Battery query: How big or small a bulge before we stop using an MP battery?

[mnis]

Hi everyone! It’s been a while since we were on this thread for this battery issue. I have recently used the said battery a couple of times and the”bulge” remained the same.
However, I noticed that it seemed to get hotter more quickly than my other battery.
If I remember correctly, it reached something like 47-degrees after less than 50% flight time (not very sure of this figure but definitely hotter to the touch).

What is the allowable maximum temp?

Have you noticed the temperature difference between the suspect and an obviously good battery under the same conditions?

It is generally said that the lithium in the battery reaches a critical temperature above 60 degrees Celsius. I always worried about my batteries because they felt extremely hot immediately after flying, but nothing ever happened.

So if you can answer my question with YES, then you do not have to dispose of this battery hastily. As long as the battery shows no visual change, there is no reason to worry about a sudden explosion or fire.

Against the uneasy feeling:
Stop using the battery to fly. You could still use the battery safely on the ground to perform updates, make settings in DJI Go, or charge USB devices if the adapter is present.

According to your previous statements, it could not be determined with certainty that there was actually a problem. Now you say that the (only tangible) "bulge" has not changed. There is no need to panic. The battery will continue to behave normally unless high demands (flying) are made.

Only under extreme load would a weakened or damaged battery swell until it bursts. Provided the storage and charging area is located in a specially protected environment, I would not worry more than with all the other of my batteries.

Or sell the battery on eBay as a defective item. You'll be surprised how many interested hobbyists there are. Then get yourself a fresh battery so you can fly with less worry again.

 

[Balko]

Have you noticed the temperature difference between the suspect and an obviously good battery under the same conditions?

It is generally said that the lithium in the battery reaches a critical temperature above 60 degrees Celsius. I always worried about my batteries because they felt extremely hot immediately after flying, but nothing ever happened.

So if you can answer my question with YES, then you do not have to dispose of this battery hastily. As long as the battery shows no visual change, there is no reason to worry about a sudden explosion or fire.

Against the uneasy feeling:
Stop using the battery to fly. You could still use the battery safely on the ground to perform updates, make settings in DJI Go, or charge USB devices if the adapter is present.

According to your previous statements, it could not be determined with certainty that there was actually a problem. Now you say that the (only tangible) "bulge" has not changed. There is no need to panic. The battery will continue to behave normally unless high demands (flying) are made.

Only under extreme load would a weakened or damaged battery swell until it bursts. Provided the storage and charging area is located in a specially protected environment, I would not worry more than with all the other of my batteries.

Or sell the battery on eBay as a defective item. You'll be surprised how many interested hobbyists there are. Then get yourself a fresh battery so you can fly with less worry again.

Thank you again mnis for dropping off a reply. I will fly the Mavic one of these days and take note of the temperatures of the battery with the bulge with that of a normal one.
Thank you again.

 

[Shaughan]

Very good information, thanks

 

[Irvine]

I would treat a battery that’s swelling, or heating up differently, seriously. It’s a hint that all is not well. The consequences can be extreme, with an intense fire a district possibility. That happens all to frequently with cell phone batteries.

Swelling is an indication that the protective membrane has been breached, exposing various battery chemicals to ambient moisture. That’s where the bad stuff begins.

Swelling in a drone battery could manifistate itself by having the battery abruptly come loose from its clamps, or the battery losing voltage in-flight.

Do the conservative sensible thing and discard the thing. Why take a chance?

Yes good idea don't use the battery I'd rather lose a battery than the drone. Owning a mavic platinum... spark also a Hubsan H501ss H501a one of the hubsan battery started to swell I immediately through it out. Play safe OK. Regards Irvine Portsmouth UK

 

[mnis]

Guys, this is a suspicious but not yet proven swollen battery!

It's good to be careful and think about what might happen. But just out of some fears, we can immediately throw all our batteries overboard.

It is good to know what can happen, but we should always act calmly and judiciously.

I write about how I handle things, and I think @Balko understands it that way. Gather opinions and then make your own decisions.

Especially with the battery issue, there are so many different views, since it is difficult to do the right thing. So YES, I understand all your concerns. And with continuing doubts it is better to retire this suspicious battery...

 

[Balko]

Guys, this is a suspicious but not yet proven swollen battery!

It's good to be careful and think about what might happen. But just out of some fears, we can immediately throw all our batteries overboard.

It is good to know what can happen, but we should always act calmly and judiciously.

I write about how I handle things, and I think @Balko understands it that way. Gather opinions and then make your own decisions.

Especially with the battery issue, there are so many different views, since it is difficult to do the right thing. So YES, I understand all your concerns. And with continuing doubts it is better to retire this suspicious battery...

@mnis
Touchè! Will try to observe first the flight times and temperatures, while at the same time keeping a close watch on the “bulge”. If indeed there is a significant difference from my “control battery”, then disposing of said battery would be in order.

Btw, I crashed my Mavic a month ago, around 3-meters high after one of the props detached. I had it shipped to an authorized DJI REPAIR CENTER and it’s all okay now. I asked and was told that the cause of this was the shaft got rusty. But then, this I would explain in detail on another thread that I would start soon. In the meantime, here’s a picture of that rusty shaft.

I would give a heads-up on this thread for those who may be interested.
Pic attached:

 

[Nosebump]

Lithium is the bad boy here. It's highly reactive and flammable when exposed to air, and in particular moisture. In fact, in the lab, it's stored in (-oddly) mineral oil. Swelling in a battery IS an indication that its protective membrane has been compromised. -Not an absolute, but a strong indicator, and something that I would keep an eye on.

After reviewing the pictures though, I must agree that I don't see any abnormal (-or any) swelling. I've seen batteries that have swelled, and there's usually no doubt. In cell phones, they'll actually push the LCD and digitizer loose from the cell phone body. Removing that battery becomes an urgent task.

 

[Shaughan]

@mnis
Touchè! Will try to observe first the flight times and temperatures, while at the same time keeping a close watch on the “bulge”. If indeed there is a significant difference from my “control battery”, then disposing of said battery would be in order.

Btw, I crashed my Mavic a month ago, around 3-metersView attachment 59320 high after one of the props detached. I had it shipped to an authorized DJI REPAIR CENTER and it’s all okay now. I asked and was told that the cause of this was the shaft got rusty. But then, this I would explain in detail on another thread that I would start soon. In the meantime, here’s a picture of that rusty shaft.

I would give a heads-up on this thread for those who may be interested.
Pic attached:

Hey mate is there a reason for this rust ?

 

[mnis]

I do not know if DJI has released an official statement on their own batteries ...

Anyway, the included BMS is very advanced. I think it's very reliable and safe. In no case, this is stupid model LiPo's. And the battery cells are obviously more than just standard goods.

In addition to the integrated charge controller, the voltage and temperature monitoring, there are other internal diagnostic functions that can determine a very accurate health of the battery.

Thus, in principle, battery warnings regarding the condition are issued in good time.

Those who ignore warnings and visible state characteristics are punished in most cases with a battery cut OFF. This is certainly worst case during the flight, and sometimes it also affects reasonable users.

Even if a good knowledge about meaningful battery care and safe use is present, it can sometimes be surprisingly uncomfortable.

Is there anything technical that never fails?

But I think that in relation to the sold battery units, there is only a very small amount of actually failing batteries. And it would have been at least 3 to 4 times more batteries than aircraft produced.

There are almost no reports of DJI batteries causing fires or bad scenarios. And that certainly has nothing to do with the fact that there are only highly intelligent DJI users ...

 

[mnis]

@mnis
Touchè! Will try to observe first the flight times and temperatures, while at the same time keeping a close watch on the “bulge”. If indeed there is a significant difference from my “control battery”, then disposing of said battery would be in order.

Btw, I crashed my Mavic a month ago, around 3-metersView attachment 59320 high after one of the props detached. I had it shipped to an authorized DJI REPAIR CENTER and it’s all okay now. I asked and was told that the cause of this was the shaft got rusty. But then, this I would explain in detail on another thread that I would start soon. In the meantime, here’s a picture of that rusty shaft.

I would give a heads-up on this thread for those who may be interested.
Pic attached:

I suppose you could not fix the propeller safely, or thought he was locked in place. The rust has prevented a safe attachment of the propeller. I would also be interested, is there a permanently humid environment, or were there flights in very humid climates? Maybe @Thunderdrones can give you some additional information.

 

[Balko]

I was told that the rust could have been triggered by always leaving the props attached even during storage. I guess they’re suggesting accumulation of moisture...especially after getting wet under light and sudden rain.
My query next time I get in touch with them is something I missed to ask. “Just how can a rusty shaft cause a prop to detach?”

 

[Balko]

I suppose you could not fix the propeller safely, or thought he was locked in place. The rust has prevented a safe attachment of the propeller. I would also be interested, is there a permanently humid environment, or were there flights in very humid climates? Maybe @Thunderdrones can give you some additional information.

Another “touchè” on that point. I come from the South East part of Asia and “humidity” is greatly a part of our climate here. Aside from that, condensation may have played a role at times, whenever the drone bag is suddenly brought out from a cold airconditioned room to the relatively warm humid weather outside during early mornings. Even my iPad’s display start to be foggy.

 

[Balko]

Btw @mnis, I already made a test flight of the Mavic using the “bulged” battery. I was forced to quickly land, though, because it started to drizzle.
The MP had 17min of flight with remaining battery power at 29%. The temp reached over 54C.

 

[mnis]

I think it can actually accumulate moisture in the propeller lock if the propellers are not removed after a flight in rain or fog and many days pass before the next flight.
Usually very little rust collects on a surface of metal which in fact can complicate installation of the propeller. Anyway, I assume that it is stainless steel.

Did you check it before flying, that the holding mechanism worked correctly, and the propeller is engaged?

If YES, then it seems almost impossible for me to fail the propeller lock.

Sorry, but my current guess is:
Insufficient care before the start. Maybe a flight checklist makes sense. It also helps to reconstruct actions on warranty issues.

 

[Balko]

I think it can actually accumulate moisture in the propeller lock if the propellers are not removed after a flight in rain or fog and many days pass before the next flight.
Usually very little rust collects on a surface of metal which in fact can complicate installation of the propeller. Anyway, I assume that it is stainless steel.

Did you check it before flying, that the holding mechanism worked correctly, and the propeller is engaged?

If YES, then it seems almost impossible for me to fail the propeller lock.

Sorry, but my current guess is:
Insufficient care before the start. Maybe a flight checklist makes sense. It also helps to reconstruct actions on warranty issues.

I certainly agree with your observation and recommendations. Yes, the usually forgotten “pre-flight” checklist that most of us here used to practice when we were just starting. Usually, taken for granted now, most likely because of over confidence after years of flying. Hmmmm.

 

[mnis]

You could buy an outdoor case, if not already there, and put some moisture binder in it. There are good moisture binders that change color (for example: orange to green) as soon as saturation is reached. Then you can reactivate it, for example, if it is dried in the oven. Unfortunately, I have only one German product as an exemplary example, but I'm sure you'll get it cheap in Asia. This is a great thing that can be used multiple times to protect expensive equipment from moisture. In addition, you could apply in the future on sensitive areas of the drive units a very small amount of precision mechanics oil or gun oil. That should prevent further problems.

Chemical composition:
SiO2 content: 99.7% by weight
Indicator content: 0.09% by weight

 

[mnis]

Btw @mnis, I already made a test flight of the Mavic using the “bulged” battery. I was forced to quickly land, though, because it started to drizzle.
The MP had 17min of flight with remaining battery power at 29%. The temp reached over 54C.

I would basically start landing at 30 percent anyway. And with more than 25 percent I would like to have contact with the ground again
I think 17 minutes, that's an acceptable result. Everything looks normal to me. 54 degrees Celsius are high, but (still) I see no reason for concern here. That's what I assumed (felt) in my batteries, so I think it's normal.

What was the ambient temperature?
Was it windless?
Do you know the production date of the battery?

The estimated capacity is almost 3500mAh, and cell drift is also acceptable after 60% usage.
Well, I would use this battery until only 15 minutes flying is possible. After that I would use the Battery as a backup on the way to charge my smartphone, the remote control or play around on the ground with DJI Go.

Strange:
Whenever I see scrennshots of the battery information of other users, I find that I've never even seen capacity info. Do you see this information only during the flight? Or is there a difference between the Go Apps (Android / Apple)?

 

[Balko]

I would basically start landing at 30 percent anyway. And with more than 25 percent I would like to have contact with the ground again
I think 17 minutes, that's an acceptable result. Everything looks normal to me. 54 degrees Celsius are high, but (still) I see no reason for concern here. That's what I assumed (felt) in my batteries, so I think it's normal.

What was the ambient temperature?
Was it windless?
Do you know the production date of the battery?

The estimated capacity is almost 3500mAh, and cell drift is also acceptable after 60% usage.
Well, I would use this battery until only 15 minutes flying is possible. After that I would use the Battery as a backup on the way to charge my smartphone, the remote control or play around on the ground with DJI Go.

Strange:
Whenever I see scrennshots of the battery information of other users, I find that I've never even seen capacity info. Do you see this information only during the flight? Or is there a difference between the Go Apps (Android / Apple)?

It was cloudy and quite windy when I flew it yesterday. Not sure about the production date but it was the bat that came with the MP when I bought it when it was still quite new in the market.

I use an iPad Mini4 and it does show up everytime I click on the battery icon in Go4 app.

 

[mnis]

It was cloudy and quite windy when I flew it yesterday. Not sure about the production date but it was the bat that came with the MP when I bought it when it was still quite new in the market.

I use an iPad Mini4 and it does show up everytime I click on the battery icon in Go4 app.

Then I would say 17 minutes were even a good flight time. With no wind, it might even have been 19 minutes. The Go App is a mystery to me. The production date is shown in the battery info, I mean where the charging cycles are shown. I can not explain why the capacity is not displayed. Maybe I will re-install the app or open a new topic. I suspect the production date will be February 2017, just like my batteries. This wine (this battery) has a good vintage ... LoL ...

 

[Balko]

Then I would say 17 minutes were even a good flight time. With no wind, it might even have been 19 minutes. The Go App is a mystery to me. The production date is shown in the battery info, I mean where the charging cycles are shown. I can not explain why the capacity is not displayed. Maybe I will re-install the app or open a new topic. I suspect the production date will be February 2017, just like my batteries. This wine (this battery) has a good vintage ... LoL ...

Btw, I flew the MP with the other normal battery yesterday morning. 16min flight time with around 30-ish% power left and temp of around 50C when I landed. Somewhat same performance with the other battery. Same windy condition.