If you send the batteries to DJI they might be able to determine the problem.  This could benefit all drone pilots.  I hope you reconsider your decision to not send the batteries for diagnosis.

if you are interested, then I figured out the problem. this is a hardware problem. To diagnose it, I had to disassemble both of my malfunctioning batteries. The upper arm of the mosfets (2 pcs) turned out to be faulty. they are both pierced (marked in blue in the figure). And there are quite a few such cases. What is the reason that 100A (PSMN1R5-30YLC) mosfets are not clear. Replacing them is a very cheap event and clearly not worth sending your batteries to dji

fansfb8375c3 Posted at 7-11 04:05
[view_image]if you are interested, then I figured out the problem. this is a hardware problem. To diagnose it, I had to disassemble both of my malfunctioning batteries. The upper arm of the mosfets (2 pcs) turned out to be faulty. they are both pierced (marked in blue in the figure). And there are quite a few such cases. What is the reason that 100A (PSMN1R5-30YLC) mosfets are not clear. Replacing them is a very cheap event and clearly not worth sending your batteries to dji

That is an interesting find, and the type of thing DJI should be made aware.

I’m not wearing my glasses at the moment, but that looks like a solder bridge you have highlighted with red pen.

Spazoo Posted at 7-11 05:55
That is an interesting find, and the type of thing DJI should be made aware.

I’m not wearing my glasses at the moment, but that looks like a solder bridge you have highlighted with red pen.

no, it's not solder. this is the remnants of the protective varnish after the probes of the multimeter)
the board itself is made and protected with varnish very well - no complaints about quality, but nevertheless the upper arm mosfets failed for no reason.

as far as I'm aware of the dji is experiencing a massive problem with the marriage of mosfets on batteries on mavic air 2

and it looks like a similar problem exists on 2020 and all new batteries for mavic 2

it is definitely marriage and the fault is completely on the DJI

DJI Paladin Posted at 2021-5-31 19:33
Hi, we're deeply sorry for the trouble that this has caused. Can you please try to discharge the said battery until it goes to completely 0% and once done, try to leave it again on the charger and see if the issue persists? If yes, I'm afraid that we need to send the said battery in for proper diagnostics. Thank you for your understanding and support!

Do not do this unless you are 100% sure. Several DJI battery models die out when they get completely depleted.

rogiervdheide Posted at 1-25 08:30
Do not do this. Most DJI batteries die out when they get completely depleted.

Hello, there. Thank you for your input. If the Intelligent Flight Battery has been completely depleted for a long time, this may cause a battery cell and the battery may not charge afterward. However, this recommendation for discharging is part of the troubleshooting steps. Furthermore, it's recommended to fully charge and discharge the battery at least once every 3 months to maintain battery health. I hope this information helps.

DJI Gamora Posted at 1-27 02:42
Hello, there. Thank you for your input. If the Intelligent Flight Battery has been completely depleted for a long time, this may cause a battery cell and the battery may not charge afterward. However, this recommendation for discharging is part of the troubleshooting steps. Furthermore, it's recommended to fully charge and discharge the battery at least once every 3 months to maintain battery health. I hope this information helps.

Sure DJI Gamora, thanks for the additional remarks to my comment. I have made a slight edit to reflect what I elaborate on below.

When advising DJI users to deplete their batteries, it is important to state that not all DJI batteries benefit from this, and some models will die.
For instance, we have seen depleted TB55 batteries that cannot be brought back to life at all. They are not hibernating, they are dead.
We have also seen many Ronin M/MX 1580mAh batteries that were depleted and do not come back to life.

These batteries might recover when we clear the permanent failure flag in the TI battery management chip.
This is not something that normal drone users can do or have the gear for.

We have also seen TB47 batteries that only came back to life after disconnecting the internal balance wire.

So the trade off is here: should we recommend people to follow a battery recovery procedure even though we know that some of the DJI battery models will die as a result of it? Should we not recommend the procedure because people will not always understand that the procedure does not apply to the specific DJI batteries they have?

I opt for the second: since the procedure does not apply to all batteries, some models will even die permanently as a result of it, and people easily try out things in their attempt to fix the problem themselves, I would not recommend this procedure unless we are explicit about the battery models it applies to.

Thanks
Rogier