battery die in flight

[CanadaDrone]

Really I think the only problem was flying below DJI's recommended battery percentage, where they can no longer be relied upon. Or maybe you just got a bad battery, but either way had it been landed at 30% this would be a non-issue. I don't think there is a lot you can do at this point other than send the logs to DJI and hope they send you a free battery. Maybe someone with more experience repairing drones can comment on whether or not this may be a problem with the drone, but it sure sounds like a battery voltage drop to me, which can happen when you run them low.

 

[Groot]

Because everybody referring to the manual, but nobody actually quoted it (I still can't find the 30% recommendation there. If somebody knows where it is - please share.)
This is something from it (personally tested and working just as explained)

If the current battery level can only support the aircraft long enough to descend from its current altitude a critically low battery level warning will be triggered and the aircraft will descend and land automatically.

 

[killerdog]

the problem was, it didnt just land, it start to spin around,and fall fast

yes, it look like i got bad battery, i put post to see if this happen to anyone else, as i didn't see any post like that,and if i can double check my battery before flight so it will not happen again

as you can see on video, in track it just got to RTH point ( i am always near me at end of flight ), and i was keeping a tof away from red part of bar ( until now spark and air was ok, and i never had drop like this )

also, as i sad, battery is dead now, i can't charge it ( when i try to put it on hub, i got red light and move it away )

worst thing is that i am on trip and will not come back home for 2 more months ...

 

[dvarapala]

One of the things you learn when dealing with rechargeable batteries in any electronic device is that the battery percentage is just an estimate and not always 100% guaranteed accurate. This is true of laptops, smart phones, drones, and anything else that uses these batteries. Next time you fly keep an eye on the battery percentage and you'll see it fluctuating from moment to moment by very large amounts. Thus, ending your flight with 30% capacity remaining may seem excessive until you realize that an estimate of 30% might actually be only 10%. So err on the side of caution and you'll have less to worry about.

 

[killerdog]

and yes, i will do 30% from now on

 

[Groot]

Between 19 and 0% is too much space to be usual battery estimation error. And it didn't go down fast. It jumped directly.

You can try to cycle it from 100% to 2% (not in the air) 1-2 times to see will this improve the estimated %. (And don't worry - 2% will not break your battery)

 

[basophil]

Thanks for posting that question killerdog. I'm new to drones and I learned a lot of useful stuff from this thread.

 

[RayOZ]

@killerdog I would consider that you had a bad battery. It shouldn’t drop 19% suddenly when it’s just hovering. Might be a bad cell. If it’s less than 6 months old and less than 200 cycles, you might want to contact DJI for replacement.
I’ve read some have this issue, but that’s when their battery had been in storage for months over winter.
Have you got a AirData account? It is very useful. My flight logs are uploaded there after each session, and I usually make a cursory check on each flight log, just to make sure batteries are ok and other stuff.
Some people have left their battery on until it goes flat to reset internal logic, perhaps it recalibrated the % battery. I’ve never done that myself, cos I am afraid it’ll never wake up again.
After about 20 cycles, I do let my MP hover around in front of me until about 10%, land and let it drain to about 8%. Turn off, let it cool and charge it up again. I won’t leave at such a low state of charge for a long period. Then fly again until 30%, land and store. That’s my way of battery maintenance.

 

[Groot]

@killerdog I would consider that you had a bad battery. It shouldn’t drop 19% suddenly when it’s just hovering. Might be a bad cell. If it’s less than 6 months old and less than 200 cycles, you might want to contact DJI for replacement.
I’ve read some have this issue, but that’s when their battery had been in storage for months over winter.
Have you got a AirData account? It is very useful. My flight logs are uploaded there after each session, and I usually make a cursory check on each flight log, just to make sure batteries are ok and other stuff.
Some people have left their battery on until it goes flat to reset internal logic, perhaps it recalibrated the % battery. I’ve never done that myself, cos I am afraid it’ll never wake up again.
After about 20 cycles, I do let my MP hover around in front of me until about 10%, land and let it drain to about 8%. Turn off, let it cool and charge it up again. I won’t leave at such a low state of charge for a long period. Then fly again until 30%, land and store. That’s my way of battery maintenance.

Thank you for the great AirData tip. Great platform!

 

[Air Beetle]

Pages 13 thru 15 of the manual. You might want to review the rear status light meanings too. The bottom line is if the status light is not green, you need to take action. The battery and RTH settings are in your settings screen.

 

[4x4_Paul]

Apparently rather than returning to home at 30% you need to be out-of-the-air by 30%. So noted. Pen and ink corrections made to my manual. You'd think DJI would have caught such an error in all their revisions of the manual.

I wouldn't have expected DJI to program their drones to fall from the sky except when the battery reached something closer to 0% battery. Odd that they did that and glad the people here know that poor programming decision so well. Those that are saying that the drone falls-from-sky at 19% why would that be a valid programming decision on DJI's account ... a bunch of the engineers sitting around the table working on the software and rather than going with the group of engineers arguing we ought to make flight safety the number one thing, drain that battery to 0% remaining to keep safe .... but the team that said somewhere under 30% let the drone fall-from-the-sky won! Doesn't make rational logical sense to me.

0% is a bad place to get to, no argument there, but falling-from-the-sky at some random point below 30% as people here have claimed is really bad. Too late to get my money back.

I thought that the 30% was the time to hustle your drone home. Stop playing or filming and work on the process of returning the drone in the straightest path possible towards a safe landing spot just like the original poster was doing. I was fooled by the same language in the manual and the many training videos.

(lots of sarcasm indented but no hurt feelings meant!)

No drones ought to not be falling out-of-the-sky while they have 19% of their battery left.

 

[Air Beetle]

What? They don’t fall out of the sky. They auto land. Please read the manual pages 13 to 15 again. And look at the chart I posted on batteries. They ALL go to zero slightly below 20%. To blame DJI for a battery trait is silly.

I guess DJI so show a percentage of 0% when the battery is at 30%. Would that make you happy? Your car does that now. When the gas gauge is at zero the car keeps going for awhile.

 

[Air Beetle]

You get a warning based on the current conditions that it’s time to return. You can over ride it. You got get another warning that the battery is low and it’s time to land. You ignore that too. You get a third warning that it’s taking over and landing where it’s at. I believe you can push pause and ignore it a third time. Then you get a link to this forum (not really) so you can come and cry about it. Wow.

 

[DesJardins]

You’re all sorts of wrong...

The manual doesn’t equate to real life issues and that’s the problem. The OP’s craft did indeed drop out of the sky far above 0% period so the topic isn’t about the manual, car gas gauges saying empty when you have 20-30 miles left or any other hypothetical analysis on how these “should read”

It comes down to the fact that the drone should recognize a voltage drop, thresholds or limits in remaining charge and autoland like 99% do when it’s necessary. I consistently run mine below 19% on long range flights and monitor the battery health when I get home so if it fell out of the sky instead of auto landing based on the system requirements I’d be ticked off too

The OP has a battery issue in some shape or form in my opinion and that’s not to say it’s something that I don’t know because not one of us can tell him the exact reason.

Step back from being a forum commando people

 

[Groot]

Air Beetle,
You still use your graph, as a reference point, and I still insist there is no such thing as universal battery percentage graph. Every battery has it's own graph, and depends on too many things, including programming decisions how to present this to the customer. That's why the old nokia phones were last days on small % battery and some of the new smartphones goes from 10 to 2 for 1 hour. And if something jumps from 19% to 0% for a seconds without even consider all digits in the middle, there is something wrong.

And I am asking one more time - what do you thing these % are from? What are these 19% actually? .

 

[Air Beetle]

I'm telling you that the chart is a teaching aid. Sure you can get a reading of 19% but from 20% down its a steep cliff and there are countless web posts that warn you not to venture into that range. Groot you clearly don't understand electricity by your comments. Yes, you can venture into that cliff range but if you suddenly apply a load to the battery it will drop sharply. I gave the gas analogy to help. Using it again, I could let my car idle on empty for hours but as soon as I go full throttle down the freeway it dies much sooner.

Until the OP posts a log this is all just speculation.

 

[Groot]

I'm telling you that the chart is a teaching aid. Sure you can get a reading of 19% but from 20% down its a steep cliff and there are countless web posts that warn you not to venture into that range. Groot you clearly don't understand electricity by your comments. Yes, you can venture into that cliff range but if you suddenly apply a load to the battery it will drop sharply. I gave the gas analogy to help. Using it again, I could let my car idle on empty for hours but as soon as I go full throttle down the freeway it dies much sooner.

Until the OP posts a log this is all just speculation.

With people like you I practice my nice and tolerant communication.

Thank you.

 

[JDawg]

Please post your flight log and ignore those who should be ignored.
How to retrieve a V3.DAT from the tablet

 

[mavicn00b]

I am not a fan boy. My Air is one of my drones in my fleet. IF you read the manual, you will find that the standard warning is at 30% and it returns to home. You obviously disabled it so let's cut the word games.

Mavic Air low battery

Look at the discharge curve for lithium batteries. They fall off a cliff at around 20%. This is true for electric cars, cell phones, and drones. You are the one who doesn't pay attention and won't take time to learn. You are going to lose your drone if you don't slow down and read the manual.

I'm not going to spoon feed you any further.

Nice graph but DJI batteries are typically 3.5v at 0% rest voltage.

 

[Air Beetle]

I give up. I guess it is too difficult to comprehend. The manual clearly states that it calculates the energy to get back to the home point and warns you to head back. You have to IGNORE that suggestion to continue with your flight. Everything after that decision to ignore the low battery warning is on you.

To the relief of all of you that think I am the bad guy, I'm out.