30% low battery warning?

[James474474]

By default the very scary low battery alarm starts at 30%. As a beginner I am never more than a few metres away by the time this alarm goes off. If it is kept close by is there a significant negative impact to changing the alarm point to 20% which is still quite high (in terms of charge)? That woukd equate to 2-3mins of extra flight time per battery...

 

[Bunny Too]

By default the very scary low battery alarm starts at 30%. As a beginner I am never more than a few metres away by the time this alarm goes off. If it is kept close by is there a significant negative impact to changing the alarm point to 20% which is still quite high (in terms of charge)? That woukd equate to 2-3mins of extra flight time per battery...

You should be fine, just exercise all stranded precautions.

 

[CanadaDrone]

20% would be the absolute minimum. It is not good for the batteries to be discharged anywhere near zero and you want that safety margin built in.

Also, if you're far away and a headwind picks up, you aren't making it back if you cut it too close even if the app is telling you that you will.

 

[HYRYSC]

20% would be the absolute minimum. It is not good for the batteries to be discharged anywhere near zero and you want that safety margin built in.

Also, if you're far away and a headwind picks up, you aren't making it back if you cut it too close even if the app is telling you that you will.

I am pretty sure that there is programming built in to not allow the batteries to be discharged during normal usage below the safety margin which would damage the batteries.

I am somewhat of a flashaholic and almost every reputable 18650 battery that I have used has a safety margin built in where I can run it until it basically shuts off, but it is still within the safety margin for discharge.

If a $20 battery has this built in, I would certainly think that a $80 battery would as well.

 

[DesJardins]

9% auto land... i’ve Not that 9% critical autoland once going long distance. Fun stuff

 

[CanadaDrone]

I am pretty sure that there is programming built in to not allow the batteries to be discharged during normal usage below the safety margin which would damage the batteries.

I am somewhat of a flashaholic and almost every reputable 18650 battery that I have used has a safety margin built in where I can run it until it basically shuts off, but it is still within the safety margin for discharge.

If a $20 battery has this built in, I would certainly think that a $80 battery would as well.

I'm sure there is protective circuitry built in to reduce the chances of a critical failure, but it is not good for lithium batteries to be run to almost zero. I also wouldn't want to be testing voltage safety margins with my $1000+ drone in the air, but that's just me. Best practice is always to return at 20-30%.

 

[HYRYSC]

I'm sure there is protective circuitry built in to reduce the chances of a critical failure, but it is not good for lithium batteries to be run to almost zero. I also wouldn't want to be testing voltage safety margins with my $1000+ drone in the air, but that's just me. Best practice is always to return at 20-30%.

I guess what I'm trying to say is it might be reading as 0% but it's probably not actually at true zero because it has a built-in safety margin.

I am pretty sure that I read even somewhere on DJI's paperwork to fully charge and then fully discharge the batteries to keep them in the best working condition.

 

[Lapeer20m]

9% auto land... i’ve Not that 9% critical autoland once going long distance. Fun stuff

Keep in mind that 9% autoland is based on altitude and other factors. Mavic May choose to autoland earlier than 9%.

To the ops specific question, 20% is fine as long as you are within vlos as defined by faa as you are within a minute or two of the takeoff point.

I leave mine set to 25%

 

[msinger]

If it is kept close by is there a significant negative impact to changing the alarm point to 20%

FWIW, that setting just allows you to adjust when the low battery and critically low battery notifications are displayed in DJI GO. It has no effect on the logic the aircraft is using to calculate the actual low battery and critically low battery levels.

This video explains it best:

 

[DesJardins]

Keep in mind that 9% autoland is based on altitude and other factors. Mavic May choose to autoland earlier than 9%.

Point being if you hit autoland it’s pucker time... I was at 400 feet and 1/4 mile out so no matter what if you’re going below 20% don’t do it unless you’re feeling froggy’ ;0)

 

[InvisibleName]

FWIW, that setting just allows you to adjust when the low battery and critically low battery notifications are displayed in DJI GO. It has no effect on the logic the aircraft is using to calculate the actual low battery and critically low battery levels.

This video explains it best:

That’s a really informative video!

 

[Kilrah]

DJI batteries indeed show 0% and shut themselves off way before hitting potential damage levels.

What you want to protect yourself from by not going close to that is a potential measurement error that causes the battery to unexpectedly shut off before reaching 0. 20% is my minimum.

 

[CanadaDrone]

I guess what I'm trying to say is it might be reading as 0% but it's probably not actually at true zero because it has a built-in safety margin.

I am pretty sure that I read even somewhere on DJI's paperwork to fully charge and then fully discharge the batteries to keep them in the best working condition.

I understand, but it's bad for them to even be really low even if it is not technically actually 0% (for example, if 0% was really 5% that is still not good). Unless 0% is really around 20% (which to my knowledge it is not) then in my opinion it's not a good idea to test it. Best practice and DJI recommendation is always to return home with plenty of battery, an absolute minimum of 20%. Sure if you're flying 100 feet away maybe you can push it to 15% without much harm but it's just not good for the longevity of lithium batteries to be run anywhere near zero.

Also DJI's batteries are not infallible. The more you push it, the greater the chances of something going wrong even if it's not supposed to. YMMV of course, I just think it's much better to be extra cautious and heed all manufacturer recommendations when flying a $1000+ drone.

I can also appreciate that it is only logical that you are given 100% battery so you must be able to fly to zero, that is a completely reasonable thought, it just isn't how it works unfortunately.

 

[Lapeer20m]

FWIW, that setting just allows you to adjust when the low battery and critically low battery notifications are displayed in DJI GO. It has no effect on the logic the aircraft is using to calculate the actual low battery and critically low battery levels.

This video explains it best:

Most importantly, it changes when the annoying beeping noise begins.