Cold Weather Inspire Deaths

[damoncooper]

I've counted something like 4 reported "dropped from the sky" cold weather induced battery failures and Inspire deaths in just the last 3 days.

All using FW 1.6. All using fairly new battery packs (<20 cycles apparently), all pre-warmed to 20C or higher. All fully charged before flight.

These guys did everything right. Yet. Battery death occurred and their aircrafts dropped from the sky without warning. Two examples below.

Not good.

Discuss.

 

[Zyg0te]

Question is at what point it dropped. I flew mine in -20 celsius a few days ago and I noticed the battery level dropped extremely fast once it got around the 30% mark. Out of curiosity I let it hover over a field with about 1 meter of fresh snow as I had to drain the battery to 5% anyway. At around 10% it just suddenly dropped without warning.

 

[damoncooper]

As I posted in the battery mod thread:

Ok I've tested full main TB48 battery shutdown while in flight with the aux batteries attached with the battery mod and - as expected - the Inspire keeps on flying albeit with a battery error on app. I had full control of the aircraft even though the main TB48 was OFF.

Bring on the DJI battery failures. I'm ready.

Loving my battery mod. Especially with reports of Inspires dropping from the sky due to battery failure and my very expensive X5R on preorder!

 

[gruvpix]

I have been flying quite a bit lately, in temps between -20 and -5 Celsius, so this thread is pretty worrying!
That said I have noticed absolutely no voltage drops on the latest FW version whereas before I used to get them somewhat often. Minus the whole d-log softness issue, this FW version (1.6) has been the best yet for me

 

[Droider]

What do the logs of these crashed Inspires reveal?

 

[damoncooper]

What do the logs of these crashed Inspires reveal?

Two showed critical battery level warning right before dropping out of the sky.

 

[Droider]

And I am guessing that was from a healthy 40/50% to critical in a matter of seconds?
If so DJI will need to replace them as if they were on 1.6 with all the batteries on the latest FW they still ain't got it right..

 

[damoncooper]

And I am guessing that was from a healthy 40/50% to critical in a matter of seconds?
If so DJI will need to replace them as if they were on 1.6 with all the batteries on the latest FW they still ain't got it right..

Correct and yes I would expect so

 

[FlyHighUSA]

This is curious to say the least but I personally am not having any issue with battery voltage dropping suddenly. Although it is a distinct possibility for something like that to happen I have not encountered this yet. Reduce flight times doesn't bother me in cold weather as I expect that but sudden voltage drops and birds falling out of the sky is something no one wants Will monitor closely and report back.

 

[FlyHighUSA]

I was hoping my first post wouldn't be for an Inspire dropping out of the sky but here I am. I lost my Inspire 1 Pro today with 52% battery life. It fell from 49 feet and landed with a thud that I'll hopefully never have to hear again. I contacted DJI today and am sending it in for repair and hopeful that I'll be sent a new unit since this once looks pretty rough as is. It was a new battery(used 3 times) fully charged - kept warm in my running SUV up until the flight. I did the compass dance battery voltage looked fine and was in the green with the battery at 98%. Had insulation stickers on the battery and was running the 1.6 firmware. Being in Minnesota I was very mindful of the cold weather issues with the batteries so I have been extremely cautious flying and making sure my batteries were always fully charged and always making sure my voltage readings were looking good. Take off and hover a bit to make sure everything is looking good and it was. I proceed to slowly move the craft into a shooting position and not moving at more than 7mph as I do this to just make sure things are warming up nicely. Battery and voltage was still reading fine. Then at 75% percent I got a "Overcurrent During Discharge" error. With that my voltage reading was now in the yellow even on hovering. I knew something wasn't right with the battery so I safely maneuver to an open area and slowly worked on the descent. I was at 150ft. and was trying to be very light on the throttles but even the lightest touch put the battery voltage in the red. The battery was still reading 60% though so I wasn't panicking and slowly bringing it down knowing I had a lot of time to get it on the ground or so I thought. At 52% battery life and at 49 feet it fell to the ground and that was that.

Omg man that is terrible. I'm sorry to hear that. It will be interesting to see the data pulled from your bird. I hope it gets resolved soon. Terrible day!

 

[damoncooper]

I was hoping my first post wouldn't be for an Inspire dropping out of the sky but here I am. I lost my Inspire 1 Pro today with 52% battery life. It fell from 49 feet and landed with a thud that I'll hopefully never have to hear again. I contacted DJI today and am sending it in for repair and hopeful that I'll be sent a new unit since this once looks pretty rough as is. It was a new battery(used 3 times) fully charged - kept warm in my running SUV up until the flight. I did the compass dance battery voltage looked fine and was in the green with the battery at 98%. Had insulation stickers on the battery and was running the 1.6 firmware. Being in Minnesota I was very mindful of the cold weather issues with the batteries so I have been extremely cautious flying and making sure my batteries were always fully charged and always making sure my voltage readings were looking good. Take off and hover a bit to make sure everything is looking good and it was. I proceed to slowly move the craft into a shooting position and not moving at more than 7mph as I do this to just make sure things are warming up nicely. Battery and voltage was still reading fine. Then at 75% percent I got a "Overcurrent During Discharge" error. With that my voltage reading was now in the yellow even on hovering. I knew something wasn't right with the battery so I safely maneuver to an open area and slowly worked on the descent. I was at 150ft. and was trying to be very light on the throttles but even the lightest touch put the battery voltage in the red. The battery was still reading 60% though so I wasn't panicking and slowly bringing it down knowing I had a lot of time to get it on the ground or so I thought. At 52% battery life and at 49 feet it fell to the ground and that was that.

Can you possibly pull the flight record from the GO app (use iTunes if on iOS), and upload it to the healthydrones.com site for analysis?

Post back here the screen shots of the flight analysis if you don't mind and maybe we can get a but more insight into what happened.

Very sorry to hear this.

 

[The Editor]

I was hoping my first post wouldn't be for an Inspire dropping out of the sky but here I am. I lost my Inspire 1 Pro today with 52% battery life. It fell from 49 feet and landed with a thud that I'll hopefully never have to hear again. I contacted DJI today and am sending it in for repair and hopeful that I'll be sent a new unit since this once looks pretty rough as is. It was a new battery(used 3 times) fully charged - kept warm in my running SUV up until the flight. I did the compass dance battery voltage looked fine and was in the green with the battery at 98%. Had insulation stickers on the battery and was running the 1.6 firmware. Being in Minnesota I was very mindful of the cold weather issues with the batteries so I have been extremely cautious flying and making sure my batteries were always fully charged and always making sure my voltage readings were looking good. Take off and hover a bit to make sure everything is looking good and it was. I proceed to slowly move the craft into a shooting position and not moving at more than 7mph as I do this to just make sure things are warming up nicely. Battery and voltage was still reading fine. Then at 75% percent I got a "Overcurrent During Discharge" error. With that my voltage reading was now in the yellow even on hovering. I knew something wasn't right with the battery so I safely maneuver to an open area and slowly worked on the descent. I was at 150ft. and was trying to be very light on the throttles but even the lightest touch put the battery voltage in the red. The battery was still reading 60% though so I wasn't panicking and slowly bringing it down knowing I had a lot of time to get it on the ground or so I thought. At 52% battery life and at 49 feet it fell to the ground and that was that.

This 'sounds' very much like a faulty cell in the pack.
Did you open the battery monitor page when you got the message?
Was one cell much lower than the rest?
If one cell dips below around.d 2.89v the back will shut down hitting LVC.

 

[Droider]

If one cell dips below around.d 2.89v the back will shut down hitting LVC.

Thats should just not happen! Yes big flashing warnings but total shut down because one cell is dead is crap. Save the AC but most importantly enable the AC to descend and land 'SAFELY'. not just drop out of the sky. It would be better if DJI wrote the algorithm to descend at a safe decent rate rather than cut the power.

 

[Droider]

@timmywah Do you have the logs off your tablet. Id so stick it up here and we can have a look. Healthydrones have a really good battery diagnosis section.

We also have to remember that these incidents however horrible they are are still few and far between in the grand scheme of things. Healthydromes now have over 200,000k logged so in the real world there must be millions.

Please keep us updated as to just what DJI come back with. Sorry for your failure. Been there and know just how it affects you. Long live WKM. Fly safe.

 

[The Editor]

Thats should just not happen! Yes big flashing warnings but total shut down because one cell is dead is crap. Save the AC but most importantly enable the AC to descend and land 'SAFELY'. not just drop out of the sky. It would be better if DJI wrote the algorithm to descend at a safe decent rate rather than cut the power.

I am not saying it's right (I would rather destroy a $200 pack but get my aircraft back) but just advising that's the way DJI has set the pack shutdown.

 

[Droider]

I am not saying it's right (I would rather destroy a $200 pack but get my aircraft back) but just advising that's the way DJI has set the pack shutdown.

Roger that, I know that Editor. Would be just good to understand DJI's rationale behind it.
I would rather the whole AC vaporised rather than fall like a brick to save a pack!

 

[Droider]

EKK! So hopefully DJI will replace the pack and the copter for free. Have yopu got the full battery history in Healthy drones?

 

[The Editor]

It looks like the battery overheated and cell 1 was at fault. Here I was worried about the cold weather and the battery and craft being cold and it turns out the battery overheats instead. It looks like when it fell from the sky the battery temp was at 139 F.

The pack (and software) can't report on individual cell temperatures since there is only one sensor in the middle of the pack.
The cells have no way of reporting their individual temperature only voltages.
What that guage is saying is the overall temp went to 130f and there were fluctuations in cell one's voltage relative to the others.
Were you not monitoring your battery temp and cell levels during your flight?

 

[filmscum]

Man I hate hearing this! So bummed for you. Hopefully they will replace everything as it's pretty obvious the battery failed. I noticed after a flight yesterday that one of my packs is exhibiting the same behavior in cell 1 as well and looking back at the flights history has done it every time. I'm still in the break-in period and haven't flown it past 48% (only 5 flights on it so far). I'm definitely not using this pack again. Will be
sending it in but not counting on a replacement....

 

[Mad_angler1]

Just some information

Iv seen a lot of healthy drones reports with cell 1 deviations, I'm not saying it's not an issue but see it on flights with absolutely no problems.