Battery dropped from 53% to 0% ,almost lost my MA

[BudWalker]

Try this one

 

[sar104]

Try this one

Standby.

 

[FMR]

Maybe try warming up the batteries before flight and then do a hover test to see how much flight time you get before critical low battery. If you start at appx. 100% and land at appx. 15%, you should get approximately 15-18 minutes of actual in-flight time. The aircraft should be able to handle sport mode in good conditions, but if your batteries are cold, that could cause problems.

Experienced similar battery cold warning yesterday on a winters day here in NZ.
Being new to the Drone scene how do I warm up the battery preflight ?

 

[Travisimo]

Experienced similar battery cold warning yesterday on a winters day here in NZ.
Being new to the Drone scene how do I warm up the battery preflight ?

They actually sell warming boxes, but many people use hand warmers or the like. Your car heater, putting them in your pocket with a hand warmer, etc. Also make sure you let the drone warm up a bit upon takeoff before flying away.

 

[BudWalker]

the cell voltage for cell1 looks normal
the cell voltage for cell2 and 3 have an issue.

cell 2 drops about the same as cell 3 increases.
It could be a balancing issue. Some "stuck" or wrongly controlled bypass (FETs).

The reason your plot looks different from @sar104 's plot is that you're using CsvView version 3.2.0 which has an older TXTlogToCSVtool. That older TXTlogToCSVtool version handles MavicPro .txt files correctly whereas the newest version of TXTlogToCSVtool does not.

 

[sar104]

The reason your plot looks different from @sar104 's plot is that you're using CsvView version 3.2.0 which has an older TXTlogToCSVtool. That older TXTlogToCSVtool version handles MavicPro .txt files correctly whereas the newest version of TXTlogToCSVtool does not.

Yes - that makes it look more like the cell excursions from previous battery events of this type. Still can't be real, so presumably either a measurement problem or a firmware issue.

If we average the values of cells 2 and 3 the result (black line) is almost reasonable, but still shows unrealistic variations.

 

[BudWalker]

For those who don't follow

[TOOL][WIN] Offline TXT FlightRecord to CSV Converter

There is a new version of TXTlogToCSVtool that appears to work for both MavicPro and MavicAir. I've attached a copy here.

This newest version of TXTlogToCSVtool will be in the next CsvView version. Existing CsvView versions can be updated to use the newest TXTlogToCSVtool by
1) download and unzip the attached .zip.
2) copy the TXTlogToCSVtool.exe in that .zip to the directory <CsvView Install Directory>/executables. Typically, this will be the
C:/Program Files(x86)/CsvView/executables directory

 

[RG1825]

I’ve since drained to below 8% on all 3 batteries as instructed by Dji and have had no issues. Maybe give it a try.

Any more issues since then? I had exactly the same issue as you with two different batteries. tried the 8% drain solution, but it is still happening! Maybe every 1 in 5 flights, always at 55% it drops immediately to 0%. All occurrences have been on days with wind warning. Not sure if that makes a difference.

 

[Jameslavis]

I had an experience on the weekend and I factored it to wind. Flying it started decreasing in 15 sec intervals. Then I let off and it went back to normal.

 

[mavicn00b]

I have a slightly different issue with one of my batteries. If i fly it out, at around 70-80% it wants to return home prematurely. Flying the same route on another battery it returns home much later are further out.

It flies the same as any of the others, stays as long in the air, so no issues there. Cell voltages look normal, most deviation is ~0.04v which is fine. It just wants to RTH way to early. Has anyone ever seen this issue before?

 

[msinger]

I have a slightly different issue with one of my batteries. If i fly it out, at around 70-80% it wants to return home prematurely.

Got a flight log we can review?

 

[buddukes]

I had a similar issue yesterday, but happened after battery hit 20%. Started returning home like normal and then jumped from 18% to 0% instantly at about 80ft and started landing. I managed to get the drone over grass and it accelerated its descent...not quite a free fall, but close enough to be scary. This happened a few weeks ago and I wrote it off as being a fluke (but the drone was close to the ground). This caused me to start looking to see if others have had a similar issue and came across this thread. I’ve now marked that particular battery. Not sure if it’s the same one from the first occurrence. Any success in diagnosing or resolving this issue? Thanks!

 

[hquant]

In my case, the battery was defective. It did not charge again after the episode. But it does not seem to be a frequent occurance, more of an outlier. But scary as hell nonetheless...

 

[mavicn00b]

Got a flight log we can review?

No I dont have it anymore. In further development, the battery (not flying at the time) was in the quad reading about 52%. When I powered down and back on it read 0% and DJI Go4 showed the same (yet cell voltages were around 3.84v mark). Lights on the battery also showed 1 bar so the battery itself thought it was depleted. Very similar to what was experienced here except I wasnt in flight fortunately.

I recharged the battery and it charged as pernormal to 100%, was able to fly without incident. The issue of the battery wanting to return home prematurely resurfaced a few cycles later. Again discharge and recharged it and that problem went away. So far so good, but there's definitey a strange trend on these batteries as per the postings on the forum. The battery itself is marked (#4) so I know which one it is and keep an eye it while using incase it wants to act up.

 

[ryan5280pro]

Thanks for the input, I didn’t think of the sport mode. Will look at that when I test it out tomorrow

Just a tip :Switch your function button on your controller to see what your battery is doing while in flight ...it’s part of your customized buttons for the controller

 

[ryan5280pro]

Just a tip :Switch your function button on your controller to see what your battery is doing while in flight ...it’s part of your customized buttons for the controller

You can also download a screen recorder app to view watch your settings or tips are telling you while in flight

 

[RG1825]

I’ve replaced my battery and haven’t had the issue since in about 20 flights.

 

[Catchyphrase]

I just had the exact same thing happen to me. Battery went from 7:31 mins to 0.

Luckily it let me control left n right to land on ground instead of forced landing into the ocean. Wouldn’t let me cancel the landing.

I sent flight log to Dji support.

 

[DanMan32]

I just had the exact same thing happen to me. Battery went from 7:31 mins to 0.

Luckily it let me control left n right to land on ground instead of forced landing into the ocean. Wouldn’t let me cancel the landing.

I sent flight log to Dji support.

You can also go up during forced landings, biasing the default descent rate.

 

[InvisibleName]

You can also go up during forced landings, biasing the default descent rate.

You have to keep the ascend stick pushed continuously to prevent it from doing a ‘forced’ landing, works until the battery runs out