I have two Evo 2 Pro batteries that have a bad cell. Ironically both batteries were put into service on the exact same date. Battery number 1 has been discharged 91 times, Battery number 2 has been discharged 98 times. Serial numbers for these are B54820133812 and B54820195425... Anyone else have this same problem? After liftoff, both batteries are at 100% charge but about one minute into the flight, they give an error message and the percentage goes to below 15% and the craft immediately lands. Does Autel take responsibility for bad batteries?
Bad Batteries
- Thread starter Isky
- Start date
You will have to contact Autel and try to get replacements, The warranty allegedly is for 200 cycles but good luck getting it honored.
Your batteries aren't actually bad. What is happening is a voltage balancing issue between the individual cells in the battery pack. If you can completely drain your batteries and then recharge them it might solve the issue. But just understand that there is a circuit board in these batteries that strives to have the voltages in each cell be exactly the same within a few tenths of a volt range. When one cell is outside that range, the entire battery pack reports as "bad". But what has to happen is a rebalancing of all the cells to within the expected range.
The trouble is it might not just be a small difference. If one cell really is bad, there is nothing that can be done. If, OTOH, it is off by just a volt or two, rebalancing will sometimes fix it.
The trouble is it might not just be a small difference. If one cell really is bad, there is nothing that can be done. If, OTOH, it is off by just a volt or two, rebalancing will sometimes fix it.
Waldo Pepper
Well-Known Member
- Joined
- Nov 29, 2019
- Messages
- 436
- Reaction score
- 363
- Age
- 64
That happened today on my third flight, the third battery during flight give a message of (damaged battery). Checked the battery levels and one cell was lower compared with the other cells. Hit RTH button and it wouldn’t work, manually flew it back.
For some reason, this unbalanced battery caused RTH feature not to work. Strange, I’ll follow moodmans advice see if this corrects the problem. Battery has under 80 cycles, maybe can get it correctly balanced with moodmans information. I’ll share if it bounces back, hopefully it does.
The weaker cell was only off by two tenths volt, that was enough to trigger it unsafe as a damaged battery.
For some reason, this unbalanced battery caused RTH feature not to work. Strange, I’ll follow moodmans advice see if this corrects the problem. Battery has under 80 cycles, maybe can get it correctly balanced with moodmans information. I’ll share if it bounces back, hopefully it does.
The weaker cell was only off by two tenths volt, that was enough to trigger it unsafe as a damaged battery.
What ever the issue is with these batteries, it is not singularly to the battery itself. Not to say it could not happen. In my case, it was two batteries that were previously fine, without notice or any sign there was a problem both failed on the same day at the same time. It is something that is triggering them to go down. I have been looking hard at the DJI Air 2 preparing for the day none of my Autel junk works any longer. Strange the Air 2 looks very similar to my evo 1 and Autel has washed their hands of it. I wonder if they just sold the rights and tech to DJI and they picked it up after a little tummy tuck. Bigger than their mini and smaller than the Starship Enterprise. Not like they didn't need an in between. No, they wouldn't do that would they?
Waldo Pepper
Well-Known Member
- Joined
- Nov 29, 2019
- Messages
- 436
- Reaction score
- 363
- Age
- 64
I hope the Evo 2 batteries bounce back for you, maybe you’re on to something and both were triggered for same reason.
I had an Air 2, nice quad good range. Air 2S is even better, probably better than Mavic 2 Pro. I give a good friend of mine the Air 2 for his children, kept the Mavic 2 Pro which is still a good quad. In regards to one of my Evo 2 batteries, after the alert (damaged battery) during the flight it had one cell with less voltage. Recharged the battery, now it appears to be okay all cells are equal on voltage. Haven’t flown it yet with this battery, in which I will soon once it stops raining. Hopefully, it’s okay and maybe just needed to be balanced.
If you do spring for an Air 2, get the Air 2S model it’s worth the extra $$$ over original Air 2.
Good luck!
GeoDrone SRL
Well-Known Member
- Joined
- Aug 18, 2021
- Messages
- 475
- Reaction score
- 273
- Age
- 47
Had this issue with brand new one, at the 2nd cycle from 99% showed at take-off in 4 minutes was landing in forced RTH with 8%.
The balance between cells was fine, difference only of 0.04 Volts.
I have re-writen the firmware using BIN on MicroSD, discharged it on drone until 2%, then recharge it at original charger...
Now is at 7th cycle, no problems anymore, rock solid.
Strange thing was at reading the log...seems that the battery showed 100% for drone app, showed full LED (100%) when pressing the button, but in reality was under 35% according to LOG. I remember that was not charged that week at all, so the low "juice" was correct, but all readings were not. The firmware fixed it, as seems that now is correctly identifying the capacity.
So...another thing we should pay attention: Charging batteries right before flight, in order not to have a misreading then a forced RTH.
The balance between cells was fine, difference only of 0.04 Volts.
I have re-writen the firmware using BIN on MicroSD, discharged it on drone until 2%, then recharge it at original charger...
Now is at 7th cycle, no problems anymore, rock solid.
Strange thing was at reading the log...seems that the battery showed 100% for drone app, showed full LED (100%) when pressing the button, but in reality was under 35% according to LOG. I remember that was not charged that week at all, so the low "juice" was correct, but all readings were not. The firmware fixed it, as seems that now is correctly identifying the capacity.
So...another thing we should pay attention: Charging batteries right before flight, in order not to have a misreading then a forced RTH.
Ungava
Active Member
- Joined
- Mar 23, 2020
- Messages
- 31
- Reaction score
- 17
- Age
- 75
I too had an EVO 2 PRO battery failure a couple days ago. I was at 20% and was preparing for a landing. At 15%, the warning signals came on and the battery registered 0% and the drone made a quick hard landing. The next day I charged to battery to 100% and did an indoor houver 3' off the carpet. At 15%, the rotors quit cold and the drone dropped. I was watching the voltage in the 3 cells and saw the center cell flicker and the light went out. Then the craft fell to the carpet.I tried to contact Autel but they are not answering their phones. Email only.. I have 26 cycles on the battery. I am awaiting a response from Autel.
GeoDrone SRL
Well-Known Member
- Joined
- Aug 18, 2021
- Messages
- 475
- Reaction score
- 273
- Age
- 47
Re-write the firmware, will also re-write the battery FW. After this, try again...monitor your battery in air by checking the Voltage from each cell...if you have one cell unbalanced, in order to prevent a fire, will make an auto land or just cut power. If your cells are balanced and don't have a big difference in V, was just about the miss-reading of cells power, corrected by rewritten firmware.
I had that battery with problems monitored for 3 flights, no more errors, all was working perfectly after I have written it's firmware again (use BIN on microsd card).
This is an excellent suggestion. But there is one other possibility if this doesn't work. There is a possibility that there is an internal short in one of the cells OR the circuitry has a loose connection that causes a spike in the electrical signal that gets interpreted as a bad cell. The loose connection could be caused also by a bad component in the circuit board of the battery.
It's really hard to tell what it really is, but the firmware fix mentioned above would be the first thing I would try. Please report back here so we know if it works for you. Repeat your indoor carpet experiment with the firmware fix idea and let us know please.
Freezing the battery did nothing... I recharged and flew and the battery percentage was 99% when I took off and less than one minute later, it showed 0% and the aircraft immediately landed. I knew the history of the battery and didnt fly far away but if I had, I would have had to land on my customers property and then go try to find the drone hoping no one took it or ran it over with a vehicle... These batteries have one bad cell and should be replaced by Autel., period!
Ungava
Active Member
- Joined
- Mar 23, 2020
- Messages
- 31
- Reaction score
- 17
- Age
- 75
Great suggestion and I will do that today. I did notice on my carpet test that the V was about the same on the 1st & 3rd cells and lower on the 2nd. I cannot remember exactly the difference but I will make notes today at 10% intervals. FYI, it was -6C or about 20F when this occurred. Should not be a problem but it was the first time I flew at this temperature. The battery was a normal warm when I pulled it from the drone. I put in another battery and flew 200M back and forth on the country road I was parked on until the battery reached 5% and there were no issues. Makes me believe the issue is isolated to the battery. also FYI, this last test flight lasted 32m40s which is the longest flight I have had with a drone. Beat the P4PV2.0 which was 29m32s under warm ideal summer conditions. I will keep everyone informed. Thanks for the help. Les
Ungava
Active Member
- Joined
- Mar 23, 2020
- Messages
- 31
- Reaction score
- 17
- Age
- 75
Ungava
Active Member
- Joined
- Mar 23, 2020
- Messages
- 31
- Reaction score
- 17
- Age
- 75
BIN stands for binary. It is a system level file that can only be read from when you put it onto a micro sd card. Then, when it boots up it sees the bin file and executes it. In this case, it executes a firmware update.
Similar threads
