Auto-landing at 12% VERY close to home ... normal?

[OneQuickSix]

Hi, I've been caught off guard a few times now when the Fly App initiates an AUTO-LANDING sequence -- and the ensuing terror that follows. ? Although, the last time or so I think I kept my heart-rate under/around 100, lol, and was mostly in-control of my faculties.

Anyway, recently I had it kick in when the battery hit 12%. I was at an alt. of ~350-375ft, and only about 31 ft. from home base. I was expecting it at around 10%, so not a huge deal, but just wondering why it kicked-in early?

Is this because of the altitude? It was so close to home, and that is not that high really, seems like it would have known that it had plenty to move the thirty or so feet and land. RTH I could understand, but why the auto-land. It landed with 10% battery left. I know you don't want to cut it super-close, but with 10% left over (not even considering the "hidden" charge it has beyond this -- as I understand), that's at least another 3 minutes (which is actually quite a bit) before 0%. The manual says critical battery is less than 5%, with low battery 6-10%. So what am I missing?

Thanks!

PS> Winds were calm ... max gusts were only 8mph that day.

 

[old man mavic]

well the proximity to the home point ,is why it just landed for a start ,if you had read the manual you would have known that ,because you were at almost the max altitude then it calculated how long it would take to descend and factored that into its remaining battery life as well,when lipos get below around 30% charge the voltage drops off a lot quicker than it does when the battery is fully charged, so flight time is reduced ,you cant judge the percentages as being absolutely accurate ,you will notice that the remaining charge level will increase slightly after shutting off the battery and allowing it to cool

 

[Meta4]

Anyway, recently I had it kick in when the battery hit 12%. I was at an alt. of ~350-375ft, and only about 31 ft. from home base. I was expecting it at around 10%, so not a huge deal, but just wondering why it kicked-in early?

It landed with 10% battery left. I know you don't want to cut it super-close, but with 10% left over (not even considering the "hidden" charge it has beyond this -- as I understand), that's at least another 3 minutes (which is actually quite a bit) before 0%. The manual says critical battery is less than 5%, with with low battery 6-10%. So what am I missing?

It sounds like you think the drone should use up every drop before coming in to land as close to zero % as possible.
If you were in the pilots seat of a small plane, you'd probably follow a different philosophy and value a comfortable safety reserve for times when the unexpected happens.

We can't see the data which would show the actual battery voltage rather than percentage indication which may not be accurate.

Hidden charge ??? I wouldn't count on that at all.

 

[OneQuickSix]

... ,if you had read the manual you would have known that ...

Ouch. I've read the manual ... at least three times. I read manuals BEFORE I get the product! Always have, always will. I was the kid in the 80's reading the 500-page flight sim manuals before cracking open the 5 1/4 floppy disk(s). I just thought it was closer to home for that to kick in. My reading comprehension isn't what it used to be though, admittedly. ?

...because you were at almost the max altitude then it calculated how long it would take to descend and factored that into its remaining battery life as well,when lipos get below around 30% charge the voltage drops off a lot quicker than it does when the battery is fully charged, so flight time is reduced ,you cant judge the percentages as being absolutely accurate ...

Gotcha, thanks for the info. I know they fluctuate. Why did DJI drop the nice little bar/indicator "thinga-ma-bob" that was in DJI GO? That graphic made more sense to me then just a straight-up percentage. Never got to use GO, but saw plenty of videos of people using it.[/QUOTE]

... you will notice that the remaining charge level will increase slightly after shutting off the battery and allowing it to cool ...

I did notice that, and also wondered about the power out perhaps being on a curve, rather than a linear dropoff.

 

[old man mavic]

@OneQuickSix ,you will make you batteries last a lot longer if you aim to be on the ground by 30%, pushing them to the limits will shorten their lifespan, happy flying OMM

 

[Meta4]

I did notice that, and also wondered about the power out perhaps being on a curve, rather than a linear dropoff.

At 20% your drone still flies and climbs just as fast as at 100%

 

[OneQuickSix]

It sounds like you think the drone should use up every drop before coming in to land as close to zero % as possible.

No, not at all ... I usually bring it in in the 20-30% range. But I was getting a particularly incredible and beautiful timelapse (I really lucked out with some cool weather effects), AND the drone was literally a stone's throw away ... horizontally speaking. On previous flights of a similar nature/proximity, I had it back home and landed in under a minute, so I though it should (and it was) fine. That's why I'm asking ... it just didn't add up to me.

If you were in the pilots seat of a small plane, you'd probably follow a different philosophy and value a comfortable safety reserve for times when the unexpected happens.

100% agree. Have flown thousands of hours virtually (but taken seriously), and know about fuel reserves, etc. But again, this seemed very much with in safety parameters given the proximity.

Hidden charge ??? I wouldn't count on that at all.

NO, I wasn't "counting on it" ... I was just mentioning it as part of the overall question of why it started the auto-land with OVER 10% battery, especially when it was so close to home. Now I know ... it was the proximity and nothing to do with the battery, at least not entirely.

In the end it used (as I would expect) about ~2% of the battery to fly ~450 feet, with me fighting the auto-landing.

 

[OneQuickSix]

well the proximity to the home point ,is why it just landed for a start

Actually that is not why (who isn't reading the manual now, my friend! ) ... the manual says "less than 5 meters" away, which is ~16.5 feet. I was close to double that away from the home point.

So, it's still a mystery to me. I feel like it has done this before, with even more battery life, with approximately the same proximity, maybe a tad farther ... like 60-100 feet away.

 

[Meta4]

That's why I'm asking ... it just didn't add up to me.

As with all flight mysteries, you really need to look at the recorded flight data to see what really hapened rather than relying on what you think might have happened.

NO, I wasn't "counting on it"

I wouldn't count on something I've never heard of.
Hidden charge? Is that a real thing?

 

[OneQuickSix]

At 20% your drone still flies and climbs just as fast as at 100%

Is that also true in the low teens, 10%, below 10% levels?

Also, at the time it switched to auto-land, the Voltages were:

10.84V

3.615V

3.615V

3.609V

0.006V

A minute earlier (and at around 15% capacity), the voltages were practically the same. So it doesn't look like there was a big drop in voltage.

Thanks,
Tim

 

[OneQuickSix]

I wouldn't count on something I've never heard of.
Hidden charge? Is that a real thing?

Neither would I, so we're in agreement there. But I have -- and am STILL not counting on it, just in case that still isn't clear -- read somewhere that the 0% reported by the app is not a "true" 0%. " I guess one could drain it to 0% (not great for the battery of course) and then use a multimeter, or the like, and measure it.

 

[Meta4]

Is that also true in the low teens, 10%, below 10% levels?

Up to some point it will be true.
I fly in situations were a healthy safety margin is critically important so I never take it low enough to know for sure.
Maybe the rate at which the battery is being depleted varies?
It's an area I haven't investigated and there are a few variables to complicate things, so I'm not sure

Also, at the time it switched to auto-land, the Voltages were: ...

One line of a couple of numbers isn't enough to tell much at all.

 

[Gkinghrn]

i would prefer to see the empirical flight data before we all jump to conclusions

 

[Pushkur]

Neither would I, so we're in agreement there. But I have -- and am STILL not counting on it, just in case that still isn't clear -- read somewhere that the 0% reported by the app is not a "true" 0%. " I guess one could drain it to 0% (not great for the battery of course) and then use a multimeter, or the like, and measure it.

You are so polite when replying to criticism you didn't deserve.....think it’s an age thing ??‍???
I wonder what the average age is on this forum ?

 

[dtb24]

Neither would I, so we're in agreement there. But I have -- and am STILL not counting on it, just in case that still isn't clear -- read somewhere that the 0% reported by the app is not a "true" 0%. " I guess one could drain it to 0% (not great for the battery of course) and then use a multimeter, or the like, and measure it.

I did a test just for kicks and can confirm I got a few more minutes after it hit 0%

 

[Motorcycle Rider]

At 0% according to the screen read out, it still flies for a couple of minutes.

 

[OneQuickSix]

You are so polite when replying to criticism you didn't deserve.....think it’s an age thing ??‍???

Thanks, yeah it honestly did feel a little hostile for no reason, but I figured, "Hey, I'm new to the forum, and sometimes people just misinterpret your meaning and/or add "tone" that isn't there." And yeah, I'm getting pretty old ... hopefully mellowing with age, lol. Maybe it's my avatar ... he does look like some punk kid, no?

I wonder what the average age is on this forum ?

Make a poll!! (If there hasn't been one already.) I was wondering that as well, would be an interesting demographic. I'm sure there is already some data on it out there in the ether though.

 

[OneQuickSix]

I did a test just for kicks and can confirm I got a few more minutes after it hit 0%

At 0% according to the screen read out, it still flies for a couple of minutes.

Thanks guys for this info and confirming what I read and thought. Wow, a "couple of minutes" ... that is quite a bit actually, and is somewhat reassuring in a case where the drone autolands, crashes etc. far away.

 

[Meta4]

Thanks guys for this info and confirming what I read and thought. Wow, a "couple of minutes" ... that is quite a bit actually, and is somewhat reassuring in a case where the drone autolands, crashes etc. far away.

Nothing has been confirmed.
We still can't tell what happened in your flight as the flight data has not been made available.

 

[OneQuickSix]

No, it was confirmed. I was referring to the “battery has more charge after reaching 0%” claims from some of the other, helpful, people. One person claimed minutes after 0%, which -- as I stated -- is quite a bit. I'll probably try it myself one day this week if I get time.