GET OUT OF JAIL FREE - WARRANTY CLAUSE - FAKE ANALYSIS

[sumnerwolf]

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Hi

What's your point. Settle is about 100 miles away from both Bradford and Leeds? ??

Your the guy that rings me up and tells me you live right next to me because you can see big ben and blackpool tower out your window arnt you.

 

[tcope]

Hi

What's your point. Settle is about 100 miles away from both Bradford and Leeds? ??

 

[tcope]

Actually it was at the side of a really big hill I was out walking near settle in Yorkshire. Not really big enough to call mountains. But you get the gist

If it hit the hill would you not be able to walk out to that location and look around?

 

[sumnerwolf]

Again? ??? What's your point.


Looking an overview tour highlight. Wind speed 13 miles an hour. Gusts max 38.

Definition of a gust is: a short burst of wind not prolonged.

 

[msinger]

If it hit the hill would you not be able to walk out to that location and look around?

It was too high to hit the hill.

 

[sumnerwolf]

If it hit the hill would you not be able to walk out to that location and look around?

Yes I did do. Spent four days looking with no joy. I live about an hour and half drive away it was a day out walking.

No one is more sorry to not see it again than me it was mine. My issue on that there was wind it was that this is the only factor under consideration from dji. Forget the rest.

Fact is I should not have lost connection. I should have a gps location to find It. . It was moving towards me. Slowly maybe but when it ran low on battery it would have landed and then the controller should have re connected but it never did??

 

[tcope]

Again? ??? What's your point.


Looking an overview tour highlight. Wind speed 13 miles an hour. Gusts max 38.

Definition of a gust is: a short burst of wind not prolonged.

It states that the max wind speed was 38mph as well. The average wind speed for the day was 13mph, with winds up to 38mph. At 700', winds could have easily been 25-30mph. I'm not saying DJI was right or wrong and I'm not saying it was pilot error. I'm only added facts to the post.

 

[AlecW]

Again? ??? What's your point.

His point maybe that it was windy, you were over 4000 feet away and over 700 feet up (much more wind there than lower). DJI said it blew away and the facts do seem to agree with that. Discos can happen for a lot of reasons at that distance, I've found 300 feet high is sometimes better for range than 400 feet for example.

Good luck with your case and sorry for your loss.

 

[John1960]

Be a MAN and accept you dropped a right clanger nobody likes a cry baby you fekd up good style

 

[dwallersv]

Why DJI chose to program RTH flight slower than regular flying is one of the unsolved mysteries of dronedom.
I've never heard a satisfactory explanation.

Hmmm... my understanding is it flies at that speed because the OA is on, which limits it to P mode speed (22mph).

 

[dwallersv]

Thanks for the reply. In your post you put that it's beat to be on the ground at 3.3 which would put it on 50% charge. Also that it was returning at 2 miles per hour. The point is it that it was returning home so why disconnect from the controller when it was getting closer. And then not re connect?? Also ad I only gave one battery because that was what came with it..... I had already been up that day only half an hour before.

Everyone needs to review Li-ion voltage specs.

A regular, 4.2V lithium-ion chemistry is full charge at 4.2V (all voltages cited here are under no load). About 50% at 3.85V, and essentially depleted below 3.7V.

All these figures are reduced about 0.2-0.4V when under load, however when load is removed they pop back (i.e. while hauling-*** back at 45MPH a reading of 3.6V may be 50%, not below empty).

In no case should you ever, EVER take your battery down to 3.3V. 3.6V/unloaded is a low as you should go with it. Damage begins around 3.2-3.3V, and I'm loose with that because the volt "meters" measuring things in these devices are not that accurate (errors of +/- 0.1V isn't uncommon).

 

[Meta4]

Hmmm... my understanding is it flies at that speed because the OA is on, which limits it to P mode speed (22mph).

Obstacle avoidance definitely can't run at full speed.
But RTH speed was always 66% of normal speed, even before DJI developed obstacle avoidance and still flies at the slower speed when OA is disabled.

 

[dwallersv]

Obstacle avoidance definitely can't run at full speed.
But RTH speed was always 66% of normal speed, even before DJI developed obstacle avoidance and still flies at the slower speed when OA is disabled.

Hence your "no good explanation", which I now understand

 

[With The Birds]

Everyone needs to review Li-ion voltage specs.

A regular, 4.2V lithium-ion chemistry is full charge at 4.2V (all voltages cited here are under no load). About 50% at 3.85V, and essentially depleted below 3.7V.

All these figures are reduced about 0.2-0.4V when under load, however when load is removed they pop back (i.e. while hauling-*** back at 45MPH a reading of 3.6V may be 50%, not below empty).

In no case should you ever, EVER take your battery down to 3.3V. 3.6V/unloaded is a low as you should go with it. Damage begins around 3.2-3.3V, and I'm loose with that because the volt "meters" measuring things in these devices are not that accurate (errors of +/- 0.1V isn't uncommon).

These are not regular LiION they are HV so 4.350 v terminal cell voltage at full charge.

Sag may well exceed your quoted figures under high current draw. Battery percentage is determined from remaining Ah estimated from last charge and usage.

 

[dwallersv]

These are not regular LiION they are HV so 4.350 v terminal cell voltage at full charge.

Sag may well exceed your quoted figures under high current draw. Battery percentage is determined from remaining Ah estimated from last charge and usage.

Voltages are a little higher, but for general "rule of thumb" figures, there's no big difference. 15/100ths of a volt math is not something you need to be worrying about when trying to get an idea of how critical your battery is.

Anyway, my main point was to address the "50% at 3.3V" assertion, which is not only wrong, could be dangerous.

 

[Meta4]

In your post you put that it's beat to be on the ground at 3.3 which would put it on 50% charge.

If you start with a 100% battery, by the time it's reading 50% the voltage per cell would be reading approx 3.8V.
The cell voltage wouldn't fall to 3.3V until 30% or lower.

Also that it was returning at 2 miles per hour. The point is it that it was returning home so why disconnect from the controller when it was getting closer. And then not re connect??

This might show why it disconnected and was not able to reconnect.
You flew (green line) up a valley to the right (west) of a hill.

Then climbed to 680 feet as you turned right to fly 330 feet above the hill.
A cross section of the terrain between you and the Phantom when you lost signal shows how close you are to having line of sight blocked by terrain.
The Google Earth topography is approximate but suggests the most likely reason for losing signal was that it was blocked by terrain.

There are many important factors to be aware of in flying a Phantom.
The interaction of battery technology, wind strength at height and the flight dynamics of the Phantom were all involved in this incident.

 

[Method007]

Sorry you lost your drone! It does appear you lost it due to your own choices however, I would definitely not put any blame on DJI.

 

[sumnerwolf]

If you start with a 100% battery, by the time it's reading 50% the voltage per cell would be reading approx 3.8V.
The cell voltage wouldn't fall to 3.3V until 30% or lower.

This might show why it disconnected and was not able to reconnect.
You flew (green line) up a valley to the right (west) of a hill.

Then climbed to 680 feet as you turned right to fly 330 feet above the hill.
A cross section of the terrain between you and the Phantom when you lost signal shows how close you are to having line of sight blocked by terrain.
The Google Earth topography is approximate but suggests the most likely reason for losing signal was that it was blocked by terrain.

There are many important factors to be aware of in flying a Phantom.
The interaction of battery technology, wind strength at height and the flight dynamics of the Phantom were all involved in this incident.

Thank you for your reply. Aside from all the bitching this does help. I'm not getting It back now and I will keep my oppinon as dji are bad news and to stay away because if it. Advertised specs are no where near reality typhoon advertise ranges of about 1.2 km but realistically looking at 1 km. That is reasonable advertising 5km and disconnecting at under 1.5km is just plain false advertising.

But without a tonne of money. No way to fight them for It.

Dji don't give a volts so most of the other posts are redundant. They give a percent remaining battery.

Fact is even at 2 miles per hour it should have still made it back to home and as it disconnected there would be no way to know if it picked up speed after that point. But its safe to say that there wouldn't have been terain in the way as It remains at the hight until it gets to the home point and then desends

 

[jayeverts]

Meta I'm hoping you can help me with an outstanding question on my to find out list. You mention RTH is 22mph in still air. It may well be. To the extent it is however it seems DJI could make an improvement to the firmware that might avert some of these unfortunate outcomes. Flying with the wind we can often achieve ground speeds as depicted in the telemetry as significantky exceeding the advertised specs of the AC. This is, presumably, because leaning on the elevator will cause the AC to assume maximum allowable pitch angle. Why then can't the AC simply apply greater pitch in RTH to maintain a ground speed of 22mph (assuming the prevailing wind allows for it). We know the flight controller is able to determine ground speed as it is reported in the APP, in fact we see it here with therecorded speed being well below 22mph. Might this be because the prevailing wind was within 2mph of the maximum AC spec?

In response to the part about max speed for RTH. This is limited so that the anti collision sensors can work.

 

[rockydog]

T
Dji don't give a volts so most of the other posts are redundant. They give a percent remaining battery.

Fact is even at 2 miles per hour it should have still made it back to home and as it disconnected there would be no way to know if it picked up speed after that point. But its safe to say that there wouldn't have been terain in the way as It remains at the hight until it gets to the home point and then desends

As well as battery percentage, the app also gives voltage readings