Mavic Air's battery went from 91% to 0% suddenly.
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TC2
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On Feb. 02,2020, when in flight with a Mavic Air, the battery went from 91% to 0% suddenly, causing it to land in an emergency.
  
I fully charged (100%) all my 4 batteries, the day before the flight.
  
On the first flight, on the way up, I took two photos, put it in Sport mode, and moved on. Suddenly the battery went from 91% to 0%, causing me inconvenience. Luckily the drone did not descend on a busy highway, where an accident could have occurred. At the time I had not seen that the problem had a battery issue. I didn't fly there anymore, thinking that place was some restriction, but it wasn't. Only after arriving home, when checking the flight history/log,I see that the problem had been with the battery.
  
The day before yesterday, a colleague of mine, also with a Mavic Air, after having previously charged the battery completely (100%), while flying, the same problem happened, his battery suddenly went from 83% to 0%. As he was on a boat, over a lake, he ended  losing the drone.
  
That’s very sad. L
  
What's going on. I saw that there are other reports in this forum, however, those that I saw, report that they started the flight with the battery without being at 100%, which was not my case, nor that of my colleague.
  
I completely lost confidence in the drone, as I think the problem could occur with any of my other three batteries.
  
  What's going on,  Dji guys ???
2020-2-27
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DJI Paladin
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Hi. I am sorry for the trouble this has caused. With regards to this concern. Kindly please provide me the serial number of the affected battery by PM. Thank you.
2020-2-27
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Labroides
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Post recorded flight data to find out what happened.
2020-2-27
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The Otter
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Just a reminder that batteries require constant care. The user manual for the batteries (that I am sure not one reads sadly) will tell you what to do to take care of them and help improve their life time. The Battery Storage part is particularly important.

Here is the link if you can't find the piece of paper: https://dl.djicdn.com/downloads/Mavic%20Air/Mavic%20Air%20Intelligent%20Flight%20Battery%20Safety%20Guidelines%20v1.0.pdf

It's from https://www.dji.com/nz/mavic-air/info#downloads.

Good luck
2020-2-27
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TC2
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Guys, thanks for answering.
Regarding your arguments:
-The battery was manufactured in September 2018 and is no longer under warranty.
-It always loaded and unloaded normally during flights. On my flights, I always lower the drone when receiving the signal for landing or returning. I usually leave the minimum value for return notice (RTH) at 25%.
-As for reading the manual ... Yes, I did, and I keep my batteries with the informed care.
2020-2-28
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AlansDronePics
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I see you are in Brazil. You mentioned you were in sports mode but never mentioned if you had been running at full power for long.
My comment is only intended to be helpful to you because you are seeking reasons for the problem. This MAY be a consideration...
If the day was hot and sunny, plus the heat generated in the battery after sustained full power, might have caused a fault in a cell. The battery chemistry is susceptible to damage and degradation at high temperatures.
I recently had a Mavic Pro battery with about 35 charges fail to complete a firmware update. The symptom was the middle 2 LEDs staying lit and no charging was possible. I mention this in case anyone has this symptom. The battery was ruined, so I took it apart. During experimentation, it was apparent that in a 3 or more cell stack, the middle cells cannot ventilate and dissipate heat like the outer cells. That all makes logical sense for a compact battery. The temperature sensor is glued to the outer edge of a cell, so any overheating of the core is not detected. Only the cooler part is measured by the software. I conclude that the designer sets the measured temperature a lot lower than the core is likely to reach and in a hot climate, there might be enough heat built up to predict battery failure. The drone would attempt to land immediately.
Perhaps the battery temp from the sun on the case triggered the landing?
From personal experience, on a hot day in the UK, the battery case soon gets very warm. Goodness knows how hot the battery would get on a hot day in Brazil after using sports mode for a few minutes.

Here are some links about hot LiPos so you can check things out yourself.
https://wp.josh.com/2015/12/26/b ... es-on-lipo-voltage/
https://www.sciencedirect.com/sc ... i/S1002007118307536
http://www.tawaki-battery.com/how-temperature-affects-batteries/
2020-2-28
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TC2
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Thanks for trying to help, butI think that is not the case.
Before using the drone, it was in the bag and in the air-conditioned car. I just stopped the car, prepared the drone for the flight, climbed up, hovered a bit, took two pictures, put it in Sport mode, and in level flight, put the R / C crank fully forward. A few seconds later, the problem occurred.
After this, I charged and discharged the battery 3 times. Two with the drone stopped. And one last time with the drone in flight. The battery that failed, charged and discharged normally. The flight test, I simulated several options, with and without Sport mode, and nothing happened.
The interesting thing is that it also happened with a friend's Mavic Air. At night, around 8:30 pm, he climbed the drone from a sailboat. When he reached a certain height, he left the drone hovering, while the sailboat followed. He put the drone to follow the boat to start filming it. It was not in Sport mode. Suddenly the battery went from 83% to 0%, without my friend being able to do anything. The drone hit the water, submerged a little, went up and then dived  ... Lost the drone ...   
That is. It happened with two different devices, in different locations and conditions. Both he and I take care of the batteries as stated in the manual. I know his story because he told me. I don't usually fly with him. We make our flights independent, having no connection of place and way of flying.
Very ... But very strange ...!

That is. It happened with two different devices, in different locations and conditions. Both he and I take care of the batteries as stated in the manual. I know his story because he told me. I don't usually fly with him. We make our flights independent, having no connection of place and way of flying.
Very ... But very strange ...!
        
2020-2-28
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Labroides
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TC2 Posted at 2-28 16:17
Thanks for trying to help, butI think that is not the case.
Before using the drone, it was in the bag and in the air-conditioned car. I just stopped the car, prepared the drone for the flight, climbed up, hovered a bit, took two pictures, put it in Sport mode, and in level flight, put the R / C crank fully forward. A few seconds later, the problem occurred.
After this, I charged and discharged the battery 3 times. Two with the drone stopped. And one last time with the drone in flight. The battery that failed, charged and discharged normally. The flight test, I simulated several options, with and without Sport mode, and nothing happened.

All the words you type don't mean a thing without the data to show exactly what happened.
2020-2-28
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AlansDronePics
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TC2 Posted at 2-28 16:17
Thanks for trying to help, butI think that is not the case.
Before using the drone, it was in the bag and in the air-conditioned car. I just stopped the car, prepared the drone for the flight, climbed up, hovered a bit, took two pictures, put it in Sport mode, and in level flight, put the R / C crank fully forward. A few seconds later, the problem occurred.
After this, I charged and discharged the battery 3 times. Two with the drone stopped. And one last time with the drone in flight. The battery that failed, charged and discharged normally. The flight test, I simulated several options, with and without Sport mode, and nothing happened.

I see some other reports of a similar issue, so it is possible there is a firmware issue with the drone. If it is, then it will be a risky time flying. A couple of years ago, Mavic PROs had a spate of erratic behaviour and that passed after some firmware updates.
Good luck,
2020-2-28
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JJB*
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Best to upload those 2 flightlogs, battery voltage values will explain what happend.
No logs = only guessing and speculations.

Not good for DJI and not good for forum members.

cheers
JJB
2020-2-29
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LordErec
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I had this exact same problem with my Mavic Air when I first got it. One of the batteries was defective and spontaneously died in flight. Thankfully the drone was hovering just a few feet off the ground at the time, so no damage, but it took several weeks for DJI to replace the battery (thankfully they accepted it as defective).

Not long afterwards there was a firmware update for the batteries, not sure if it was related.
2020-2-29
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TC2
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I didn't know how to see the log. After consulting the internet, I found a website to "translate" the log. I was able to upload and see what happened. In 32.7s there was a forced landing. The log is available at this link >> https://www.phantomhelp.com/logviewer/I7AZF0ILDI4PDP2CZFR4
2020-3-2
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TC2
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Correcting ...  37.2s and not 32.7s
2020-3-2
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JJB*
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TC2 Posted at 3-2 07:36
I didn't know how to see the log. After consulting the internet, I found a website to "translate" the log. I was able to upload and see what happened. In 32.7s there was a forced landing. The log is available at this link >> https://www.phantomhelp.com/logviewer/I7AZF0ILDI4PDP2CZFR4

Hi TC2,

At 27.s a message in the log "BattTempVoltageLow" (not on the screen), followed by a serious drop in cell 3.

Once a cell drops below a certain low value the SW will show 0% for battery level.
And ofcourse value at or below critical warning will initiate a landing.

The start values at 94% are normal, only the max deviation is mayby a sign of future problems. But have seen more deviations like this at a start wich did not result is a cell 'failure'.

So my 2cents : a bad battery (cell#3) and if the warning about temperature is correct that this didn`t help the battery performance.


cheers
JJB
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2020-3-2
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TC2
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Hi JJB *, thanks to you and the others who volunteered to help me.
What makes me sad and afraid is that now flights with my Mavic Air and my son's Spark have become tense, not knowing if such a problem will occur when the drone is very far and / or over some mass of water. I didn't have this problem before, I fully trusted the drone. Before, this battery had no problem, at least easily detectable, and in less than a month there were two know events near me, mine and my colleague's, who lost the drone ...    And, interestingly, is that after the event, I already made 02 flights of hovered tests and two with it stopped, and the battery decreased normally, I don't know if in a more detailed analysis, by the log, there were problematic variations in the cells. Anyway, here is the my record. Thanks.
2020-3-3
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TC2 Posted at 3-2 07:36
I didn't know how to see the log. After consulting the internet, I found a website to "translate" the log. I was able to upload and see what happened. In 32.7s there was a forced landing. The log is available at this link >> https://www.phantomhelp.com/logviewer/I7AZF0ILDI4PDP2CZFR4
Your drone is fine but that battery is suspect.

Ignore the 94% and 84% you see in the Phantomhelp report.
Those numbers are not being reported correctly.
Instead look at the cell voltages which collapsed rapidly after launching.
The cells should have been above 4 volts and slowly decreased but within a short time cell 3 was down at critical low voltage level of 3.3 volts.
When you engaged Sport Mode at 33 seconds, all cells were down at critical low voltage.
The battery is sick or was not freshly charged properly.

Charge it again and power up the drone with it.
Then go the battery display in the Go app and see what the cell voltages are like.
If they are over 4 volts, you could launch and fly low and slow over soft grass while watching the cell voltages in the app.
If the voltages drop quickly, that's confirmation that battery is sick.
2020-3-3
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Ulysses
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I find funny guys here always trying to blame the user or another external factor for this battery problem with Mavic Air. It is happening all over with Air owners. I had all 3 batteries of my fly more combo with this sudden drop midflight. The third one happened last week. Its happening all over and how come you guys dont see it and connect the dots? It surely is a design flaw but DJI remains silent about acknowledging that. Now Im always afraid to fly but sometimes I need to because its a job. I will reply this same message to all other 2 topics I read today. There were 2 from me from the first 2 batteries and a lot more from other users. DJI needs to do something as they sold us a product promising it was safe. And it would be if there wasnt this battery problem happening all of a sudden, no sign, no message, no physical damage to the battery.
2020-3-5
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TC2
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I fully agree with you Ulysses. I left the battery that they said was in trouble, the # 0K4F94A3501Q1 aside. Despite having tested it while still and in flight, I was no longer safe using it. I bought a new battery to keep a set of three. He was always using this new one on the first flights, and the older ones on subsequent flights. Well, on 03/13/2020, in the late afternoon, using one of the old batteries, the problem happened again, now with a battery other than # 0K4F94A3501Q1 (I don't know how to see her number through the log that have ). This time the Mavic Air was over the sea, taking a 360o panoramic photo, the battery went from 33% to Zero, causing the drone to make a forced landing in the sea. I lost the Drone! How angry at Dji. The device has several safety devices and there is none that warns the user that a certain battery has a problem! Inadmissible! My drone is no longer under warranty, and I think the battery that was a problem came with it. I don't know if it was one that Dji had made a replacement, but even so, I think that it is entirely Dji's fault. They cannot be exempt from this problem, which seems to be recurring worldwide! It is as if the battery of a certain type of car is causing problems and these cars suffer accidents with total loss. Dji has to bear these losses. Dji should be doing a general recall of these batteries !!!!
2020-3-15
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TC2
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JJB* Posted at 3-2 07:59
Hi TC2,

At 27.s a message in the log "BattTempVoltageLow" (not on the screen), followed by a serious drop in cell 3.

Please JJB *, could you do the "translation" as you did on the problem that had previously occurred? I don't know the battery number. I wonder. I'm going to look for DJI after replacing a new drone. If it doesn't succeed, I'll spend my money on justice behind Dji's recognition and also for the replacement of the drone! I'm angry!!   The fateful flight log is on this link ...  >>>  https://www.phantomhelp.com/logviewer/O7WDK04ZJIQ3JPOQ4FDH/
2020-3-15
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TC2
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Please, before posting on this topic, remember that I always took good care of my batteries. The day before, I looked at all of them. I loaded them all at 100%. I disconnected them from the charger, did the charging procedure again, and none of them loaded again, that is. They were all 100%. This the day before use, as he would leave home at dawn and would not be able to load them on the same day of the flight. THE BATTERIES WERE ALL CHARGED 100%!
2020-3-15
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TC2 Posted at 3-15 14:20
Please JJB *, could you do the "translation" as you did on the problem that had previously occurred? I don't know the battery number. I wonder. I'm going to look for DJI after replacing a new drone. If it doesn't succeed, I'll spend my money on justice behind Dji's recognition and also for the replacement of the drone! I'm angry!!   The fateful flight log is on this link ...  >>>  https://www.phantomhelp.com/logviewer/O7WDK04ZJIQ3JPOQ4FDH/

Hi TC2,

No problem, see the chart.

cheers
JB
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2020-3-16
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TC2
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Thank You, JJB*!!

2020-3-16
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TC2 Posted at 3-15 14:14
I fully agree with you Ulysses. I left the battery that they said was in trouble, the # 0K4F94A3501Q1 aside. Despite having tested it while still and in flight, I was no longer safe using it. I bought a new battery to keep a set of three. He was always using this new one on the first flights, and the older ones on subsequent flights. Well, on 03/13/2020, in the late afternoon, using one of the old batteries, the problem happened again, now with a battery other than # 0K4F94A3501Q1 (I don't know how to see her number through the log that have ). This time the Mavic Air was over the sea, taking a 360o panoramic photo, the battery went from 33% to Zero, causing the drone to make a forced landing in the sea. I lost the Drone! How angry at Dji. The device has several safety devices and there is none that warns the user that a certain battery has a problem! Inadmissible! My drone is no longer under warranty, and I think the battery that was a problem came with it. I don't know if it was one that Dji had made a replacement, but even so, I think that it is entirely Dji's fault. They cannot be exempt from this problem, which seems to be recurring worldwide! It is as if the battery of a certain type of car is causing problems and these cars suffer accidents with total loss. Dji has to bear these losses. Dji should be doing a general recall of these batteries !!!!

The cell voltage drop is very odd. To me, it looks like either bad PCB or faulty firmware. I leaning toward firmware because of the 02/02 flight. At 11.8 - 11.9 seconds voltage drops .1V for each cell, at 28 - 28.1 seconds, the voltage of all cells jumps .1 V then 31 - 31.1 seconds they jump .2 - .3 V.  Then at 32 - 32.1seconds they all drop .2 - .35V, worse still, at 33 - 33.1 seconds, C1 drops 0.134V C2 drops 1.156V(!!!), and C3 drops 0.3. This happened again at 34-34.1 seconds. Why on earth would this happen, except firmware not measuring Voltage correctly of a partial short in the PCB?
2020-3-19
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KN4LGM
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TC2 Posted at 3-15 14:20
Please JJB *, could you do the "translation" as you did on the problem that had previously occurred? I don't know the battery number. I wonder. I'm going to look for DJI after replacing a new drone. If it doesn't succeed, I'll spend my money on justice behind Dji's recognition and also for the replacement of the drone! I'm angry!!   The fateful flight log is on this link ...  >>>  https://www.phantomhelp.com/logviewer/O7WDK04ZJIQ3JPOQ4FDH/

Now for the 03/13 flight. Voltage drop at 2.9 - 3 seconds, C1 0.513V, C2 0.444V, and C3 0.31V. At 4 - 4.1 second cells gained, C1  0.111V, C2 0.113V, and C3 0.1V. Slight drop at 7 seconds(.3V).  At 8 - 8.1 second cells gained, C1 0.153V, C2 0.136V, and C3 0.1V. Slight drop at 9 - 9.1(0.1V). Drop at 10 - 10.1, gain at 12 - 12.2, drop at 13 -13.1, drop at 14 -14.1, then start gaining and dropping 0.01V at 15.1 And never stops. Cell 1 goes below 3.3V at 8 min 43.7 seconds, and starts dropping faster and faster till 9 min 37.4 with a voltage of 2.047! I suggest to all other Mavic Air users that you should enable the Low Battery Voltage warning in the DJIGo app.

2020-3-19
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TC2
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KN4LGM Posted at 3-19 19:17
Now for the 03/13 flight. Voltage drop at 2.9 - 3 seconds, C1 0.513V, C2 0.444V, and C3 0.31V. At 4 - 4.1 second cells gained, C1  0.111V, C2 0.113V, and C3 0.1V. Slight drop at 7 seconds(.3V).  At 8 - 8.1 second cells gained, C1 0.153V, C2 0.136V, and C3 0.1V. Slight drop at 9 - 9.1(0.1V). Drop at 10 - 10.1, gain at 12 - 12.2, drop at 13 -13.1, drop at 14 -14.1, then start gaining and dropping 0.01V at 15.1 And never stops. Cell 1 goes below 3.3V at 8 min 43.7 seconds, and starts dropping faster and faster till 9 min 37.4 with a voltage of 2.047! I suggest to all other Mavic Air users that you should enable the Low Battery Voltage warning in the DJIGo app.

KN4LGM, enabling the low voltage warning, would I be alerted before the flight?  In fact, I don't even know how to do this. and now, with the loss of the Mavic Air, I will not be able to try.
2020-3-20
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TC2
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I think the problem is chronic for Mavic Air. I contacted Dji and they, since the guarantee ended in December 2019, offers only a discount for the purchase of a new one. This is not correct! I did all the correct procedures, I had a similar problem previously with a battery that was not the one used when the drone was lost at sea. A close colleague also lost his Mavic Air for the same reason. Dji must replace a new drone for me and for all users who have lost their drones for this reason. It seems that after a year, these batteries are no longer useful! There is no early warning of the problem, leaving users with the problem at hand and the uncertainty of flying with their drones. This is a problem worthy of full recall of these types of batteries!
2020-3-20
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slup
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As I see it it's mainly 2 thing's that keep our drones airborne ... props & batteries, if any of them fail the aircraft goes down as a rock.

When it comes to the props I think all understand that nicks, bends, hits & general abuse risk the coming flights ... it's pretty common that pilots add an visual check both of the props them selves but also regarding the attachments.

But batteries ... what about "nicks, bends, hits & general abuse" on them?

Yeah ... can be hard to check off visually, some leave them in the charger so they always are 100%, others just store them full to be ready for the next flight opportunity. Some fly them really low then leave them waiting weeks for the next flight session. Or perhaps store them in a hot car, maybe charge them directly after a flight still hot? All this is major battery abuse not seen outside.

It's so many ways people abuse their batteries ... none of the ways will show any visual damage. If they take charge to 100% all seems fine ... or?

Aside the most obvious visual damage of a battery ... swelling, it's hard to judge when it's time to take a battery of flight duty & just use it for ground duty like settings & offloading pics & movies.

But it exist one way ... this way consists of monitoring the battery performance & cell deviation over time ... the trends. The trend is important as all batteries degrade over time & usage ... until the point where some of the cells in the battery suddenly fails & leaves our drone mid air without enough voltage to sustain continues flight.

Airdata.com have this with battery trend followup's pretty good layed out ... of all flight logs you have there you can read off the performance & cell deviations over time, you can monitor the degradation & take it out in time before something happens. (This functionality is unfortunately only included in their payed subscriptions ... but I see it as an insurance well worth the cost)

This is a couple of graphs from there, based on all my hundreds of flights ... one of my best & one of my worst batteries.

The best (from 18 July 2019):





And from the latest flight with it ...



Then the worst (from 15 Jan 2019):





And from the latest flight with it ...



And then if we compere the above individual flight graphs with the OP's battery below (no trend, only what happened during this flight)
This didn't happen suddenly ... this is the final stage of a longer period of degradation, if this battery had been followed it should have been grounded much earlier.

A LiPo cell have a max voltage of 4,2V & below 2,7-3,0V it starts to get permanent damage ... 50% battery is approx 3,7V
So this battery is now permanently & severely damaged as cell 3 were discharged well below the minimum cell voltage ... it fell all the way down to just below 2,3v. Dji Drones will start autoland when the cell voltage goes below 3,0V.

This whole event haven't so much to do with DJI's software ... this battery were totally messed up already several flights before this, in a sense a time bomb ... very much alike a brutally abused prop with cracks & large chunks broken off.


2020-3-20
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bjr981s
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Do you use the standard battery charger or an alternate fast charger?
2020-3-21
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djiuser_vv2amfATHrn6
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Hello I Have The same issues With My Dji Mavic Air Fly More Combo I have Fully Charge The 3 Battrys When I Was Flying It Shows 100% To 0 Emergency landing at the suparmarket near to my house i have the fear of my life...I have The Same Problem With All The 3 Batrys Tell Me What I can Do thx..
2020-3-22
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bjr981s Posted at 3-21 05:26
Do you use the standard battery charger or an alternate fast charger?

Standard. I always used the charger that comes with the fly more combo. I never used a charger without what Dji provided, so I understand it to be a chronic problem with this battery model, because in two of them (mines) it failed and I am aware of others, such as that of my colleague who also lost the drone when the battery suddenly discharged and the drone fell into a lake
2020-3-23
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djiuser_vv2amfATHrn6 Posted at 3-22 00:48
Hello I Have The same issues With My Dji Mavic Air Fly More Combo I have Fully Charge The 3 Battrys When I Was Flying It Shows 100% To 0 Emergency landing at the suparmarket near to my house i have the fear of my life...I have The Same Problem With All The 3 Batrys Tell Me What I can Do thx..

Another similar problem to our knowledge! I'm angry full level! We are totally insecure to proceed with the flight. And be careful! If by chance you lose it, Dji will not replace it if the warranty period has passed. In my case, the 02 defective batteries were more than 01 years old and soon after the expiration of the warranty came to give sudden defects. That of my colleague, who also lost his Mavic Air, the battery that had a problem was also more than a year old. Dji is totally at fault for the loss of my device, as well as that of everyone who will lose their Mavics Air, as the problem happens suddenly, without any warning to the owner. I  think it would be a cause for recall, as it is putting people's lives at risk. In the first incident with my Mavic Air, it landed emergency right next to a busy highway. I'm glad you didn't hit a car. Having discarded the battery that had failed, I thought my problem was solved. My mistake, I ended up losing the Mavic Air, when it came to fall offshore due to this problem.
2020-3-23
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slup Posted at 3-20 16:12
As I see it it's mainly 2 thing's that keep our drones airborne ... props & batteries, if any of them fail the aircraft goes down as a rock.

When it comes to the props I think all understand that nicks, bends, hits & general abuse risk the coming flights ... it's pretty common that pilots add an visual check both of the props them selves but also regarding the attachments.

I appreciate your contribution/explanation and it may even be worth signing up on this site to check the batteries, but I think that not everyone will have enough knowledge to 'decipher' the graphics. Dji should have provided in its DjiGo4 application some way that the 'layman' would be notified in advance. Thanks for the contribution.
2020-3-23
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slup
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TC2 Posted at 3-23 05:43
I appreciate your contribution/explanation and it may even be worth signing up on this site to check the batteries, but I think that not everyone will have enough knowledge to 'decipher' the graphics. Dji should have provided in its DjiGo4 application some way that the 'layman' would be notified in advance. Thanks for the contribution.

"... may even be worth signing up on this site to check the batteries, but I think that not everyone will have enough knowledge to 'decipher' the graphics."

This isn't rocket science, Airdata.com explain in relation to those trend graphs pretty well what's OK & when to proceed with caution & start to monitor closely.

As this with the battery degradation happens over time it's not so much worth to look at how a battery behaved during a single flight, the strain for a battery can vary largely depending on for instance air temp, how hard you fly the drone & wind conditions. So having these trends in the GO4 app directly will be difficult.

GO4 have warnings when this will happen though, the culprit is only that it will show just before it happens ... you can have the voltage for the lowest cell showing beside the battery percentage, only iOS though, not Android ... there you will have to go into battery advanced settings to see. Then you will get a warning message in the app regarding low voltage, which you did just seconds into your flight ... but easy to miss. And the drone actually does the only thing it can instead of free falling ... it force lands while it's some voltage left in the battery... that's kind of something from the GO4 app also.

All you can do regarding this is to educate yourself, handle the batteries according to the recommendations & monitor the battery performance trends over time.

If your expectation is that this should only be a simple matter of paying for the battery then forget it then it will ground your drone again sooner or later ... and this isn't unique for the MA, have seen this happen on all drone models & brands with LiPo batteries. The only common factor I have seen so far is that the owners always were taken by surprise, didn't have a clue about proper storage procedures, didn't have the slightest interest to learn & preferred to blame somebody else.

Head over to Airdata & sign up, and start to monitor ... for your own & your drones sake.
2020-3-23
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TC2
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slup Posted at 3-23 06:24
"... may even be worth signing up on this site to check the batteries, but I think that not everyone will have enough knowledge to 'decipher' the graphics."

This isn't rocket science, Airdata.com explain in relation to those trend graphs pretty well what's OK & when to proceed with caution & start to monitor closely.

I appreciate your comment and your tips and I will, after solving this problem, and get a new device, use the app you recommended to monitor the batteries. As for taking care of the batteries, recommended in the Dji manuals, I went. I already explained above. As for the problem of monitoring the battery cells using programs not provided by DJI, I didn't do that, because I had nowhere in the manual to do this procedure. Also in the DjiGo4 app, during the flight, it is impractical for you to be taking pictures and checking the condition of the cells. I'm not the type to blame companies without reason. However, being right, I go to the last consequences. And in this case, I have.
2020-3-24
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slup
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TC2 Posted at 3-24 06:57
I appreciate your comment and your tips and I will, after solving this problem, and get a new device, use the app you recommended to monitor the batteries. As for taking care of the batteries, recommended in the Dji manuals, I went. I already explained above. As for the problem of monitoring the battery cells using programs not provided by DJI, I didn't do that, because I had nowhere in the manual to do this procedure. Also in the DjiGo4 app, during the flight, it is impractical for you to be taking pictures and checking the condition of the cells. I'm not the type to blame companies without reason. However, being right, I go to the last consequences. And in this case, I have.

Please note that even though Airdata have an app... I mean their web site Airdata.com ... also remember that you need a payed subscription there to get access to the battery trend evaluation pages.

But as I said ... eventually this will happen to all batteries as they will not last forever, so it's a cheap insurance for your drone, for you to get the possibility to take out a battery before it takes it self out mid air.

Once you have set up a Airdata account you can set it to fetch the logs automatically ... if you have synced your flights with the DJI servers from the GO4 app. Easy & convenient ...

Can also add a bit about proper battery care as DJI is to vague regarding this ...

1. Keeping the battery at 100% isn't good for it ... do what you can to minimize the time that they are at that level (the default 10 days auto discharge down to 60-65% is way to long ... & if you check the level by pushing the button you reset the counter & the 10 day counter will restart). If a battery that is  above storage % level haven't been used in a couple days, use the usb adapter from the Fly More Kit to charge something else (your phone) in order to bring it down to storage % (see below ...)

2. Heat kills them ... don't store above room temperature & absolutely not in a car during summer, 5 hours in a burning hot car & the battery have sustained serious damage.

3. Let them cool down to room temperature before recharging them.

4. Don't fly with a battery colder then 15C degrees, keep them warm in colder weather, have them in a pocket close to your body.

5. Store the batteries between 40-60% ... a good thumb rule is to take them of the charger as soon as the third led start to blink, then they are just over 50%. But anything between 1 solid + 1 blinking up to 2 solid + 1 blinking is good enough.

6. Don't drain them to low, make sure they don't go under 10% ... once in a while, so be it. Try to not have them lower then 20% ... if you aim for that you usually don't end up below 10%.

7. If stored for a long time, cycle them at least once each third month ... then back to storage %.

Think that's all ...

  




2020-3-24
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JonnyHammer
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This "critically Low Voltage Warning" message should be given much sooner. It's absolutely nonsense get this message when it's already an emergency landing situation.... I can't figure out why DJI developers decided to put this message only in the last moment, unbelievable.

The correct way to avoid this is to show cell deviation on the app main screen, for example, once it deviates 20% the first warning is shown, 40% the second and there it goes....it's so simple, then we can fly the drone back safely before it's critical.

But somehow DJI decided there is no need for these previous warnings, only one when you about to do an emergency landing. Depending where the drone is flying (above water, busy road, properties etc) the operator will have nothing to do to save it.

This needs to change immediately or many people will lose their drones. I have to say that this problem shook my confidence on DJI, I'm always thinking that this failure can happens and have to check the battery screen all the time, ruining the fun of flying.
2020-3-24
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slup
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JonnyHammer Posted at 3-24 11:11
So many people with the same problem....clearly mavic air batteries are not reliable. Some people say that sports mode can damage the battery, so why is there a sport mode in the first place?

This "critically Low Voltage Warning" message should be given much sooner. It's absolutely nonsense get this message when it's already an emergency landing situation.... I can't figure out why DJI developers decided to put this message only in the last moment, unbelievable.

"-...DJI needs to do these changes immediately or many people will lose their drones..."

I already told you in your own thread about your cell failure that a battery needs constant care & observation ... ALL LiPo batteries will come to a cell failure eventually! If you only fly on without doing nothing this will always come as a surprise, even for GO4.

If you prefer to put all trust in DJI & blame others instead of educate yourself & take your responsibility it's up to you ... but have already explained all this to you earlier ... have you started to follow your batteries at Airdata.com yet or do you prefer to just rant about the obvious fact that batteries will fail eventually?

You will never know for sure when a cell in a battery will fail more then just before it happens ... you need to see the trends from several flights to see the degradation & predict/decide end of flight duty for a battery.

If you look at your own event & the battery data from your 2 year old battery with unknown care history, from that single flight ... when was it clear that a cell should fail?

2020-3-24
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JonnyHammer
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slup Posted at 3-24 12:38
"-...DJI needs to do these changes immediately or many people will lose their drones..."

I already told you in your own thread about your cell failure that a battery needs constant care & observation ... ALL LiPo batteries will come to a cell failure eventually! If you only fly on without doing nothing this will always come as a surprise, even for GO4.

You don't seem to understand the main point here: The Warning should be given earlier and multiple times, that's it, make the warning pop-up earlier when the cell deviation is not critical, RTH and save your drone.

All of what I'm saying here lately points to the direction of the warning, so I'll say again: There is absolutely no reason to give a "warning" when the situation is critical and there is no chance to take preventive action.

I'll just ignore what you said about me not taking responsibilites or lack of education, this is personal and don't aggregate anything, I know that I take good care of my batteries.

If it has to happen anyways, fine, all I'm questioning is the timing of the "warning". It's preventable.
2020-3-24
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slup
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JonnyHammer Posted at 3-24 15:43
You don't seem to understand the main point here: The Warning should be given earlier and multiple times, that's it, make the warning pop-up earlier when the cell deviation is not critical, RTH and save your drone.

All of what I'm saying here lately points to the direction of the warning, so I'll say again: There is absolutely no reason to give a "warning" when the situation is critical and there is no chance to take preventive action.

Sorry but you severely lacks knowledge over how a LiPo battery works and behaves & you gives that away by suggesting pop-ups earlier ... when earlier?

It's perfectly normal to have minor deviations (the green bars in the Airdata chart) & even major ones (the red bars) if you JUST look at one single flight. If you want them all as warnings you will have thousands of messages in GO4 each & every flight. But no one can predict when everything becomes critical & one of the cells will give up. To foresee anything you need to look at ALL flights regarding how the batteries behaved ... judge how the trend is going and eventually decide when enough is enough & take the battery off duty.

You plain & simple can't achieve what you are suggesting by only looking at one flight ... but was worse is that you by your ingnorance keep others to believe that this should be taken care of by DJI which leads to that more pilots keep on thinking this isn't their responsibility & by that more drones keep on falling from the sky.
2020-3-25
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JonnyHammer
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slup Posted at 3-25 00:21
Sorry but you severely lacks knowledge over how a LiPo battery works and behaves & you gives that away by suggesting pop-ups earlier ... when earlier?

It's perfectly normal to have minor deviations (the green bars in the Airdata chart) & even major ones (the red bars) if you JUST look at one single flight. If you want them all as warnings you will have thousands of messages in GO4 each & every flight. But no one can predict when everything becomes critical & one of the cells will give up. To foresee anything you need to look at ALL flights regarding how the batteries behaved ... judge how the trend is going and eventually decide when enough is enough & take the battery off duty.

You don't understand the point again, no one is talking about minor cell deviations because it's absolutely normal and will not affect the flying in a short term.

I'm talking about major cell deviations that can cause the failure, around 1000 mV. If is not possible to give warnings before that, for example at 200 mV, 400 mV, etc then I really think that it's not a safe system.
2020-3-25
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