Last Saturday the fully charged battery in my MA dropped instantly from 90% to zero

[Biggles54]

Last Saturday the fully charged battery in my MA dropped instantly from 90% to zero and I didn't have enough time to prevent my lovely drone from ditching in the river on its way back to me. The batteries and MA are 18 months old, I am currently pursuing DJI with a claim. Luckily I have all the data on my phone.

 

[BigAl07]

Welcome to the forum

 

[Thomas B]

Welcome to the forum.

Actually just had a battery on my M2P do this... was 99% at takeoff (charged the night before) and about 45 seconds later I got a low battery warning showing about 20% battery. I flew a battery before and one after so I do think it’s something in the battery. No bulging, also turned the drone off and on which confirmed the reading. That battery charged fine. Due to heat and work schedule it will be a couple of days before I can test the battery in question.

 

[Biggles54]

thanks for the welcome guys.
I'm trying to pursue some sort of compensation via the retailer and DJI but not looking promising.
I've attached my flight data, is anyone able to please pull from this the performance of the battery?!
Or is this the wrong file?

 

[Biggles54]

Good news (for me!). After a few emails and pleading with to DJI, and with the help of the Melbourne D1 Store, they asked for all my flight records and data files.
DJI then agreed it was a warranty case and that they would replace my 18 month old MA. Big yay!
I received the brand new MA yesterday along with a new battery.

In the meanwhile I have bought a new Pro 2 along with the Smart controller, have almost flattened the batteries just playing with the settings and getting to know the bigger beast.
Squeezed in 5 minutes in the air late yesterday - very impressed with the camera and the mobility of such a heavier drone. I have a possible buyer for my new MA and gear so this will help bring my costs down.

 

[sar104]

Good news (for me!). After a few emails and pleading with to DJI, and with the help of the Melbourne D1 Store, they asked for all my flight records and data files.
DJI then agreed it was a warranty case and that they would replace my 18 month old MA. Big yay!
I received the brand new MA yesterday along with a new battery.

In the meanwhile I have bought a new Pro 2 along with the Smart controller, have almost flattened the batteries just playing with the settings and getting to know the bigger beast.
Squeezed in 5 minutes in the air late yesterday - very impressed with the camera and the mobility of such a heavier drone. I have a possible buyer for my new MA and gear so this will help bring my costs down.

That's a good result, but I'm not sure that I agree with their diagnosis. The cause of the battery percentage reading going to zero was the additional current draw when you applied full up throttle and full forward elevator, which did cause cell voltage collapse:



Looks like a bad battery, but I don't see anything wrong with the aircraft.

 

[Biggles54]

The main problem was that the aircraft dropped into a river, there was not enough time to get it back to the shore.
Bad battery = lost drone.
I've attached the flight record if that helps.

 

[sar104]

The main problem was that the aircraft dropped into a river, there was not enough time to get it back to the shore.
Bad battery = lost drone.
I've attached the flight record if that helps.

The graphs above are from your log - you posted it in post #4. I'd have looked earlier but I must have missed this thread. I also completely missed that you mentioned that it ditched in the river, in which case replacing both is clearly necessary.

One question though - the cell voltages dropped quite precipitously at the start of the flight, which suggests that the battery might possibly have been in an auto-discharge state. Had you charged the battery recently or had it been sitting around fully charged? It's also indicating a manufacture date of January 2018 and only one charge cycle - is that correct?

 

[Biggles54]

I'm not an expert of the batteries, still learning.
I had traveled quite a distance the day before to the town where I flew the drone.
This particular battery (my no. 2 of 3) hadn't been used much over the 18 months and prior to the flight was connected to my car charger.
But it did have more than one charge cycle, I would have charged it more than say 10 times.

 

[sar104]

I'm not an expert of the batteries, still learning.
I had traveled quite a distance the day before to the town where I flew the drone.
This particular battery (my no. 2 of 3) hadn't been used much over the 18 months and prior to the flight was connected to my car charger.
But it did have more than one charge cycle, I would have charged it more than say 10 times.

OK - sounds like it had gone bad. I'm impressed that they warrantied an 18 month old battery and aircraft.

 

[Biggles54]

My warranty and Care Refresh ran out in Feb 2019, so I was lucky.
I know my retailer was helping me in the background.