Battery critically low warning ?

[KthP3]

I was out flying my p3p today and I got a battery warning critically low Landing aircraft at 35%. I used to never get a battery warning till about 20 and even then it would just start returning home. This started dropping my altitude to land the aircraft right away luckily I got it back to me in time anybody have any ideas what the problem was?

Sent from my SM-N920V using PhantomPilots mobile app

 

[msinger]

Please upload your TXT flight log here and post a link back here.

 

[KthP3]

How do I do that? Could you explain the steps please not familiar. I started out at 40% on the battery not sure if it's due to flying the Drone a few times briefly on the same battery or what. Kind of scary because it wouldn't even let me override it in DJI app

Sent from my SM-N920V using PhantomPilots mobile app

 

[msinger]

My link above contains instructions to retrieve the log from your mobile device.

 

[KthP3]

okay I will look into it is it. It's literally only about two minutes long

Sent from my SM-N920V using PhantomPilots mobile app

 

[msinger]

Starting out with the battery that low is not a good idea. If you were accelerating/ascending hard at that time, it would have made the battery level spike down pretty low. That could trigger an auto landing. It's best to start flights with a fully charged battery.

 

[KthP3]

Ok. Yea I started at 40 it went to 32 by the time I landed i was up for maybe 2 min. I kept getting a msg about out adjusting propulsion output due to battery level or something like that

Sent from my SM-N920V using PhantomPilots mobile app

 

[flyNfrank]

If you can't upload the .TXT file from that flight, or follow msinger's instructions, then you will get nothing but speculation for help.

Are you able to follow these instructions?

The file you need is in the device you have the GO app loaded on. You must connect that device to your computer and search for a folder named DJI.
Open the DJI folder and locate folder dji.pilot.
Open the dji.pilot folder and locate folder FlightRecord.
Open folder Flight Record and scroll near the bottom of the page and look for the txt file matching the flight in question. That file will look similar to this:
"DJIFlightRecord_2016-08-23_[19-22-40].txt"

At this point save a copy of that file to a folder on your desktop or any area easy for you to locate later on.

 

[KthP3]

Yes I'm aware I do not have a computer to connect to all I use is a tablet and my phone I'm going to attempt to do this on my work computer tonight

Sent from my SM-N920V using PhantomPilots mobile app

 

[Digdat0]

its very likely that the aicraft just didn't have enough power, despite the battery % showing good, to be able to keep it going. this can happen sometimes when you start under 100%, flying in wind, colder temps, etc. With the log these guys can tell ya exactly what it was, but probably because volts were low in that condition and it was fighing to keep enough voltage to keep going. This can happen despite the battery % showing a good % sometimes, especially in the conditions i mentioned. if you can get into file explorer on your phone, navigate to the ‘<devicename>\<storagedrive>\DJI\dji.pilot\FlightRecord folder and get the last flight log, or whichever that is and then post it here.

 

[flyNfrank]

I know exactly what happened, as do others here. Rather then just saying what took place he was going to be shown by the flight logs. However, he seems to not appreciate some taking the time to help.

Generally when the help is being offered, you stop everything and help the helpers get what they need. Otherwise, scratch off some coin and pay someone that doesn't mind being paid to take their time.

Anyway, it's obvious KthP3 has not read the manual, or searched topics in this forum. If he did either of the two he would know that per the Smart Batteries the #1 most important thing you do in pre-flight inspection is make sure the battery has been charged 100% before the Aircraft is powered on. Even if you are just going to start the Aircraft and shut it off a couple of minutes later. Get yourself in the habit of NOT taking the aircraft for granted and think that it is ok to fly on uncharged battery.

What happens is, he amount of volts needed to fly the aircraft are NOT based on the remaining charge percentage shown on the battery. The vehicles we drive have a alternator that will keep the volts at a safe point when running. If the belt breaks the alternator stops and the voltage level needed for the electronics to properly function drops below it's ok limit. That doesn't mean the battery is dead, it just means there are not enough volts on tap.

If the battery has a little age to it, then the cells are somewhat weaker making it extremely important for there to be a full charge before flight. Not enough volts....and down comes the aircraft.