Battery error - 56% to 0% in a .1 of a second

[DexRexMex]

Is this a hardware issue seeing as the voltage is still there? Should I not use the battery again?​

DJI Flight Log Viewer - PhantomHelp.com

Thanks for your help in advance​

 

[Sam36401]

It looks like the battery had been sitting around unused for a while and had been self-discharging.
I would charge it to 100% then use it and check the log file again.

 

[maggior]

From the log, it landed on top of a building. The low voltage errors occurred midway through the flight. Why didn't you immediately try to bring it back at that point? It could have just dropped out of the air and injured somebody.

 

[slup]

....Should I not use the battery again?​

It looks like the battery had been sitting around unused for a while and had been self-discharging.
I would charge it to 100% then use it and check the log file again.

That battery was beyond rescue both before & after this flight... don't use it again, instead dispose of it in a proper way.

This battery didn't only get a failure in one of the cells, which is typical if the battery have been sitting for a long time & self discharged & got the cell voltages go out of balance.

This battery showed major voltage drops every time you demanded amp draw from it... the reason for this is most likely a very high internal resistance. A charge will not fix this... it will happen again & then you maybe lose your drone also. On top of this, this flight pushed all cells well below 3,0V, which created even more permanent damage.

The chart below depict the entire flight & show graphs for the battery percentage (calculated by the BMS chip), the cell voltages, the flight pattern regarding height & heading speed (these require a lot of amp draw).

As seen below, the cells show very little voltage deviations... instead they show major voltage drops every time the battery needs to deliver amps... every time you ascend or accelerates horizontally. When you let off the sticks the voltage recovers somewhat but never to the same level as just before the amp draw.

46sec after take off & after 4 ascends & 3 accelerations all cells was well below 3,0V & the forced "critical low battery voltage" landing started (pink background color).

The reason for that the battery percentage suddenly dropped to 0% was that the BMS chip gave up... it couldn't make sense of the rapid voltage decrease & figured out that those 60% at start in fact was wrong... this behavior is typical when batteries fail.

(Click on the chart to make it larger, check the legend under the chart for what the graphs represent)
(Have placed the chart marker where the voltage is as lowest at 46sec... the graph values from there can be read off in the legend)

 

[DexRexMex]

That battery was beyond rescue both before & after this flight... don't use it again, instead dispose of it in a proper way.

This battery didn't only get a failure in one of the cells, which is typical if the battery have been sitting for a long time & self discharged & got the cell voltages go out of balance.

This battery showed major voltage drops every time you demanded amp draw from it... the reason for this is most likely a very high internal resistance. A charge will not fix this... it will happen again & then you maybe lose your drone also. On top of this, this flight pushed all cells well below 3,0V, which created even more permanent damage.

The chart below depict the entire flight & show graphs for the battery percentage (calculated by the BMS chip), the cell voltages, the flight pattern regarding height & heading speed (these require a lot of amp draw).

As seen below, the cells show very little voltage deviations... instead they show major voltage drops every time the battery needs to deliver amps... every time you ascend or accelerates horizontally. When you let off the sticks the voltage recovers somewhat but never to the same level as just before the amp draw.

46sec after take off & after 4 ascends & 3 accelerations all cells was well below 3,0V & the forced "critical low battery voltage" landing started (pink background color).

The reason for that the battery percentage suddenly dropped to 0% was that the BMS chip gave up... it couldn't make sense of the rapid voltage decrease & figured out that those 60% at start in fact was wrong... this behavior is typical when batteries fail.

(Click on the chart to make it larger, check the legend under the chart for what the graphs represent)
(Have placed the chart marker where the voltage is as lowest at 46sec... the graph values from there can be read off in the legend)
View attachment 169334

Thank you so much for this information. I will dispose of the battery properly.

 

[Sam36401]

Great analysis, @slup
@DexRexMex ... take his advice. not mine.

 

[DexRexMex]

From the log, it landed on top of a building. The low voltage errors occurred midway through the flight. Why didn't you immediately try to bring it back at that point? It could have just dropped out of the air and injured somebody.

I would have liked to, for sure. The safest and quickest route, in the 30 seconds it took to land, was the direction I was facing (and knowing I had access to the roof of that building) keeping the drone away from people.

 

[maggior]

I would have liked to, for sure. The safest and quickest route, in the 30 seconds it took to land, was the direction I was facing (and knowing I had access to the roof of that building) keeping the drone away from people.

That makes sense.. Must have been a heart thumpin' 30 seconds...yikes!

 

[Conservative Nihilist]

Reminds me of my late Phantom 3S' triumphal return from a fully autonomous 6-mile round-trip Litchi waypoint sortie. At the very instant when I selected manual flight to lower the drone down for a feather-light touchdown, the battery died at an altitude of 140 feet, whereupon gravity, my dastardly and cunning nemesis, asserted itself with a vengeance. The rest is somber history.