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Re: Evo II Pro falling from the skies?!!!??

Samysys

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Hi, I thought I was the only one experienced this until I read the post of DocFlyboy89.

My hypothesis is there are something wrong with the chips/firmware of the battery. I will explain.

There are signs that you can spot and avoid this happen to you. See below.

I had experienced three “crash” and successfully reconstruct a controlled “crash”. I managed to recover the drone every time (lucky me). All incident happened just like DocFlyboy89 described. I will provide more details.

Background
My EVO II Pro has over 10 hrs of flight time and in mint condition. All software was regularly updated. I use a smart controller. No modification was made and I like that drone.

Here is the gist of the crash:

First incident:
I was flying over my EVO II Pro in a harbor area in a sunny day. Temperature was hot (over 30C) but dry. The drone functioned well with my first battery (about 25 minute of flight time, before reaching the battery capacity) (therefore eliminated mechanical failure of the drone/controller).

In the second flight with the problematic battery, I flied at around 120m height. When I reach to about 800m far (may just take 2-3 min), it suddenly kicked in the return to home function. In the first instance, I thought it was due to radio interference (Hong Kong urban area is known to have strong interference and the video feed was not perfect on that day). I had checked and maintain constant attention to battery level so vividly recalled that it shows having 26 min of flight time the second before everything happened.

A few seconds later, the controller further showed that the battery at 0% and started forced descend and landing. I managed to land it on a dam of a typhoon shelter. I then took a boat and went to search and recovered the drone after 3 hours. It has some scratch but fine. The battery indicator showed no battery (blinking one light).

A controlled flight was conducted with the same battery. After fully recharge, it works normal so the battery was released back to work (Big mistake!)

Second incident
Again, I flied near a beach. This time about 100m height and up to 1km distance. Same happened. After flied for around 5 min, the battery level showed dropped to zero and forced landing. In that a few second, I checked the status of the battery and confirmed it was not overheated (around 40C at that moment).

As there are trees nearby, the connection soon disconnected. I immediately ran towards the landing area. It took me about 15 min to search, study map and eventually arrive the vicinity. To my surprise, I found the controller had already reconnected to the drone. It was still hovering over a tree top all the way. I managed to control it for a peaceful landing.

The recording function of the drone was not stopped so I can review back and found that it was hovering all the time until I took back control. The battery (Battery A) was hold up for further analysis, more on that later.

Third incident
This time, I flied over a flatland. 120m height, 300m away, after 5 minutes of flight, everything happened again. I was so experienced by then, I controlled it land on a bicycle track and recovered it just after 1-2 minutes…. Practices make perfect. That battery was marked Battery B.

My battery management
I have 6 batteries in rotation. Defaulted to discharge to 70% if not used for 7 days. They sit in an air conditioned room when am not using. They are in mint condition. Up to now, I have charged them 8-10 times. I bought 4 (including battery A) in the first instance, and bought last 2 (including battery B) from another dealer. They should belong to different manufacturing batches but I have to confirm it later.

Controlled crash

With the help of my friend, I conducted several tests.

I used my drones and re-tested battery B. After full charge, the first flight was perfectly normal (cunning battery). I then full charge it again and did the second flight. Haha~ here was the problem and the crash was perfectly reconstructed. I have put a dumbbell below the drone so that the safety sensor cannot auto land it. I have ample time to look for problems. Photo of the controller screen attached.

As you can see, there are problem with the battery. It showed 0% whilst the voltage was normal (that voltage equals to about 60-70% of battery). The drone was able to fly solid 30 min (in stationary position).

Battery A was tested by my friend with another Evo II Pro and the same happened. The drone was landed immediately (without exhausting despite the controller showed it has 0%). It was not charged and left overnight. The next morning, it was back alive and showing 70% of battery (cunning! reading by both battery indicator and reading from controller)

Battery A was dissected and found all connection and soldering solid. No burn smell or charred marks was found on it. Individually test the voltage of each battery component was at normal range (i.e. over 3V for each cell in full charge). The dissected battery was resembled and still can fly. But problem persisted.

Another abnormally is that both Battery A and Battery B showed exceptional high charge cycle. They showed over 30 charging cycle. As I used my batteries in rotation and share the load on them, the reading should not exceed 15 (my other battery was only cycled 8-10 times). This is a very good sign for you to check if the battery has problem.

Flight log:
My friend had studied the flight log of his controlled flight of Battery A. Match everything we observed.
I have not studied mine. I don’t think it’s necessary but I still have them.

My thoughts so far now:

  1. Something wrong with the battery, most likely because of the firmware.
  2. There are still power in the battery, just the program of the drone do not think so thus the problem
  3. You cannot spot the problem in a new battery, it only appears after used for several times.
  4. Only known indicator is if the battery showed abnormal high number of re-charge cycle.
  5. The problem is on the product and the fault rest with the manufacturer, not user.
  6. Cannot identify the scope of problem yet because limited information


Last words:
If you found your battery behaving as I described, DON’T throw it away. I run a drone training school and these batteries are perfect for crash landing response training. Pls contact me ([email protected]) and I will make good use of them.

Every cloud has a silver lining, right?
 

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Wild guess but thinking aloud and I will continue to think this through: can you test the suspect batteries for impedance? When charged or just off the charger they may appear to be in good health voltage wise....but internally, they may have built up a higher than desirable internal resistance that most batteries will do over time...some prematurely.
 
Next attempt to blame shift to Autel, it will read better if you change the location to somewhere with airspace not critical infrastructure controlled by PRC military.

How many troll personas can one troll manage with troll management persona management software nowadays? Last I heard it was 1000, but that number has long since been eclipsed by the sum of the unique trolls to spam this board with click-bait titles that don't match reality
 
Hi, I thought I was the only one experienced this until I read the post of DocFlyboy89.

My hypothesis is there are something wrong with the chips/firmware of the battery. I will explain.

There are signs that you can spot and avoid this happen to you. See below.

I had experienced three “crash” and successfully reconstruct a controlled “crash”. I managed to recover the drone every time (lucky me). All incident happened just like DocFlyboy89 described. I will provide more details.

Background
My EVO II Pro has over 10 hrs of flight time and in mint condition. All software was regularly updated. I use a smart controller. No modification was made and I like that drone.

Here is the gist of the crash:

First incident:
I was flying over my EVO II Pro in a harbor area in a sunny day. Temperature was hot (over 30C) but dry. The drone functioned well with my first battery (about 25 minute of flight time, before reaching the battery capacity) (therefore eliminated mechanical failure of the drone/controller).

In the second flight with the problematic battery, I flied at around 120m height. When I reach to about 800m far (may just take 2-3 min), it suddenly kicked in the return to home function. In the first instance, I thought it was due to radio interference (Hong Kong urban area is known to have strong interference and the video feed was not perfect on that day). I had checked and maintain constant attention to battery level so vividly recalled that it shows having 26 min of flight time the second before everything happened.

A few seconds later, the controller further showed that the battery at 0% and started forced descend and landing. I managed to land it on a dam of a typhoon shelter. I then took a boat and went to search and recovered the drone after 3 hours. It has some scratch but fine. The battery indicator showed no battery (blinking one light).

A controlled flight was conducted with the same battery. After fully recharge, it works normal so the battery was released back to work (Big mistake!)

Second incident
Again, I flied near a beach. This time about 100m height and up to 1km distance. Same happened. After flied for around 5 min, the battery level showed dropped to zero and forced landing. In that a few second, I checked the status of the battery and confirmed it was not overheated (around 40C at that moment).

As there are trees nearby, the connection soon disconnected. I immediately ran towards the landing area. It took me about 15 min to search, study map and eventually arrive the vicinity. To my surprise, I found the controller had already reconnected to the drone. It was still hovering over a tree top all the way. I managed to control it for a peaceful landing.

The recording function of the drone was not stopped so I can review back and found that it was hovering all the time until I took back control. The battery (Battery A) was hold up for further analysis, more on that later.

Third incident
This time, I flied over a flatland. 120m height, 300m away, after 5 minutes of flight, everything happened again. I was so experienced by then, I controlled it land on a bicycle track and recovered it just after 1-2 minutes…. Practices make perfect. That battery was marked Battery B.

My battery management
I have 6 batteries in rotation. Defaulted to discharge to 70% if not used for 7 days. They sit in an air conditioned room when am not using. They are in mint condition. Up to now, I have charged them 8-10 times. I bought 4 (including battery A) in the first instance, and bought last 2 (including battery B) from another dealer. They should belong to different manufacturing batches but I have to confirm it later.

Controlled crash

With the help of my friend, I conducted several tests.

I used my drones and re-tested battery B. After full charge, the first flight was perfectly normal (cunning battery). I then full charge it again and did the second flight. Haha~ here was the problem and the crash was perfectly reconstructed. I have put a dumbbell below the drone so that the safety sensor cannot auto land it. I have ample time to look for problems. Photo of the controller screen attached.

As you can see, there are problem with the battery. It showed 0% whilst the voltage was normal (that voltage equals to about 60-70% of battery). The drone was able to fly solid 30 min (in stationary position).

Battery A was tested by my friend with another Evo II Pro and the same happened. The drone was landed immediately (without exhausting despite the controller showed it has 0%). It was not charged and left overnight. The next morning, it was back alive and showing 70% of battery (cunning! reading by both battery indicator and reading from controller)

Battery A was dissected and found all connection and soldering solid. No burn smell or charred marks was found on it. Individually test the voltage of each battery component was at normal range (i.e. over 3V for each cell in full charge). The dissected battery was resembled and still can fly. But problem persisted.

Another abnormally is that both Battery A and Battery B showed exceptional high charge cycle. They showed over 30 charging cycle. As I used my batteries in rotation and share the load on them, the reading should not exceed 15 (my other battery was only cycled 8-10 times). This is a very good sign for you to check if the battery has problem.

Flight log:
My friend had studied the flight log of his controlled flight of Battery A. Match everything we observed.
I have not studied mine. I don’t think it’s necessary but I still have them.

My thoughts so far now:

  1. Something wrong with the battery, most likely because of the firmware.
  2. There are still power in the battery, just the program of the drone do not think so thus the problem
  3. You cannot spot the problem in a new battery, it only appears after used for several times.
  4. Only known indicator is if the battery showed abnormal high number of re-charge cycle.
  5. The problem is on the product and the fault rest with the manufacturer, not user.
  6. Cannot identify the scope of problem yet because limited information


Last words:
If you found your battery behaving as I described, DON’T throw it away. I run a drone training school and these batteries are perfect for crash landing response training. Pls contact me ([email protected]) and I will make good use of them.

Every cloud has a silver lining, right?
Thank you for your very informative and much appreciated post! This is the exactly all that I intended to do from the beginning. While I don’t have as much experience as you as it appears (you run a slight school), but I have been 107 certified and have been flying small UAV drones for several years and admittedly I have had pilot error issues, but my most recent issue with my E2P6k was identical to yours as far as the event. Unfortunately I was never able to find my drone but my flight logs confirmed the exact type of situation. But I could not perform an “autopsy“ because I could not recover my lost drone nor my lost battery.

I also remain appreciative of Autel, Since they did offer me a 35% discount and replacing my Evo II pro, but I still am very nervous about flying this unit or my other thermal enterprise class 640T drone for the obvious reasons. They both use the same battery system, firmware and software!

Do I feel Autel should have replaced my entire lost drone system…… Yes!

Am I appreciative of the discount they offered… Of course!

But they are not offering answers or even opening up Q&A/discussions – discourse from their devoted customers as well as other experts and end users to try to solve this problem but also to recognize it as a real problem.

Finally, I did also purchase a nano plus that from out of the box after confirmed up-to-date firmware, appropriate charging, etc. etc. etc. and after my very first launch and hover the unit fluid radically on its own just literally a few feet away from me and only 1 m off the ground flying into the side of my house 30 yards away. Perhaps that’s a different thread or an additional issue on the nano plus thread!?!? LOL

But the battery issue/question/problem absolutely needs addressing and frankly owners that have suffered this at the least should be evaluated, compensated for any loss and if ultimately the problem should and can’t be solved. Thank you for your post!
 
According to this anecdotal telling, there are actually 2 indicators thar you have a suspect battery. 1. The stated "over counted cycles" -which can only be tracked manually, by this account, and 2. Battery info on the controller shows useable capacity per voltage, yet 0% available. That is quite obviously an "indication" of some malfunction, incorrect system reporting, and/or battery/system firmware bug. I would like to see the firmware versions, including battery to be sure the battery FW version is correctly matched and not out of step with the aircraft or controller. Color me paranoid, but I thing posting things like this, even with the best intentions could be regrettable, if the Evo 2 Pro were to cause property damage or injury, since it basically admits continually flying with known failing batteries in non-controlled environments. It may be an unpopulated area, but doesn't sound like privately owned and controlled land under these "test" crash recoveries. Just sayin'.
 
Hi, I thought I was the only one experienced this until I read the post of DocFlyboy89.

My hypothesis is there are something wrong with the chips/firmware of the battery. I will explain.

There are signs that you can spot and avoid this happen to you. See below.

I had experienced three “crash” and successfully reconstruct a controlled “crash”. I managed to recover the drone every time (lucky me). All incident happened just like DocFlyboy89 described. I will provide more details.

Background
My EVO II Pro has over 10 hrs of flight time and in mint condition. All software was regularly updated. I use a smart controller. No modification was made and I like that drone.

Here is the gist of the crash:

First incident:
I was flying over my EVO II Pro in a harbor area in a sunny day. Temperature was hot (over 30C) but dry. The drone functioned well with my first battery (about 25 minute of flight time, before reaching the battery capacity) (therefore eliminated mechanical failure of the drone/controller).

In the second flight with the problematic battery, I flied at around 120m height. When I reach to about 800m far (may just take 2-3 min), it suddenly kicked in the return to home function. In the first instance, I thought it was due to radio interference (Hong Kong urban area is known to have strong interference and the video feed was not perfect on that day). I had checked and maintain constant attention to battery level so vividly recalled that it shows having 26 min of flight time the second before everything happened.

A few seconds later, the controller further showed that the battery at 0% and started forced descend and landing. I managed to land it on a dam of a typhoon shelter. I then took a boat and went to search and recovered the drone after 3 hours. It has some scratch but fine. The battery indicator showed no battery (blinking one light).

A controlled flight was conducted with the same battery. After fully recharge, it works normal so the battery was released back to work (Big mistake!)

Second incident
Again, I flied near a beach. This time about 100m height and up to 1km distance. Same happened. After flied for around 5 min, the battery level showed dropped to zero and forced landing. In that a few second, I checked the status of the battery and confirmed it was not overheated (around 40C at that moment).

As there are trees nearby, the connection soon disconnected. I immediately ran towards the landing area. It took me about 15 min to search, study map and eventually arrive the vicinity. To my surprise, I found the controller had already reconnected to the drone. It was still hovering over a tree top all the way. I managed to control it for a peaceful landing.

The recording function of the drone was not stopped so I can review back and found that it was hovering all the time until I took back control. The battery (Battery A) was hold up for further analysis, more on that later.

Third incident
This time, I flied over a flatland. 120m height, 300m away, after 5 minutes of flight, everything happened again. I was so experienced by then, I controlled it land on a bicycle track and recovered it just after 1-2 minutes…. Practices make perfect. That battery was marked Battery B.

My battery management
I have 6 batteries in rotation. Defaulted to discharge to 70% if not used for 7 days. They sit in an air conditioned room when am not using. They are in mint condition. Up to now, I have charged them 8-10 times. I bought 4 (including battery A) in the first instance, and bought last 2 (including battery B) from another dealer. They should belong to different manufacturing batches but I have to confirm it later.

Controlled crash

With the help of my friend, I conducted several tests.

I used my drones and re-tested battery B. After full charge, the first flight was perfectly normal (cunning battery). I then full charge it again and did the second flight. Haha~ here was the problem and the crash was perfectly reconstructed. I have put a dumbbell below the drone so that the safety sensor cannot auto land it. I have ample time to look for problems. Photo of the controller screen attached.

As you can see, there are problem with the battery. It showed 0% whilst the voltage was normal (that voltage equals to about 60-70% of battery). The drone was able to fly solid 30 min (in stationary position).

Battery A was tested by my friend with another Evo II Pro and the same happened. The drone was landed immediately (without exhausting despite the controller showed it has 0%). It was not charged and left overnight. The next morning, it was back alive and showing 70% of battery (cunning! reading by both battery indicator and reading from controller)

Battery A was dissected and found all connection and soldering solid. No burn smell or charred marks was found on it. Individually test the voltage of each battery component was at normal range (i.e. over 3V for each cell in full charge). The dissected battery was resembled and still can fly. But problem persisted.

Another abnormally is that both Battery A and Battery B showed exceptional high charge cycle. They showed over 30 charging cycle. As I used my batteries in rotation and share the load on them, the reading should not exceed 15 (my other battery was only cycled 8-10 times). This is a very good sign for you to check if the battery has problem.

Flight log:
My friend had studied the flight log of his controlled flight of Battery A. Match everything we observed.
I have not studied mine. I don’t think it’s necessary but I still have them.

My thoughts so far now:

  1. Something wrong with the battery, most likely because of the firmware.
  2. There are still power in the battery, just the program of the drone do not think so thus the problem
  3. You cannot spot the problem in a new battery, it only appears after used for several times.
  4. Only known indicator is if the battery showed abnormal high number of re-charge cycle.
  5. The problem is on the product and the fault rest with the manufacturer, not user.
  6. Cannot identify the scope of problem yet because limited information


Last words:
If you found your battery behaving as I described, DON’T throw it away. I run a drone training school and these batteries are perfect for crash landing response training. Pls contact me ([email protected]) and I will make good use of them.

Every cloud has a silver lining, right?
Hi Samysys,
I have read your recollection of the incidents and looked at your photo of the screen shot. You have not mentioned the temp of the battery, but I noted it on the screen shot (47.9). This looks like an over heated battery, as the manual states " exposure to temps below -10°C and above 40 ° C or it can reduce the life of the batteries. I am a licensed UAV PILOT in Australia and our business does roof and building Inspections, our procedure manual requires us to log the temp of the batteries and motors after every flight with and I R thermometer ( not the one on the controler, for accuracy purposes). The Autel manual has given the safety guide line for one reason and that is to not HAVE FAILURES LIKE THIS ONE. Afraid I class it as PILOT in CHANGE ERROR and in Australia that is a very big NO ,NO.
These batteries are the life blood of your craft and you are lucky to get it back and no PUBLIC were injured. RULES must be very different in HONG KONG , especially that you are running a UAV SCHOOL.?? Please fly Safe and obey the rules. I would say that you have had a battery malfunction due to excessive heat build up and reduced the battery life.
Good information on li-popular batteries can be found at batteryuniversity.com this is worth reading about our batteries that are our live blood of our craft. KEEP FLYING ON THE GREEN SIDE OF THE GRASS. John Hennessy.Australia.


According to this anecdotal telling, there are actually 2 indicators thar you have a suspect battery. 1. The stated "over counted cycles" -which can only be tracked manually, by this account, and 2. Battery info on the controller shows useable capacity per voltage, yet 0% available. That is quite obviously an "indication" of some malfunction, incorrect system reporting, and/or battery/system firmware bug. I would like to see the firmware versions, including battery to be sure the battery FW version is correctly matched and not out of step with the aircraft or controller. Color me paranoid, but I thing posting things like this, even with the best intentions could be regrettable, if the Evo 2 Pro were to cause property damage or injury, since it basically admits continually flying with known failing batteries in non-controlled environments. It may be an unpopulated area, but doesn't sound like privately owned and controlled land under these "test" crash recoveries. Just sayin,k
 
Next attempt to blame shift to Autel, it will read better if you change the location to somewhere with airspace not critical infrastructure controlled by PRC military.

How many troll personas can one troll manage with troll management persona management software nowadays? Last I heard it was 1000, but that number has long since been eclipsed by the sum of the unique trolls to spam this board with click-bait titles that don't match reality
Hi~ in case you are really trying to reason out the problem, the test flight was conducted indoor without much outside interferrence.
 
Hi Samysys,
I have read your recollection of the incidents and looked at your photo of the screen shot. You have not mentioned the temp of the battery, but I noted it on the screen shot (47.9). This looks like an over heated battery, as the manual states " exposure to temps below -10°C and above 40 ° C or it can reduce the life of the batteries. I am a licensed UAV PILOT in Australia and our business does roof and building Inspections, our procedure manual requires us to log the temp of the batteries and motors after every flight with and I R thermometer ( not the one on the controler, for accuracy purposes). The Autel manual has given the safety guide line for one reason and that is to not HAVE FAILURES LIKE THIS ONE. Afraid I class it as PILOT in CHANGE ERROR and in Australia that is a very big NO ,NO.
These batteries are the life blood of your craft and you are lucky to get it back and no PUBLIC were injured. RULES must be very different in HONG KONG , especially that you are running a UAV SCHOOL.?? Please fly Safe and obey the rules. I would say that you have had a battery malfunction due to excessive heat build up and reduced the battery life.
Good information on li-popular batteries can be found at batteryuniversity.com this is worth reading about our batteries that are our live blood of our craft. KEEP FLYING ON THE GREEN SIDE OF THE GRASS. John Hennessy.Australia.
John,

From your comment, I believe you are a true expert. Indeed, battery is the life line of the drone.

For the indoor test flight, it was conducted in a well controlled room at 23-24C (room temperature). For the temperature of the battery, it gradually raised and plateau at 55C. I observe that the rise of temperature was consistent with my other batteries (that works fine and normal). I allow it to continue the flight so that I can observe and try to identify the problem.

For my second crash, I had checked the battery temperature and am very sure it was 37-38C at the time malfunction happened. My point is battery temperature seems to have nothing to do with the crash.

I also checked the Autel Manual. I think you are correct that the operation temperature suggested was between -10 to 40C. But I think it refers to the external temperature, i.e. air temperature. Lithium battery always generate heat during charge/discharge. I think the manufacturer had taken this into consideration. When I fly with DJI, the battery temperature also raises to similar temperature. I would agree that anything over 60C is a no go and very likely have something wrong there.

Looking forward for your views~

P.S. I think Aussie has a very good UAV pilot system and training. I have several good reference books based on CASA requirement. Always useful to read and refresh myself.
 
Mine recently dropped from the sky too. It is an Evo II V1 6k.

Mine has pulled the same low battery stunt a couple of times as well. Specifically, it did so twice on the same outing--I took flight while back country skiing. I had not topped off the batteries, they had lapsed into storage mode. We were a couple of hours from the truck, so everything was cold. It took off as normal, got a few hundred feet away, and suddenly it went into emergency landing mode. As I was flying uphill at the time I was able to navigate back down to where I was and land safely. I tried again with a different battery, thinking it was an anomaly related to the battery, and had an identical result with the next battery. I've had no issues with those batteries or others since, including flying in the exact same conditions with the exception of the batteries being topped of prior to flight.

But the other day I went to fly and it dropped back onto the road after taking off from about 10-15' up. It dropped like the power was disconnected, like a rock, and perished there. It might have been a suicide attempt, I can't be sure. The gimbal is broken, it will pivot right/left, side to side, but the up/down pivot is clearly broken. When I manually level it the drone will fly but there is no picture. I've only flown it at low level, up and down for testing--I'm keeping it on suicide watch for now.

I've contacted a couple of resellers and Autel and the advice is about the same. Autel wants to service it but I see little incentive. They will charge me to fix it but will not warranty it or allow me to purchase their protection plan. I'm loath to spend $800-$1k to have it repaired when it might try to kill itself at any moment with no recourse.

I'd love to know why it dropped as it did. The two test flights since were with the same battery, I've not even removed it. It was powered off as I recall when I retrieved it but it powers right up. The shop I bought it from said it was due to my attempt to lift off from the bed cover of my pickup but I've done that before. After it would not initialize I moved it to an icy patch on the gravel road, 15' from the truck, and then it was "ready to fly" after only a few seconds. He was certain this was the cause due to the truck upsetting the compass. I suggested that if the compass was upset it was probably due to the power lines 30' away but he said that wouldn't cause an issue. Now that I reviewed the manual it is pretty clear that I shouldn't fly it next to a power line--is this what caused the failure??
 

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