An odd thing happened with the Spark last week but I can't find any indication of it in the flight log. I was hoping someone else might see what I don't.

I was bringing the Spark back at the end of a flight when it stopped six feet from me and began beeping rapidly. The battery was low so my first thought was auto RTH and hit the cancel button but the beeping didn't stop and the Spark wouldn't respond to the sticks. It just hovered in place, still beeping rapidly, not slowly like RTH. (I was on skis at the time and slid forward to grab it but muffed it which resulted in a forced landing in the snow and a bleeding thumb, but that's another story).

Besides the beeping, the lights were flashing red like crazy which indicates a critically low battery. Also, this happened within ten feet of a couple of large metal wheels (4-5 feet diameter) which might have caused a disconnect. Whatever the problem was, it doesn't seem to show up in the log but I'd kinda like to know for future reference. Is there something I'm missing or did it just not get recorded?   

https://www.phantomhelp.com/LogViewer/367Q0ZFCYH0GYPZ2KEOU/

I'd say, check older flight logs an look for the battery status.
This may have to do with it :

10m 41.5s

P-GPS

21satellites

-1.3ft

0.7ft

0mph

33.7ft

24%

10.612V

3.55V

3.546V

3.52V

0.034V

10m 41.7s

P-GPS

21satellites

-1.6ft

0.3ft

0mph

33.6ft

24%

10.438V

3.482V

3.495V

3.46V

0.034V

S-e-ven Posted at 12-26 22:10
I'd say, check older flight logs an look for the battery status.
This may have to do with it :

Yes, there were more yellow readings in one or two previous flight logs from that day but those flights were normal without any incidents. I don't know what they mean. I've only seen them in red before (in others' flight logs, not mine).

So, is the log saying that the batteries went critically low at 23 percent, before auto RTH could be initiated? That doesn't seem to make sense. (The temperature was around -5 C with a stiff breeze so maybe that contributed to it?)

Prairie Chicken Posted at 12-26 23:18
Yes, there were more yellow readings in one or two previous flight logs from that day but those flights were normal without any incidents. I don't know what they mean. I've only seen them in red before (in others' flight logs, not mine).

So, is the log saying that the batteries went critically low at 23 percent, before auto RTH could be initiated? That doesn't seem to make sense. (The temperature was around -5 C with a stiff breeze so maybe that contributed to it?)

10 minutes into the flight, the batts should still be on temperatur, methinks.
I have not seen this on all 3 cells  in the same time.
bu b/c of still 24% left,  before/after, I'd say it is a wrong reading/writing in the record.
But just DJI knows, what caused it, why it is shown like this.
What can be the reason.

One of my birds had it on "bump start" issues, just one cell went "deep".
for some time always only with one battery.
But in the end it happens  with all batts and they fly (still) one on another bird and with the "bumpy one" after repair! (Don't know what DJI did, the record did not make it with the bird to me)

My guess: It is the power management, that is "doing something wrong".
Keep an eye on it, let DJI analyze and wait for there ideas!

S-e-ven Posted at 12-27 05:57
10 minutes into the flight, the batts should still be on temperatur, methinks.
I have not seen this on all 3 cells  in the same time.
bu b/c of still 24% left,  before/after, I'd say it is a wrong reading/writing in the record.

Two of the batteries are a couple of years old so maybe the yellow values mean they're in their Golden Years now. Thanks for your help, S-e-ven, I'll see if I can get to the bottom of this.

I feel kind of lucky that it happened where and when it did. If the AC was going to auto land, I'm at least thankful it wasn't over the middle of the lake in summer.

How many cycles does the batteries have?

And auto landing is a thing that is happening, in case I learned that right,  after little time (20 secs or such?) when there is no RC connection PLUS no GPS (no RTH possible)  for the spark
Descending  down to hover 3ft over ground, I think
Till battery ends, a little drift gets it in a leaf or such, or someone grabbed it!

So one solution for "fly aways", no GPS, but still RC connection and seeing the bird,  could be: RC off before bird flown out of sight!

Its the obstacle avoidance

Spark_Pilot_XxXx Posted at 12-27 14:25
Its the obstacle avoidance

I laughed at that at first. I've never used OA. It has been off by default since I bought this drone, but I believe you're right. Somehow, it's on now. It doesn't explain the flashing red lights but everything else makes sense. Thanks. (sheepishly)

S-e-ven Posted at 12-27 08:35
How many cycles does the batteries have?

I haven't checked yet but it looks like the mystery is solved. But I'll check them for sure.

I found out at PhantomHelp that the low battery cell values in the flight log are coloured yellow by the flight log reader, not by DJI. It isn't an official warning or anything, it just draws attention to lower than normal values.