Battery Cell Broken

Humanparody · Feb 16, 2017

I did notice a higher drawdown on that one cell during heavy load (see above pictures). I don't know what is considered "excessive" though.

Cyberpower678 · Feb 16, 2017

adiru said:
That is terrible, I thought these rated for 500?!

They are. My current battery has 34 charges on it.

Cyberpower678 · Feb 16, 2017

Another possibility is that the battery's capacity is severely diminished in one sell, or is unable to deliver the proper current. That would not be reflected in the voltages.

CyberNate · Feb 16, 2017

Cyberpower678 said:
Another possibility is that the battery's capacity is severely diminished in one sell, or is unable to deliver the proper current. That would not be reflected in the voltages.

No, that's not possible. Voltage and current go hand in hand. The voltage will sag if the cell is going bad. The monitoring will be on the cell voltage, not current.

Humanparody · Feb 16, 2017

CyberNate said:
It looks like the battery is ok. .05 volt variance is not much. Pushing the motors to the max in low temperatures is going to test the limits of the battery. I've had a couple over current warnings in sport mode when I'm giving maximum elevator and pitch into the wind. It was 60 degrees at the time. I can imagine at 36F it would be worse.

Regarding DJI, all the warning information will be in your flight log. I don't think you'd have an issue with DJI support; however they may decide that the battery is fine given the circumstances of the warning.

I'm currently charging it to full and am going to take it up and run its through its paces. My previous test was only about 5 minutes and only a few conservative hard drawdowns in case it fell from the sky. It didn't really have much time to show a substantial variation between the cells. Obviously something was bad enough to trigger the warning, I just didn't catch what it was. I need to reproduce the same circumstances as last time as see how they act over a longer flight

Cyberpower678 · Feb 16, 2017

CyberNate said:
No, that's not possible. Voltage and current go hand in hand. The voltage will sag if the cell is going bad. The monitoring will be on the cell voltage, not current.

True, it was just a thought.

Humanparody · Feb 16, 2017

Whelp, it looks like it might have been a one time thing. I just took it from full charge (.02 cell variance) down to low battery warning (.01 cell variance) while flying it hard and it had zero issues. The only thing I can think is that it had been a few days since I had flown that battery and one of the cells may have discharged slightly faster than the others while in storage and I took off with it like that. Lesson learned, always check your cells before takeoff.

Humanparody · Feb 16, 2017

Where/how to I find the error logs?

Cyberpower678 · Feb 16, 2017

Humanparody said:
Where/how to I find the error logs?

The error would be recorded in the flight log of the drone.

Anthony Viscomi · Feb 16, 2017

IMO...If DJI covers the battery under warranty, then why not just send it back for a replacement. Could be fine for another 20 charges, then possibly "crap out" and crash after it's out of warranty. Your initial warning "Battery Cell Broken. Replace Battery" isn't something that most if any of us have ever received.

Humanparody · Feb 16, 2017

Cyberpower678 said:
The error would be recorded in the flight log of the drone.

I'm not seeing anything there as far as warnings. In fact, I can't find any flight log for today whatsoever. I'm assuming that you're referring to the flight log section in the menus where you see high wind warnings and IMU initializations and whatnot? Is there some other location that contains more detailed information about the flight like altitude and positions etc.?

Humanparody · Feb 16, 2017

Anthony Viscomi said:
IMO...If DJI covers the battery under warranty, then why not just send it back for a replacement. Could be fine for another 20 charges, then possibly "crap out" and crash after it's out of warranty. Your initial warning "Battery Cell Broken. Replace Battery" isn't something that most if any of us have ever received.

Do a search for "returning batteries to DJI" and you'll understand my hesitance. It seems like a complete nightmare for everyone who's done it.

Cyberpower678 · Feb 16, 2017

Humanparody said:
I'm not seeing anything there as far as warnings. In fact, I can't find any flight log for today whatsoever. I'm assuming that you're referring to the flight log section in the menus where you see high wind warnings and IMU initializations and whatnot? Is there some other location that contains more detailed information about the flight like altitude and positions etc.?

The drone's black box may have that information. Upload the latest log from the black box into a dropbox.

Humanparody · Feb 16, 2017

Cyberpower678 said:
The drone's black box may have that information. Upload the latest log from the black box into a dropbox.

hieroglyphs....that's what I just read that as

lol

Forgive my ignorance, how do I go about accessing the black box?

Humanparody · Feb 16, 2017

I'm going to take an educated guesstimate and say that I need to hook up the drone to a computer. Let me get on that.

Cyberpower678 · Feb 16, 2017

Humanparody said:
I'm going to take an educated guesstimate and say that I need to hook up the drone to a computer. Let me get on that.

Yes. Good job.

Once you have it connected, you can then open DJI Assistant 2. There should be an option somewhere to let you access the flight logs and it will mount the black box as another drive on the computer. The black box is read only. Grab the one with error, may be multiple files if they first one exceeds 450 MB, or something close, and upload it to dropbox.

Humanparody · Feb 16, 2017

Speaking of hieroglyphs, the black box is in Chinese. Was looking through the detailed flight logs and checking out the voltage/amperage logs for the flight. At one point the amperage skyrocketed during some maneuver. I'd imagine that's when the error occurred. Unfortunately it's not broken down into individual cells so I can't see what exactly happened to throw the error.

Cyberpower678 · Feb 16, 2017

Humanparody said:
Speaking of hieroglyphs, the black box is in Chinese. Was looking through the detailed flight logs and checking out the voltage/amperage logs for the flight. At one point the amperage skyrocketed during some maneuver. I'd imagine that's when the error occurred. Unfortunately it's not broken down into individual cells so I can't see what exactly happened to throw the error.

Upload it.

Anthony Viscomi · Feb 17, 2017

Humanparody said:
Do a search for "returning batteries to DJI" and you'll understand my hesitance. It seems like a complete nightmare for everyone who's done it.

Sending anything back to DJI sucks. You may want to read these posts from over on the Phantom Forum:
Message "Warning - Battery: Cell Broken" in flight - complete shut down

Humanparody · Feb 17, 2017

Cyberpower678 said:
Yes. Good job. Once you have it connected, you can then open DJI Assistant 2. There should be an option somewhere to let you access the flight logs and it will mount the black box as another drive on the computer. The black box is read only. Grab the one with error, may be multiple files if they first one exceeds 450 MB, or something close, and upload it to dropbox.