MAVIC AIR SUDDEN CRASH FOR LANDING from 70% battery sudden Drop to 0%

[Xyford]

I work hard to buy my drone. I bought Mavic Air only because thats what could i only afford. Im from philippines. I bought my drone from FB marketplace 2nd owner. 1 battery MA1
I test flight it before i bought it. 3x. I also check the flight data and battery status. The battery already had a 40+ cycles.

Before the drone FORCE landing. I already check the homepoint. and check the battery level. I was doing sportsmode. Pics bellow. from 70% suddent drop to 0% so it was force landing to the sea.

Man its so sad. I cant buy a drone again.

 

[slup]

Unfortunately batteries aren't "just another hardware"... it's chemistry & not only charge cycles wears & age them. The percentage you see in the GO4 app is just a calculation out from the voltage from start... if the discharge then later behave outside the normal pattern the Battery Management System (BMS) will give up & say 0%. Usually a critical low voltage auto landing starts when one or more cells falls below 3.0V.

If you share the .TXT flightlog from this flight (it's stored in the screen device you used, & not in the drone or RC)... we can see exactly how the battery cells behaved & what failed.

Go here & upload the log which is stored in the screen device you flew with --> PhantomHelp Log viewer
Then share the link they provide once you've uploaded in this thread, in a new post.

(Scroll down a bit there & they describe exactly where in your screen device the logs are stored)

 

[spsphotos]

Or....the battery came loose and the connection failed. Seen that happen.

 

[slup]

Or....the battery came loose and the connection failed. Seen that happen.

Usually doesn't generate a battery percentage to go 0% & start up a auto landing... if a battery gets dislodged it's a immediate power loss & the drone falls.

 

[Kuiper Denizen]

Or....the battery came loose and the connection failed. Seen that happen.

I always check on my batteries for swelling. Place it right side up on a flat surface. (The underside where the battery information is printed is flexible and where the swelling causes it to bulge.)

If the battery can rock left to right it has begun to swell. As the swelling increases with each use, it will require a stronger push to “click” it in place.

If the swelling gets to that point, requiring effort to get the click, it really should be properly disposed of. The swelling, which may only increase as it’s warming while powering the drone, may pop it loose.

If that causes a crash where the drone can be recovered and the battery has separated, that might indicate what happened.

If all is lost completely, only the flight data may be able to show what happened, but not necessarily why.

Preflight inspection should always be done to insure that all systems and attachments are functioning as they should.

I doubt anyone would be willing to get aboard any flight where the pilot neglected those procedures. Shortcuts only save time, not equipment. Or passengers, for that matter!

 

[Paul Harvey]

Sorry I can't help, I just wanted to say the same thing happened to me with my Air 2S. When I finally found the drone and inspected the battery I found no swelling or anything that would cause concern. I've used the same battery since then with no problems.

Hope you can find your drone, good luck!

 

[slup]

...the same thing happened to me with my Air 2S. When I finally found the drone and inspected the battery I found no swelling or anything that would cause concern. I've used the same battery since then with no problems.

Swelling is caused by gassing coming from electrolyte decomposition... if the swelling occurs suddenly & critical enough during flight it can make the battery to dislodge from the drone. This will not cause a "critical low battery voltage" auto landing... it will cause a sudden power loss and there the drone will fall as a rock.

"Critical low battery voltage" auto landings is caused by either a total cell failure or a very high internal resistance in one or several cells making the cell voltage drop below 3.0V during amp draw (yeah... that's the min. level before permanent damage of the cell occurs)... this will not show on the outside of the battery pack, you will only notice it once it happens again or if you follow the trends regarding voltage drops & cell deviations over several flights.

If I were you... I wouldn't trust that battery for any flights where you can't handle another auto landing, preferably only use it for desk duties.

 

[samysys]

based on the background, a poor conditioned battery is the most likely cause. Yet, the log (.dat +.txt) can tell.

I have similar experience with drones from Autel (EVO II Pro) before. The new battery (charge cycle < 10) just drops 0% within seconds during flight. I experienced it three times in field: I thought it was my pilot error first time, and fly again with the same battery (after tested and re-charged the same battery) and it happened again. I changed another well conditioned, new battery (from the product serial number, it should be in different batch of production with the first battery) but still have the same problem. I was lucky in all occasions that I managed to recover everything.

I reconstruct everything indoor and found that the battery actually still had juice in it when it was shown "0%". It can still hover normally as any other battery.

There were others who reported similar incident in the forum but they were not able to recover their bird for investigation. Nor was the Autel responsive, so the exact cause was not concluded.

Yet, I believe that the cause of the problem is likely to be firmware. Anyway, I grounded that bird.

It's not related to the OP's case. just sharing.

 

[samysys]

I always check on my batteries for swelling. Place it right side up on a flat surface. (The underside where the battery information is printed is flexible and where the swelling causes it to bulge.)

If the battery can rock left to right it has begun to swell. As the swelling increases with each use, it will require a stronger push to “click” it in place.

If the swelling gets to that point, requiring effort to get the click, it really should be properly disposed of. The swelling, which may only increase as it’s warming while powering the drone, may pop it loose.

If that causes a crash where the drone can be recovered and the battery has separated, that might indicate what happened.

If all is lost completely, only the flight data may be able to show what happened, but not necessarily why.

Preflight inspection should always be done to insure that all systems and attachments are functioning as they should.

I doubt anyone would be willing to get aboard any flight where the pilot neglected those procedures. Shortcuts only save time, not equipment. Or passengers, for that matter!

placing it on a flat surface works for some battery (e.g. mavic 2) but I doubt it works for some(e.g. mavic 3/M30), given their structure difference. Anyway, it is good (and absolutely necessary) to check before flight.

I have an additional safety practice ("in-flight inspection", if you would like to have a name for it): immediately after take off, I check the battery information in the controller. If they voltage between different cells are over 0.1V, I will not continue the flight and land it for battery change. I will also have a mental notes on the battery temperature.

As long as condition permits, I would repeat this during flight (e.g. between recording of clips) to check if there are high voltage differences or extreme increase in temperate. Both indicate abnormality of battery.