Mavic 2 Pro fell from sky after 5 min of flight

[Bartels]

My Mavic 2 Pro fall from the air and I can figure out why. The location was clear, battery was full... could any experts here have a look at the log please? The drone is a write off as 3 motors, one arm, gimbal are damaged beyond help and the whole body is missaligned but I'd still like to know whether it was my error or something else

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[sar104]

The battery data look fine, but the event occurred immediately after you centered the elevator from full forwards and around 10 m/s forward velocity.



While it's not recorded, due to the telemetry latency, that will have caused a sudden positive (rearward) pitch excursion, which puts significant force on the battery latches. If they are not fully engaged, or if the battery is somewhat puffy, that can lead to a battery disconnect. Circumstantial, but almost certainly what happened here.

 

[Bartels]

****, an expensive rookie mistake indeed:/

The battery is a bit puffy (as are the other 2 I have), didn’t know that the latches are not so strong

I don’t see it in the log but just before I lost connection the drone showed proximity warning... when I collected it I noticed quite a number of birds in that area. Could it be possible that something hit it from the back?

 

[sar104]

****, an expensive rookie mistake indeed:/

The battery is a bit puffy (as are the other 2 I have), didn’t know that the latches are not so strong

I don’t see it in the log but just before I lost connection the drone showed proximity warning... when I collected it I noticed quite a number of birds in that area. Could it be possible that something hit it from the back?

A mid-air collision, unless it were itself catastrophic enough to dislodge the battery, would show up in the telemetry. The attitude change at the end of the log record is a much more likely explanation.

 

[Bartels]

Thank you sar! Lesson learned, now off to get a new one & all permits

 

[AMann]

Thank you sar! Lesson learned, now off to get a new one & all permits

Sorry that happened to you! You mentioned your other batteries have the same issue being swollen, are you flying in extreme temps?

There is a battery maintenance thread here: HOW TO: Maintain and store your DJI Mavic batteries | Mavic Help

There are also some velcro straps and various clips sold to help lock flight batteries in better.

Also, don’t fly with puffy batteries, use them as portable USB charging powerbanks (there’s a USB adapter clip that came with your drone).

Good luck!

 

[Bartels]

@AMann after the accident I noticed that all 3 batteries don’t have even bottom anymore, it’s tiny bit concave... it does get hot here in Saudi during summer and I rarely flew with the drone, wanted to resume now as it feels like summer in Europe.

Thank you for the link and the tip on the Velcro strips! Out of curiosity, is anyone using some sort of emergency parachute for his drone?

 

[AMann]

@AMann after the accident I noticed that all 3 batteries don’t have even bottom anymore, it’s tiny bit concave... it does get hot here in Saudi during summer and I rarely flew with the drone, wanted to resume now as it feels like summer in Europe.

Thank you for the link and the tip on the Velcro strips! Out of curiosity, is anyone using some sort of emergency parachute for his drone?

I don’t know about parachutes, but I am careful about battery temperature when I fly out here in our deserts when the temperatures rise above 38° C. I’ll just fly a battery once and then put it away to cool off if it is warm on days like that. (as I help out my wife’s archaeology company with doing aerial photos, I have six batteries that I rotate through and do not recharge them if they are at all very warm.)

 

[MAvic_South_Oz]

are you flying in extreme temps?

It doesn't look like the OP flew in their summer, but neighbouring Qatar is now installing outdoor airconditioning in some venues !!

https://www.washingtonpost.com/graphics/2019/world/climate-environment/climate-change-qatar-air-conditioning-outdoors/

Storage in extreme temps day in / day out could also be an issue if not in a cooler controlled space like home or office.
If batteries were left in a vehicle for example, it could be as bad as flying in those sorts of 116f / 46c temps, maybe a lot worse.

 

[Bartels]

It doesn't look like the OP flew in their summer, but neighbouring Qatar is now installing outdoor airconditioning in some venues !!

https://www.washingtonpost.com/graphics/2019/world/climate-environment/climate-change-qatar-air-conditioning-outdoors/

Storage in extreme temps day in / day out could also be an issue if not in a cooler controlled space like home or office.
If batteries were left in a vehicle for example, it could be as bad as flying in those sorts of 116f / 46c temps, maybe a lot worse.

@MAvic_South_Oz The batteries were never left in a car or hot environment and were always stored in a bag... we have dry heat here in Saudi. I'll keep a close eye on the link on how to store and maintain Mavic batteries while I'm here.

 

[MAvic_South_Oz]

The batteries were never left in a car or hot environment

No worries, was just advising in general of a scenario where they can be affected quickly.
Dry heat is better than humidity, I'm talking personal comfort there more than batteries

Hope you can get more flying in now the hottest part of the year is pretty much done there.

 

[AMann]

@MAvic_South_Oz The batteries were never left in a car or hot environment and were always stored in a bag... we have dry heat here in Saudi. I'll keep a close eye on the link on how to store and maintain Mavic batteries while I'm here.

If you store the batteries fully charged in a bag, they can get quite hot by themselves when they are self-discharging. Mine were hot in my case when I neglected to take them out and they started to auto-discharge by themselves after three days of storage. Luckily, I think they survived and were not swollen. Now, I try to fly all my batteries I charge, or then use them to charge up my phones and iPad when I get home. I also store them and charge them on a metal fire resistant shelf in the open when I get home.

I suspect that you may have done the same mistake I did to end up with swollen batteries, sorry about that.

 

[RickinWaST]

Sorry to read about your drone crash!

 

[silverdragon]

I installed this to help secure battery. I also removed the screw and attached the LumeCube Strobe on it. So I have battery security and strobe for day and night flight

 

[hiflyer201]

The Mavic Air batteries have small tabs on the four corners of the bottom. I have three batteries. two sit flat but one of those is slightly puffy after a flight. the other battery is shall we say ..junk.
The question is. I have six batteries for my spark and both drones and batteries have been stored and used in the same Environment. The Batteries for the Spark are perfectly sound and that is not the case with the Air. There seems to be a lot of bad batteries out there and I'm not so sure that it is all user caused