Mavic 2Pro - Battery not recognized

[BigBoozer]

Hi folks, I flew yesterday a perfect Waypoints flight with my Mavic 2 Pro. Landed ok, battery still at 30% capacity. Changed my takeoff point by 500 m or so. Started again with the remaining battery, it flew all OK until the Low Battery signal alerted me. I ordered RTH, the bird came back regularly, not a problem. Changed the drained battery with a fresh one, 100% charged.
The Smart Controller signalled 'Cannot Take Off' and Battery 0%. The menu does not recognize the battery, no serial number, no working hours, nothing.
Changed battery with a third one, also 100% charged. Same story. Went home, tried to understand, recharged the first drained battery (which worked OK) and tried it again on the bird: same message.
RC says 'Battery Signal Error. Please check the battery connection.' The fact is that I can see on the RC the video images from the drone, it is responding to gimbal adjustments, it is regularly recording videos and photos from the grounded drone. There is plenty of battery, for sure! But it won't start motors and take off, because it says Battery 0%. Could it be a problem in the bird's built-in connection plug? Sort of shortcircuit? Three new batteries don't die in a minute. The bird is in perfect conditions, has only 66 flights, 12 hours in the air, 129 Km flown. The three batteries must have 20-25 flights each.

Any suggestion or similar experience?

By the way, I'm trying to reset drone and RC back to factory settings, just to try another solution, but I do not understand how to do it using DJI Assistant 2 for Mavic 2.
It's really a poor program.

Thanks.

 

[FLDave]

Why are you trying to reset the drone to factory settings? Do you really think the problem is with the drone? Since you are not familiar with DJI Assistant isn't there a probability that you would make the problem worse?
I assume the 3 batteries are all DJI originals with the Mavic 2 Pro?
Is there any visible damage to the battery contacts in the drone? Battery contacts in the drone can get damaged.

 

[BigBoozer]

Why are you trying to reset the drone to factory settings? Do you really think the problem is with the drone? Since you are not familiar with DJI Assistant isn't there a probability that you would make the problem worse?

Because it might help resetting the drone. Yes, I am aware that things could go wrong.

I assume the 3 batteries are all DJI originals with the Mavic 2 Pro?

Yes

Is there any visible damage to the battery contacts in the drone? Battery contacts in the drone can get damaged.

No, the male plug of the drone is integer.

 

[Yorkshire_Pud]

I would check the male and female contacts of the drone and battery and see if any thing is bent or debris has masked a contact.

 

[BigBoozer]

I would check the male and female contacts of the drone and battery and see if any thing is bent or debris has masked a contact.

Thanks, I'm out of home now, when I'm be back I'll check the contacts of the batteries. I'm positive that on the drone they were and are OK.

 

[FLDave]

As you described the issues/observation it seems to me to be a sudden failure of something directly related to battery power. To may thinking software/firmware on the drone wouldn't suddenly fail. Sudden failures to my thinking would more likely be mechanical/electrical. This goes back to the battery contacts.
On the other hand the drone is getting correct electrical supply to start up with no errors, so perhaps this would lead to battery contacts OK.
The controller gets its information via radio waves from the drone. So, there may be a problem with controller app or the drone sending bad battery information. Does your controller show all other relevant information about the drone when powered on stationary? GPS and other flight settings?
Can you provide a close-up image of the battery contacts in the drone?

 

[old man mavic]

@BigBoozer another thing to check,would be to make sure that there is no slight swelling on the underside of the batteries which is preventing the contacts to complete the circuit
and also if there have been any recent firmware updates if the battery was part of that update then each battery needs to be updated as well

 

[BigBoozer]

As you described the issues/observation it seems to me to be a sudden failure of something directly related to battery power. To may thinking software/firmware on the drone wouldn't suddenly fail. Sudden failures to my thinking would more likely be mechanical/electrical. This goes back to the battery contacts.
On the other hand the drone is getting correct electrical supply to start up with no errors, so perhaps this would lead to battery contacts OK.
The controller gets its information via radio waves from the drone. So, there may be a problem with controller app or the drone sending bad battery information. Does your controller show all other relevant information about the drone when powered on stationary? GPS and other flight settings?
Can you provide a close-up image of the battery contacts in the drone?

Thanks. The controller showed everything normally, I could tweak all the settings as usual. Only the Battery section of the menu does not identify any battery.
I'm out of home now, when I'm be back I'll check the contacts of the batteries. I'm positive that on the drone they were and are OK.

 

[BigBoozer]

@BigBoozer another thing to check,would be to make sure that there is no slight swelling on the underside of the batteries which is preventing the contacts to complete the circuit
and also if there have been any recent firmware updates if the battery was part of that update then each battery needs to be updated as well

Thanks, I'm positive there is no swelling, they're quite new and well behaved. I have another two Mavic Pro 1 drones, both have had swelling batteries, I'm well aware of that problem. Another problem is... there are few spare batteries for MP2 and they cost ... a kidney!

 

[FLDave]

I found some battery pinout information here: Here are the pinouts of the Mavic Pro battery
You might look for more information on this forum.

 

[BigBoozer]

I would check the male and female contacts of the drone and battery and see if any thing is bent or debris has masked a contact.

And, back home, I found something I did not pay attention to before:


The four central contacts (the + line for the four elements) lost their plastic dividers... The copper contacts apparently are not bent, but who knows what happened when I inserted this battery in the drone, yesterday... This surely was the second battery I used, immediately after having exhausted the first one. God only knows how this happened, but it did.
Sh.. happens.
Therefore I can expect a nice short circuit of the drone board in the power inlet area...

THANKS TO ALL FORUM MEMBERS who helped!

 

[Yorkshire_Pud]

The attached is the pinout printed on the back of DJI M2P/Z car charger.
There is a recent thread here or on the DJI forum where there is damage to the battery terminals dividers of, I think, an M2P/Z. I can't remember if the damage was on the battery or the drone but there were suggestions for a means of repair. Try googling for it.

 

[FLDave]

Interesting. So logical analysis leading to battery contacts was correct.
Surprising, however, is the suspicion of circuit board problems, but your suspicion is likely correct.
Do you now send to DJI for repair, attempt yourself, or do some electrical inspection first.
By the way, for my Air 2s I have battery and drone contact covers so contacts are never left exposed for damage when stored in bags or boxes; I found them on Amazon.

 

[BigBoozer]

Interesting. So logical analysis leading to battery contacts was correct.
Surprising, however, is the suspicion of circuit board problems, but your suspicion is likely correct.
Do you now send to DJI for repair, attempt yourself, or do some electrical inspection first.
By the way, for my Air 2s I have battery and drone contact covers so contacts are never left exposed for damage when stored in bags or boxes; I found them on Amazon.

Absolutely correct, it was. If those unprotected wires have shorted the drone's connector, I expect there would be a breaker (a fuse) to protect the rest of the circuit. I'll have it checked here in Italy tomorrow morning to attempt a first aid diagnosis. Then I'll see if to involve DJI TechServ in Holland. The battery itself is already a nice damage, at 270+ Euro !

 

[BigBoozer]

I'm glad to say that I can close successfully this thread: I went this morning to my drone shop, 50 km from my home (in Novara, for the Italian drone users looking for a reliable repair shop!) : they agreed on the diagnosis of a short circuit caused by the faulty battery contacts, they had one (one!) available power connection card, they replaced it in less than two hours and I got my repaired drone back in the early afternoon. Total: 120 Euro (less than 130 US$). I'm back in business for my summer holidays starting in a week from today.
If I had to send it to European DJI TechService (I discovered today that moved from Holland to Hungary) I would have been lucky having it back in 2-3 weeks, for (probably) a 200-250 Euro bill or worse.
Great job, Biz Model Distribution Srl Home Page ! Thanks SO much!

 

[FLDave]

Thanks for the good update.

 

[old man mavic]

@BigBoozer ,really pleased to hear you resolved your battery issue and are back in the air thanks for updating us on your progress ,i have now closed the thread