Battery went from 100% to critically low after few seconds of flying.

[pchajj]

Hello everyone!
I am new to this forum although having owned my mavic for a couple of years now. The last flight I did was just about to end with a crash. After a couple of minutes I took off with my fully charged *new* battery (yes, I am sure it was fully charged), a "critically low voltage error" appeared on my screen and drove my mavic into a forced landing. I was lucky to have saved it just in time. when I got the quad back, I checked on the Go4 app and it says that all cells are at around 4.10V (which is logical as I flew for a really short time). I then pressed the battery's button to see the voltage level and only the first led was blinking, which was contradicting what was mentioned in the app. I did not attempt to charged as I was afraid that the voltage sensor of the battery itself was damage and did not want to overcharge the battery and cause another problem. This is the first time that such a thing happened to me, and would be very grateful for any help from you guys!

Thanks a lot!

ps: I will try to see if any additional info appears on the assistant app as soon as I go back home to my laptop.

 

[Repaid1]

How old was this "new" battery? When is the last time you flew it without issue? Correct storage procedure and monthly maintenance? Do you have other batteries and are they exhibiting this same issue? I would say put that battery back in and arm motors and bring it up to about 2-3 foot and let it drain normally to auto land. Allow it to cool and settle for about a hour and then let it fully charge again.

Check battery function from button for full charge indication, then power up and check app side. Hover test again and see what happens. IF this repeats then you have a defective battery and as it is "new" get a replacement.

 

[Deleted member 103366]

With Phantom 3's I have noticed that there seems to be a relationship between how recently the battery was charged and how quickly the charge is drained. The impression I get is that an old charge drains much more quickly than a new charge.
Whether this is correct I do not know, but it might be worth checking if something similar happens with your MA1 batteries.
If correct I am left wondering why this should be. (I have a fair few P3 batteries and it easy enough to get their history muddled up in my mind plus I haven't flown any in a couple of months.)

The above said, the general advice that I have seen is, charge the battery shortly before flight e.g. the day before the flight or earlier on the day of the flight. I have also seen mention that you should not use a battery IMMEDIATELY after it has been charged.

With regards to Repaid1's " how old is the battery?" The production date may be visible in the app and or in the .txt flightlog, column DQ or 121 entitled "CENTER_BATTERY.productDate" in the csv output from CsvView.

 

[Repaid1]

With Phantom 3's I have noticed that there seems to be a relationship between how recently the battery was charged and how quickly the charge is drained. The impression I get is that an old charge drains much more quickly than a new charge.

My Phantom 3 batteries exhibit a somewhat notable characteristic. You could charge them the night before or earlier in the day. But while battery status on App would show them not at 100% at flight time. I believe it had to due with how the BLM cut off at "Full" charge.

It was then as now that DJI recommends no more than 24 hours in between charge and flight. Back then we called it "Topping off or Push Charge". About 1/2 hour before heading out "we" would put them back on charger and if they didn't charge we would then turn them on manually and charge would resume. That developed procedure was pretty much adopted back then to have your batteries at a true 100%. The P4 batteries would allow that procedure for a bit, but I believe further battery updates on that model in battery management made it not needed.

Subsequent models changed battery management further till now doing the above procedure yields no results. But to the OP and this reported issue this isn't in line with the P3 batteries. IF his battery display showed full voltage (4 lights) and his App reported 98%-100% on lift off something is outta whack. That is why I needed further info and wanted him to do a maintenance cycle as like the P3 batteries his batteries may need a Calibration cycle. But I didn't elaborate as yet to do that as "We" don't have the info available with his posed question and supplied info.

I just wanted to know that he didn't leave these batteries unattended for months/year and then charged them like so many reports...which everyone should know means the battery is junk due to improper maintenance. I think OP threw me off with the "new" typing...Does that mean new from store, new to him (used) or just fully charged?

 

[boblui]

If you can upload the flight log to DJI Flight Log Viewer | Phantom Help perhaps more insight can be obtained. The instruction is given at the bottom of that webpage

 

[PHZ]

I would upload your data to an app titled Airdata. It will give you a ton of information about your battery and each cell in it.
My guess is that you lost a cell in the battery. Airdata will tell you if that is the case.

 

[hiflyer201]

unequal cell.. Airdata will show that type of information. Don't use the battery it will happen again..maybe not the next flight but soon. voice of experience

 

[dave canada]

I just put 3 down some go slow and the others will quit with out warning I,m keeping better track of them on airdata now seems i always have to learn these things the hard way ,cheaper too toss them then to repair the aircraft,

 

[pchajj]

How old was this "new" battery? When is the last time you flew it without issue? Correct storage procedure and monthly maintenance? Do you have other batteries and are they exhibiting this same issue? I would say put that battery back in and arm motors and bring it up to about 2-3 foot and let it drain normally to auto land. Allow it to cool and settle for about a hour and then let it fully charge again.

Check battery function from button for full charge indication, then power up and check app side. Hover test again and see what happens. IF this repeats then you have a defective battery and as it is "new" get a replacement.

It has only 38 charges.
Yes all batteries are adequately stored!
Will try the hovering thing today thank you!
As for the replacement it doesn't really work in my country, we don't have official dji stores (like apple stores) instead we just have certified retailers that are not really happy to replace any damaged part

 

[pchajj]

If you can upload the flight log to DJI Flight Log Viewer | Phantom Help perhaps more insight can be obtained. The instruction is given at the bottom of that webpage

will do that thanks!

 

[pchajj]

Hello everyone!
I am new to this forum although having owned my mavic for a couple of years now. The last flight I did was just about to end with a crash. After a couple of minutes I took off with my fully charged *new* battery (yes, I am sure it was fully charged), a "critically low voltage error" appeared on my screen and drove my mavic into a forced landing. I was lucky to have saved it just in time. when I got the quad back, I checked on the Go4 app and it says that all cells are at around 4.10V (which is logical as I flew for a really short time). I then pressed the battery's button to see the voltage level and only the first led was blinking, which was contradicting what was mentioned in the app. I did not attempt to charged as I was afraid that the voltage sensor of the battery itself was damage and did not want to overcharge the battery and cause another problem. This is the first time that such a thing happened to me, and would be very grateful for any help from you guys!

Thanks a lot!

ps: I will try to see if any additional info appears on the assistant app as soon as I go back home to my laptop.

Here is the link of the flight log.

After going through it, i noticed that the battery had a mind of its own, while the battery % seemed to be almost constant around 97% until 1,12s, where it jumped from 95% to 0%.

 

[Meta4]

Here is the link of the flight log.

After going through it, i noticed that the battery had a mind of its own, while the battery % seemed to be almost constant around 97% until 1,12s, where it jumped from 95% to 0%.

The warning at the start of the flight is probably quite significant.
It said:
Battery Temperature Below 15°C (59F). Warm battery to above 25°C (77F) before flying.
At very low temperatures, the battery cannot supply voltage as it can in more normal temperatures.

The % indication is meaningless with a faulty battery or one that has partially discharged.
The cell voltage is what matters and yours was already below critical low voltage level (3.3V) 44 seconds into the flight, under the stress of climbing in sport mode.

You can configure the DJI Go 4 app to display the average cell voltage as well as a % indication.
See the top right here:

 

[boblui]

.... i noticed that the battery had a mind of its own, while the battery % seemed to be almost constant around 97% until 1,12s, where it jumped from 95% to 0%.

Your incident is exactly the same as this recent case in which the battery % dropped from 88% to 0% mid flight ( Mavic went from 96% battery at takeoff to 0% ). At the beginning, the battery % figure was computed from the amount of mAh discharged instead of the voltage because the voltage fluctuates with the loading hence not a good way to measure the amount of battery energy left. However, when the cell voltage dropped to an abnormally low level ( 2.8 ~ 2.9 V ), the BMS ( Battery Management System, the small computer inside the battery ) realized that the battery had completely discharged way earlier than expected so it changed the battery % figure to zero.

Fortunately, the cell voltage did not continue to drop but rised back to about 3.2V as the loading was reduced during landing. It seems that this is the common characteristics of the battery of Air 1 when it goes bad.



The battery capacity memorized by the BMS was adjusted from 1994 mAh to 40 mAh ( red line in the chart ) during the flight. It will be extremely interesting if you can charge the battery to full again and do hovering at low height and see how the battery % figure will change. My guess is that it will go from 100% to 0% quickly but in a more gradual manner.

 

[pchajj]

The warning at the start of the flight is probably quite significant.
It said:
Battery Temperature Below 15°C (59F). Warm battery to above 25°C (77F) before flying.
At very low temperatures, the battery cannot supply voltage as it can in more normal temperatures.

The % indication is meaningless with a faulty battery or one that has partially discharged.
The cell voltage is what matters and yours was already below critical low voltage level (3.3V) 44 seconds into the flight, under the stress of climbing in sport mode.

You can configure the DJI Go 4 app to display the average cell voltage as well as a % indication.
See the top right here:

okay that seems logical, it was actually cooler than usual on this day

 

[Meta4]

okay that seems logical, it was actually cooler than usual on this day

The battery stayed below 15° C until 0:45.7
It wasn't until 1:32.7 that it reached 25° C

 

[Heavydpj]

Correct storage procedure and monthly maintenance?

What is a valid "monthly maintenance?"

 

[dave canada]

my pro did the same to me with the aircrasft at 134 ft up and it went to zero and droped like a rock i missed the catch , hopefully u didn,t have to go thur the repairs on the aircraft also