Hello, i'm planning to adquire a Phantom 4 Pro to take aereal photographs at a site 4.500 m above sea level and im wondering about the duration of the battery at that elevation. I'm also attaching a Survey 3 camera to have additional filters. Searching forums i have seen some cases around 3.000 m above sea level and their batterys have lasted about 15 minutes instead of the usual ~27 minutes. Has anyone been at this situation to know the problems i might have? or if i should get another drone model (i'm new in all this drone stuff). Thanks! any suggestion is very helpful.

Why don't you experiment little? Try a full battery hovering where you are now and then a full battery hovering at 4500m. Then you will have a good indication of what you can achieve.

Doubt if you can get it that high.

I don't have the drone yet, i would like to know this information before acquiring it. Also can't afford it not working and completely losing the terrain trip.

In the specifications of the model it says it can go up to 6.000 m, so i believe it can or else they wouldn't say it, but battery might last for like 5 minutes, so i would need to have many batterys to take all the pictures i need.

Alexander_Hoch Posted at 2018-2-23 07:53
I don't have the drone yet, i would like to know this information before acquiring it. Also can't afford it not working and completely losing the terrain trip.

In the specifications of the model it says it can go up to 6.000 m, so i believe it can or else they wouldn't say it, but battery might last for like 5 minutes, so i would need to have many batterys to take all the pictures i need.

@ 6K' I'd say less than 10 mins

You will be limited to 1500 meters by the Flight Controller software.

A CW Posted at 2018-2-23 08:13
@ 6K' I'd say less than 10 mins

That seems a bit extreme, it only needs to put the same amount of power into moving air as normal, the extra power needed is just to cover the inefficiency of the props when there is less air density than normal.

How can it possibly use 3x the power?

Nigel_ Posted at 2018-2-23 10:05
That seems a bit extreme, it only needs to put the same amount of power into moving air as normal, the extra power needed is just to cover the inefficiency of the props when there is less air density than normal.

How can it possibly use 3x the power?

Have you flown at that altitude?

Lost me, 4.5 meters is only 14.76 feet. Do you mean 4,000 meters ?

        here is a video of phantom 4 at almost 13000 ft. Maybe this will help

High altitude does not automatically mean high battery drain. At 4,500 Metres you should be OK. There is video of people flying these aircraft at Everest Base Camp. There are actually two base camps on either side of the mountain, but both are at about 5,000+ Metres altitude. As long as you launch from close to the height, you should be fine, but if you try to climb to that altitude from a much lower level, the firmware will stop you.

"I'm also attaching a Survey 3 camera to have additional filters."
I wonder how this will affect it?  I assume one of these: https://www.mapir.camera/collect ... ji-phantom-4-bundle

Spec says 76g, but I just put my Git3 on the scales and it weighs 87g, and there will be a bit more for a mount, plus the GPS is another 30g on my scales.

P4 is quite capable at sea level, but the extra weight will have a lot more effect at high altitude.   Might need a calm day with low wind speeds.

Out of interest, how do the filters help?  I don't expect to find much vegetation at that altitude, but maybe there is in Chile?

The altitude has nothing to do with battery life.

Titanbot Posted at 2018-2-23 14:00
https://youtu.be/m7_PN4gum1A        here is a video of phantom 4 at almost 13000 ft. Maybe this will help

here is a video of phantom 4 at almost 13000 ft
Don't believe everything you see on the internet.
That's a video from someone that's trying to deceive you so I wouldn't believe anything about it.

Look at 0:38 and you see the horizon curve up when the camera tilts down.
That's because it's a Gopro camera which accounts for the engine noise you can still hear right at the end.

Look at 1:27 and check the thing on the landing gear.  That's not a P4.
Look under the motors at 4:33.  That's not a P4.
He's flying with with an old P2.
How high is not certain but he would have had a hard time getting to the claimed 3800 metres and back.
It would have taken a P2 10.5 mins to get to 3800 metres but the return would have required another 31.5 mins and the batteries for the P2 don't have that sort of endurance.

All that you can get from that video is that someone with a P2 flew it high and wants to deceive you about the drone used and the height he got to.

Labroides Posted at 2018-2-23 18:41
here is a video of phantom 4 at almost 13000 ft
Don't believe everything you see on the internet.
That's a video from someone that's trying to deceive you so I wouldn't believe anything about it.

Good eye

I have a phantom4 pro plus and regularly go to 5oom above launch altitude where the height limiter comes in.

I have noticed it takes time and energy to ascend and descend even to that height and that certainly eats into hover time, factor in a bit of strong wind and hover time certainly starts to look a bit weak.

The question I think would be at what altitude would the propellers start to become unable to develop lift.

The only time I get above the clouds is when there is a low fog and things look great when you bust through the fog ceiling hehe...

0 to 13000ft... I'd have to personally see that to believe it..

The Manual does State.    " Aircraft and battery performance is subject to environmental factors such as air density and temperature. Be very careful when flying at altitudes greater than 19, 685 feet (6000 meters) above sea level, as the  performance of the battery and aircraft may be affected".       I too would suggest a hover test in a couple differnt temp ranges. The desity altitude is what is going to cause him problmes. Thinner air meaning the prop will produce less lift. Meaning the motors are going to have to spin ever harder to maintain his altitude.

IamWedge Posted at 2018-2-23 19:56
The Manual does State.    " Aircraft and battery performance is subject to environmental factors such as air density and temperature. Be very careful when flying at altitudes greater than 19, 685 feet (6000 meters) above sea level, as the  performance of the battery and aircraft may be affected".       I too would suggest a hover test in a couple differnt temp ranges. The desity altitude is what is going to cause him problmes. Thinner air meaning the prop will produce less lift. Meaning the motors are going to have to spin ever harder to maintain his altitude.

He is only talking about 4,500 Metres, there are people on here who regularly fly at that height. The real trick is to avoid wasting battery capacity in trying to climb to that level. If he launches from close to that level, then he should be fine.

My elevation is around 7000' above sea level (2100-2200 meters) and my P4P flight time is between 10 and 15 minutes. 15 is when just puttering around in GPS mode or mostly hovering, but if I'm doing missions with lots of forward flight, it can drop to about 12 minutes. Boiling around in sport mode it can drop below 10 minutes. The thinner air does make a difference.
4500 meters would probably be even less, so I'd bring a bunch of batts....

or if i should get another drone model.
Whatever drone you get it will have to deal with the same issues.
It's not the drone, it's the physics of altitude.
Up there the oxygen and nitrogen molecules are further apart so the props have to work harder and spin more to push the same amount of air.
The higher you go, the more this becomes an issue.
If you are just taking photos, that shouldn't be a big deal.
If you wanted to carry out a mapping survey of a big site it would be more of a concern.

luciens Posted at 2018-2-23 20:21
My elevation is around 7000' above sea level (2100-2200 meters) and my P4P flight time is between 10 and 15 minutes. 15 is when just puttering around in GPS mode or mostly hovering, but if I'm doing missions with lots of forward flight, it can drop to about 12 minutes. Boiling around in sport mode it can drop below 10 minutes. The thinner air does make a difference.
4500 meters would probably be even less, so I'd bring a bunch of batts....

I thought forward flight reduces battery drain compared to hover?

Bashy Posted at 2018-2-23 22:11
I thought forward flight reduces battery drain compared to hover?

Only up to a certain point; slow FF where the benefits of translational lift (airflow over the props that help provide more lift) outweigh drag on the aircraft can improve flight times. But faster than that and the copter has to start working harder to overcome parasitic drag and that of course requires more power.

Another effect, though, that would be interesting to see, is the increase in "true airspeed" at high altitudes. It'd be interesting to see how fast you could get a P4P going at 15,000'. You'd probably have to fly it in atti mode to see, but I would think it'd be noticeably faster at full blast up there than at sea level...

ah ok, thank you

ALABAMA Posted at 2018-2-23 07:48
Doubt if you can get it that high.

DJI drones can fly up to 6000m and others have already flown them above the altitude he wants to fly.

Temperature and cold winds are what affect flying.  I would allow 10 mins for photos and the rest of the time for getting drone to where to want to take the pictures, and back.  Bring a few batteries and keep them warm.

luciens Posted at 2018-2-24 06:32
Only up to a certain point; slow FF where the benefits of translational lift (airflow over the props that help provide more lift) outweigh drag on the aircraft can improve flight times. But faster than that and the copter has to start working harder to overcome parasitic drag and that of course requires more power.

Another effect, though, that would be interesting to see, is the increase in "true airspeed" at high altitudes. It'd be interesting to see how fast you could get a P4P going at 15,000'. You'd probably have to fly it in atti mode to see, but I would think it'd be noticeably faster at full blast up there than at sea level...

Even at lesser altitudes 2500m - 2500m in GPS mode on my P3S I have hit 62mph with a nice tail wind using full throttle.

QuadKid Posted at 2018-2-23 08:50
You will be limited to 1500 meters by the Flight Controller software.

Since when are DJI drones limited to 1500m above sea level?  OR did you mean max height from home point which is 500m not 1500m?

luciens Posted at 2018-2-24 06:32
Only up to a certain point; slow FF where the benefits of translational lift (airflow over the props that help provide more lift) outweigh drag on the aircraft can improve flight times. But faster than that and the copter has to start working harder to overcome parasitic drag and that of course requires more power.

Another effect, though, that would be interesting to see, is the increase in "true airspeed" at high altitudes. It'd be interesting to see how fast you could get a P4P going at 15,000'. You'd probably have to fly it in atti mode to see, but I would think it'd be noticeably faster at full blast up there than at sea level...

I think it is only flight distance that is improved with airspeed, not flight time.  If you want to fly as far as possible on 1 battery then fly at ~30mph airspeed, but to fly for the longest time it is probably atti mode and drift with the wind.  I've never seen anyone confirm this though?

As for maximum airspeed at high altitude, I wouldn't be surprised if it was less than at low altitude because although there is less air resistance to overcome, the props are going to be almost maxed out just overcoming gravity which means it wont be able to get much in the way of tilt angle so it can't put much power into horizontal speed, plus the props don't have much air to pull on.

blackcrusader Posted at 2018-2-25 00:50
Since when are DJI drones limited to 1500m above sea level?  OR did you mean max height from home point which is 500m not 1500m?

Yeah I'm in the US I was thinking feet, it's actually 1640 feet or 500M

Nigel_ Posted at 2018-2-25 01:35
I think it is only flight distance that is improved with airspeed, not flight time.  If you want to fly as far as possible on 1 battery then fly at ~30mph airspeed, but to fly for the longest time it is probably atti mode and drift with the wind.  I've never seen anyone confirm this though?

As for maximum airspeed at high altitude, I wouldn't be surprised if it was less than at low altitude because although there is less air resistance to overcome, the props are going to be almost maxed out just overcoming gravity which means it wont be able to get much in the way of tilt angle so it can't put much power into horizontal speed, plus the props don't have much air to pull on.

Agree. In general, max endurance, max distance possible and max airspeed possible aren't going to be the same airspeeds and power settings. Which is which will just depend on the conditions, wind and so on.

As for max airspeed at altitude, I also agree - the maximum power available (to produce thrust) will be the main limitation. I suppose if you qualify it with "all else being equal", the true airspeed will, in general, rise with altitude and the lowering density of the air....

Flight time duration might vary from many aspects, for example, temperature, drone altitude, takeoff altitude, stick input, etc.. It is hard to say for your case, but basically, you can try to do a battery circle, fully discharge the battery and charge to full again.

Rodger8 Posted at 2018-2-23 17:49
The altitude has nothing to do with battery life.

I was getting 20 minute flights at 3000m - 3500m on my P3S.  Even with flights at -10c at altitude.

The issue will be as always wind speeds at location, getting your battery warm for the flight and then watching your voltage level rather than battery level during the flight.  

Just go fly the drone as you normally do.  

blackcrusader Posted at 2018-2-26 19:11
I was getting 20 minute flights at 3000m - 3500m on my P3S.  Even with flights at -10c at altitude.

The issue will be as always wind speeds at location, getting your battery warm for the flight and then watching your voltage level rather than battery level during the flight.  

And last flight, I got just 18 minutes from my P4 at 250m altitude and +5C.  There was a wind that reduced maximum speed to 2Km/h in P mode.

I suspect the biggest difference between these figures is the amount of battery remaining at the end of the flight.  My last flight ended at 12%, but many people will end at 30% and some people land at 50% and are probably even more cautious at high altitude due to the difficulty of retrieving the aircraft after a critical landing.

blackcrusader Posted at 2018-2-26 19:11
I was getting 20 minute flights at 3000m - 3500m on my P3S.  Even with flights at -10c at altitude.

The issue will be as always wind speeds at location, getting your battery warm for the flight and then watching your voltage level rather than battery level during the flight.  

The wind speed if strong will cut down your speed therefore the distance that you can travel.

Labroides Posted at 2018-2-23 18:41
here is a video of phantom 4 at almost 13000 ft
Don't believe everything you see on the internet.
That's a video from someone that's trying to deceive you so I wouldn't believe anything about it.

Yes - the vid has been around for many years.

Here's the original video - the truth is it was with a P2 and less than 5,000 ft:

Here's flying above Jade Mountain Taiwan 3952m.  Drone above 4000m.  Not my video but just to show these DJI drones fly well at high altitudes.