shut down the drone to save battery?

[alexjo55]

Sometimes i have been flying really high up and the battery is at like 5%.

Is it possible to shut the drone of and then when its like a few seconds from the ground, i start it again?
Or will it just fumble if you manage to start it and never go back to the correct position?

 

[hansenn]

you mean let it fall down like a brick and then just before it hits the ground start it up again?
You must be joking.

 

[alexjo55]

you mean let it fall down like a brick and then just before it hits the ground start it up again?
You must be joking.

yes.

If you are 500m u, it will take a few minutes to the ground.
But if you let it fall to 100m and then restart it again, you you will save a lot of time and battery.

Wonder if its possible and im not wonder if its a good thing to do.

 

[Yorkshire_Pud]

I theory yes, in practise it is I think questionable whether or not you will be able to restart the motors.
Stopping the motors is easy.
Go into the app menus, find the emergency motor stop option, change the option to "Anytime" then execute a CSC.
The motors will stop once the CSC has been held for around 2 seconds, possibly 1.7 seconds.
The problem lies in the restart and the question is whether or not the drone will, during the free fall, reach angles of tilt that will prevent a SECOND CSC restarting the motors.

If you experiment you do so at your own risk and I would suggest you change the flight mode to Cine before you initiate the CSC, that will reduce the horizontal speed of the drone prior to motor stop and might reduce the chances of the drone tumbling.
If you switch the emergency motor stop option to "anytime" without further experimentation REMEMBER to switch the option back to "Emergency Only". With a two second delay it would be far too easy to inadvertently trigger a mid air shut down.
Note also that I said "second csc" the motor stopping CSC position MUST be released between motor stop and the attempted restart CSC.

However the question i,s why would you fly the drone so high and for so long that this was needed, that is bad flying in my book. Additionally sending the drone above 120m AGL is illegal in Sweden.

Final points,
1) free fall terminal velocity is likely to be in the range 14m/s to 16m/s and quickly reached, so, if you are below 120m then you do not have much time to play with. Even if you start the experiment at your 500m you will have under 1 minute to restart the motors.
2) The drone will not fall from the sky until the battery is below 0%, how far below 0% I have no idea.
3) If you are going to try this PLEASE switch syncing off prior to the flight and copy the .txt flight log and, more impotantly, the .DAT flight log from the screen device ( controller or phone ) to your computer then upload them to here. The DAT might be readable and if so it would be very interesting to see.
4) I would also suggest you do the experiment over the sea or a largish lake.

 

[Meta4]

Sometimes i have been flying really high up and the battery is at like 5%.

The chance you could freefall and save it at the right moment is too small to even consider.
If you are so high up and the battery is at 5%, it's game over because you put the drone in that situation.
Learn to fly properly and avoid getting in that situation.

 

[hansenn]

there are always dare-devils around who have tried it:

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[alexjo55]

The chance you could freefall and save it at the right moment is too small to even consider.
If you are so high up and the battery is at 5%, it's game over because you put the drone in that situation.
Learn to fly properly and avoid getting in that situation.

I have flown into the top of a tree and the drone did like a 360 flip and then back to normal, so i was thinking it had some automatic "flip sensors" that put the drone in its normal position

Also, if i do it over 3 feet of snow, it feels like the chance of it breaking is low.
Maybee have the camera cover on so the camera dont break?

 

[Yorkshire_Pud]

Also, if i do it over 3 feet of snow, it feels like the chance of it breaking is low.

If you are going to try this PLEASE switch syncing off prior to the flight and copy the .txt flight log and more impotantly the .DAT flight log from the screen device ( controller or phone ) to your computer then upload them to here.

The DAT might be readable and if so it would be very interesting to see.

Maybee have the camera cover on so the camera dont break?

Maybe you will damage the gimbal control system and also block air flow through the drone thereby causing an overheat problem.

 

[Starz]

Is it possible

Anything’s possible. Post results when available.
TIA.

 

[MS Coast]

yes.

If you are 500m u, it will take a few minutes to the ground.
But if you let it fall to 100m and then restart it again, you you will save a lot of time and battery.

Wonder if its possible and im not wonder if its a good thing to do.

A few minutes to fall 400 meters? No. Less than 15 seconds.

You do realize that you are damaging the battery by discharging it to 5%?

 

[Dbez1]

I’d skip this experiment if I were you, but then again I wouldn’t be flying illegally.

 

[Cafguy]

Sometimes i have been flying really high up and the battery is at like 5%.

Dead drone flying! it is hugely irresponsible to fly a drone below 12 percnt.

Is it possible to shut the drone of and then when its like a few seconds from the ground, i start it again?

NO not a chance! Drones tumble to the ground- They don't just drop like a flat pancake.
If you own a tinywhoop you can safely give it a try but it would be pure luck if it where to happen.

 

[Yorkshire_Pud]

NO not a chance! Drones tumble to the ground- They don't just drop like a flat pancake.
If you own a tinywhoop you can safely give it a try but it would be pure luck if it where to happen.

fall down like a brick and then just before it hits the ground start it up again?

These raise a point I forgot to mention but since @alexjo55 has not replied to post #4 I don't know if I am 'wasting my breath' however, for the 'benefit' or entertainment of others.

I have done a mid air restart, with a P3.
The drone continued to fall after the restart, at 14+m/s. It took me a moment to realise why, the motors had restarted at idle, it took 2+ seconds for full throttle to halt the fall, it very nearly went swimming.
I suspect a Mini might automatically go to 'full throttle' at restart but I wouldn't want to bet on it. Assuming the drone is falling at terminal velocity I think you'd want a restart made above 100m AGL

 

[BobaFut]

These raise a point I forgot to mention but since @alexjo55 has not replied to post #4 I don't know if I am 'wasting my breath' however, for the 'benefit' or entertainment of others.

I have done a mid air restart with a P3.
The drone continued to fall after the restart, at 14+m/s. It took me a moment to realise why, the motors had restarted at idle, it took 2+ seconds to for full throttle to halt the fall, it very nearly went swimming.
I suspect a Mini might automatically go to full throttle at restart but I wouldn't want to bet on it. Assuming the drone is falling at terminal velocity I think you'd want a restart made above 100m AGL

Yeah, there are plenty of YouTube videos of in-air restarts/recoveries. A drone *might* tumble, but under some circumstances they will fall flat. I'm not sure how much of a tumble DJI drones can recover from because of attitude restrictions and engine power, but to some degree FPV drones can level themselves even if they're tumbling (assuming they have adequate altitude to work with).

In any case I fail to see how a few seconds of this would save you any battery, particularly when you have to give it a lot of throttle to recover.

 

[Cafguy]

Tumble may have been a bit overkill. It will TRY to tumble is probably more accurate.
I think it would be like flying in acro without googles: You may have an idea of the direction the drone will go once the motors start back up BUT I don't think so and probability suggest it will not be level and the drone wouldn't go straight up.
If you have my luck when the drone recovers it will be in a perfect line with your nose.

 

[Yorkshire_Pud]

In any case I fail to see how a few seconds of this would save you any battery, particularly when you have to give it a lot of throttle to recover.

I am not advocating this but let's imgine you wanted to get down from 500m and restart at 150m that's almost a free descent in terms of battery usage.
To lose 350m of height whilst flying would take a mini 3 one hundred seconds, truthfully the choice of a loss of height of 350m was a coincidence, and that must be at a reasonable power consumption.

 

[Dbez1]

I agree with Yorkshire, I doubt if a straight down descent would use much battery.

 

[BobaFut]

I am not advocating this but let's imgine you wanted to get down from 500m and restart at 150m that's almost a free descent in terms of battery usage.
To lose 350m of height whilst flying would take a mini 3 one hundred seconds, truthfully the choice of a loss of height of 350m was a coincidence, and that must be at a reasonable power consumption.

So 100 seconds under power, but at the 14+ m/s freefall you mentioned it would take 25 seconds. So maybe you've save yourself 75 seconds, but a full-speed controlled descent is almost "free" in terms of battery already, so I honestly think a powered descent is more efficient than a zero-power descent + full power recovery.

 

[Yorkshire_Pud]

100 seconds? 350m at the 14+ m/s you mentioned would only be 25 seconds.

I wrote "To lose 350m of height whilst flying", free falling is not flying, it is falling.

 

[BobaFut]

I wrote "To lose 350m of height whilst flying", free falling is not flying, it is falling.

Yeah sorry, I realized that after posting and corrected my response.