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