My Anafi has now also fall out of the sky. :-(

[Vassilag]

I agree with it, but the machine is unable to calculate with accuracy how much energy will be needed in every case. A sudden wind burst makes bigger difference than the temperature of the battery IMHO. Also please keep in mind that returning to home Anafi will fly at the minimum RTH altitude you have set. 30 meters by default.

In general automatic RTH should not be guaranteed. On the other hand I noticed that the entire flight lasted only 16 minutes which is less than usual. Either the machine faced strong winds ( the wind speed at 100 m is very different than surface) or the battery has lost capacity.

Regards, Vassilis

Sorry but it was one of those rare days where there was no wind here on the place. Anafi flew "only" 50 meters horizontally to get over the home point. According to the log, 73% of the battery's capacity has been used.

The battery could not charge more power even though it "only" showed a residual capacity of 92% when it was insert into Anafi. Hence the shorter flight time.

You can also look directly at the graph of the log that Anafi flew at 100 meters high to the home point and began the descent as she "folded the wings together" and fell to the ground.

Regards, Leif.[/QUOTE]


I have my Anafi only 3 months now and I have only 30 flights - so I am a newbie here - but I have noticed (twice) that charging the Anafi with a computer's usb my battery didn't reach 100% charged. Both times, the charging stopped automatically at some point but when I tried to fly I saw that the battery was only 92% (!) charged. You may didn't charge it with a computer but it could be a "charger" thing.

BTW, Thank you *very* much for sharing this case, because there are a lot of things for a newbie to learn!

Regards, Vassilis

 

[Landbo]

I have my Anafi only 3 months now and I have only 30 flights - so I am a newbie here - but I have noticed (twice) that charging the Anafi with a computer's usb my battery didn't reach 100% charged. Both times, the charging stopped automatically at some point but when I tried to fly I saw that the battery was only 92% (!) charged. You may didn't charge it with a computer but it could be a "charger" thing.

BTW, Thank you *very* much for sharing this case, because there are a lot of things for a newbie to learn!

Regards, Vassilis

No I never charged my batteries from a computer. I use either a 5 Volt 3A USB charger or a 45W PD charger. The battery I used on the flight was filled up completely with my PD lets on January 5 after a flight.

Thanks. Our flying gear, we are paying a lot of money for, should obviously not just fall out of the sky. I'm looking forward to hear what Parrot says to the case.

Regards, Leif.

 

[zandoli]

January 5th? Flew on the 10th?

 

[Landbo]

January 5th? Flew on the 10th?

Yes that is correct.

Regards, Leif.

 

[pedrosfia]

Mine fell 24Th Decemeber. They keep asking to enable sharing, in flight stats. Everything is enabled, I've sent flight stats of all my 4 flights, 15 days ago.... Still got no answer... Hope you get more luck than I do ! Terrible customer service... They ignore every e-mail, and when I contact by telephone they just say they're answering that day, and nothing happens...

 

[Landbo]

Mine fell 24Th Decemeber. They keep asking to enable sharing, in flight stats. Everything is enabled, I've sent flight stats of all my 4 flights, 15 days ago.... Still got no answer... Hope you get more luck than I do ! Terrible customer service... They ignore every e-mail, and when I contact by telephone they just say they're answering that day, and nothing happens...

I hope you soon hear from Parrot. Remember it has been a lot of holidays within the last to weeks.

So far I have got a case number and they has promise to return within 48 hours, which must be tomorrow if they also have to stay on weekend too. I will assume they send an email tomorrow and ask for my log for that flight that ends 36 meters up in the air with 7% power left on the battery, according to the log. Then I have to see what they say. In any case, my Anafi is grounded until I get a clarification of what happened.

Regards, Leif.

 

[AugerIn]

Remember that battery voltage is not linear, there will be a big dip at either end, and a probably a curve in the middle, and it's quite difficult to predict capacity left when discharging without knowing the rate of discharge ( which is a thing in the future - how would it know that you were going to sit still for five minutes idling, then request more power to accelerate and fly back? ).

Cold weather is going to make this worse, this dip will come earlier, but it'll be even less predictable - increased load on the battery will warm it up on the inside of the battery, allowing more current draw, but depleting it faster than if it was warm on it's own from the outside temperature. You can't just rely on temp of battery alone, because the battery will work harder to draw power faster which warms the battery itself. You don't know what the temp is internal to the battery because there is no probe on the inside of the cell, just strapped to the outside, so there is a bit of delay getting the exact temp anyway - if it's cold but you see 11.9 volts, is it cool but low because you're seeing the result of the cold, or is it super warm just now on the inside but the battery is on it's last gasp?

Even if you know the exact variables, outside temp, internal battery temp, constant amp draw, it's difficult to get that last 5-10% exactly predicted where it will drop, especially where we're getting our voltage from the drop of two cells that we've been drawing down from almost full voltage - if they were balanced when we started, they certainly are a bit out of balance now near the end of their capacity, and one will be inevitably trying to make up for the shortcoming of the other.

When you stop drawing current the battery has a chance to recover for a second and you'll start seeing a higher voltage - we've probably all see where a battery in an item is dead, but then you turn the item off and turn it back on and it's working for a few seconds.

Guessing the percentage left is a tradeoff. One solution is for Parrot to underrate the batteries for what they can do. I think they're fairly close to what they predict. Under 20% in normal weather and I'm on my way home. In cool weather I get nervous under 30%, generally stick to short flights.

That auto RTH is a safety feature, I certainly wouldn't test it out any more than I'd test the airbags or seatbelts in my car, because if it can fail ( and what would the point of the test be if it doesn't perhaps fail? ) then it'd be destructive. Leave the failsafe testing to the crash test dummies.

 

[pedrosfia]

I hope you soon hear from Parrot. Remember it has been a lot of holidays within the last to weeks.

So far I have got a case number and they has promise to return within 48 hours, which must be tomorrow if they also have to stay on weekend too. I will assume they send an email tomorrow and ask for my log for that flight that ends 36 meters up in the air with 7% power left on the battery, according to the log. Then I have to see what they say. In any case, my Anafi is grounded until I get a clarification of what happened.

Regards, Leif.

They answer after 48 hours. But they've asked me 5 times to share flight data on app. Did it 15 days ago, and even asked Agustine if I was doing it wrong, and he said I couldn't enable anything else.... 20 days have passed, and I still got nothing... I think I'll send it to the retail store...

 

[Landbo]

They answer after 48 hours. But they've asked me 5 times to share flight data on app. Did it 15 days ago, and even asked Agustine if I was doing it wrong, and he said I couldn't enable anything else.... 20 days have passed, and I still got nothing... I think I'll send it to the retail store...

I think you should write to Parrot again and ask nicely how the evaluation of your flight log goes.

Regards, Leif.

 

[Landbo]

Remember that battery voltage is not linear, there will be a big dip at either end, and a probably a curve in the middle, and it's quite difficult to predict capacity left when discharging without knowing the rate of discharge ( which is a thing in the future - how would it know that you were going to sit still for five minutes idling, then request more power to accelerate and fly back? ).

Cold weather is going to make this worse, this dip will come earlier, but it'll be even less predictable - increased load on the battery will warm it up on the inside of the battery, allowing more current draw, but depleting it faster than if it was warm on it's own from the outside temperature. You can't just rely on temp of battery alone, because the battery will work harder to draw power faster which warms the battery itself. You don't know what the temp is internal to the battery because there is no probe on the inside of the cell, just strapped to the outside, so there is a bit of delay getting the exact temp anyway - if it's cold but you see 11.9 volts, is it cool but low because you're seeing the result of the cold, or is it super warm just now on the inside but the battery is on it's last gasp?

Even if you know the exact variables, outside temp, internal battery temp, constant amp draw, it's difficult to get that last 5-10% exactly predicted where it will drop, especially where we're getting our voltage from the drop of two cells that we've been drawing down from almost full voltage - if they were balanced when we started, they certainly are a bit out of balance now near the end of their capacity, and one will be inevitably trying to make up for the shortcoming of the other.

When you stop drawing current the battery has a chance to recover for a second and you'll start seeing a higher voltage - we've probably all see where a battery in an item is dead, but then you turn the item off and turn it back on and it's working for a few seconds.

Guessing the percentage left is a tradeoff. One solution is for Parrot to underrate the batteries for what they can do. I think they're fairly close to what they predict. Under 20% in normal weather and I'm on my way home. In cool weather I get nervous under 30%, generally stick to short flights.

That auto RTH is a safety feature, I certainly wouldn't test it out any more than I'd test the airbags or seatbelts in my car, because if it can fail ( and what would the point of the test be if it doesn't perhaps fail? ) then it'd be destructive. Leave the failsafe testing to the crash test dummies.View attachment 882

Yes and no, after reading your post several times i mean that you mixing the remaining flight time and the power percentage on the battery.

If we stick to the battery's remaining power as Parrot tells us, then the battery manufacturer should know the curves at the different temperatures and include the safety percentage. It is not the user who has to calculate the things they do not know anyway. It's actually what you pay the smart battery manufacturer an overprice on +80% to do.

Therefore, you must also be able to rely on the copters firmware RTH function to work as intended.

There is no one who has yet said that it is the battery that has shut down. It might as well be a error on Anafi's computer, firmware or hardware when Anafi apparently thought it was landed and could turn off the engines !!!

I measured the voltage over the battery immediately after the crash to 7.21 volts unloaded. It should be possible to run that descent on 36 meters to end width a cell voltage of 3.65 volts without problems.

Regards, Leif.

 

[Jagerbomb52]

Yikes! That's a 3-cell battery You're reading. Since discharging a single lipo cell below 3.0 volts will damage it, you can only discharge the battery to 9 volts minimum. (3 volts per cell).

Both the Anafli and Bebop drones are calibrated to shut down at exactly 9.0 volts to avoid damage to both the battery and the on-board electronics. I'm sure the poor little drone tried it's best to get home before it hit it's low-power threshold.

Remember, the battery "gauge" is nothing but a poor estimation based of an averaging algorithym. Despite the speculation in this thread, it honestly doesn't compensate for temperature, wind etc. Flying below 10% - even an RTH - in the wind on a cold day is a formula for disaster.

No he is reading a two cell battery and that is 3.605 volts per cell, more then enough to get the bird back to home point

 

[AaronB]

I guess the issue here is that the Anafi is a consumer drone - and as such a lot of people will think that an expensive smart battery will protect them from disaster. Those of us who have been in the hobby for a long time realise the enormous number of variables related to battery and flight time and how some are based on future prediction - hence the impossibility of calculating the exact RTH point. I've never flown below 30% unless close to the ground. Drones are really just a flying brick - battery is everything. Yes the batteries from Anafi are expensive - but at least I can claim warranty with a genuine battery and hopefully the battery is made of high quality materials and will last me many years - though probably at reduced flight times.

 

[Landbo]

Yikes! That's a 3-cell battery You're reading. Since discharging a single lipo cell below 3.0 volts will damage it, you can only discharge the battery to 9 volts minimum. (3 volts per cell).

Both the Anafli and Bebop drones are calibrated to shut down at exactly 9.0 volts to avoid damage to both the battery and the on-board electronics. I'm sure the poor little drone tried it's best to get home before it hit it's low-power threshold.

Remember, the battery "gauge" is nothing but a poor estimation based of an averaging algorithym. Despite the speculation in this thread, it honestly doesn't compensate for temperature, wind etc. Flying below 10% - even an RTH - in the wind on a cold day is a formula for disaster.

NO NO NO, Anafi only runs on an S2 Li-Hv battery (2 times Lithium-High voltage cell). Why people suddenly think it's a S3 I don't know. Fully charged, the max voltage per cell is 4.35 and the cut off point should be around 3.0 volts. Make a measure yourself on a battery if you do not think im telling the true.

Regards, Leif.

 

[Kilrah]

He had already corrected himself, read his next post.

LiHV also has a higher minimum voltage, around 3.2V instead of 3.0. So at 3.6 unloaded it's basically completely empty.

 

[Moonfly]

[QUOTE = "zandoli, post: 8688, membro: 54"] 5 gennaio? Volato il 10? [/ CITAZIONE]

It is a good precaution to charge the battery the same day of the flight, at most the previous day.

 

[MustangPhil]

I found this on the Anafi Owners Group on Face
Book that looks like your problem :

Just had my Anafi go crazy when I started a dolly zoom. Half way through it just started going crazy and took off. Full battery and both GPS where green. Before flight I did a compass calibration and it was successful. Last known location is in thick 40 foot trees with 3 feet of snow. No way to find it in there. It might as well be at the bottom of the ocean as I cannot find it. Tried the beeper and heard nothing where it said it should be. Tried to reconnect to it but nothing so I am guessing battery got displaced. Sent off a email to Parrot support with all my info and what happened. Lets see just how they handle this one.

 

[Landbo]

[QUOTE = "zandoli, post: 8688, membro: 54"] 5 gennaio? Volato il 10? [/ CITAZIONE]

It is a good precaution to charge the battery the same day of the flight, at most the previous day.

Dear friend, it is a little difficult to do so when the battery will not take any power before the content has dropped to about 85-90%, do you not think so ?

And at the same time I can tell you that the same battery would not take power the evening before the crash !!!

Regards, Leif.

 

[Landbo]

I found this on the Anafi Owners Group on Face
Book that looks like your problem :

Just had my Anafi go crazy when I started a dolly zoom. Half way through it just started going crazy and took off. Full battery and both GPS where green. Before flight I did a compass calibration and it was successful. Last known location is in thick 40 foot trees with 3 feet of snow. No way to find it in there. It might as well be at the bottom of the ocean as I cannot find it. Tried the beeper and heard nothing where it said it should be. Tried to reconnect to it but nothing so I am guessing battery got displaced. Sent off a email to Parrot support with all my info and what happened. Lets see just how they handle this one.

Sorry but I haven't used Dolly Zoom !!!

You must write the message in the thread that Agustine has startet about his crash: Anafi Just Went Crazy

Regards, Leif.

 

[Liger 1956]

You must write the message in the thread that Agustine has startet about his crash: Anafi Just Went Crazy

Regards, Leif.

It is exactly the same post as Agustine made at the start of his thread. So putting 2 and 2 together they are the same occurrence.

 

[MustangPhil]

Oh ! Sorry I missed that (and wrong thread !!!)