P3 turned off and fell from the sky

[Oso]

Believe it. Because, I did it. Just to see how long I could fly with a battery that was 53% charged. Fired up my P3 lead it at a low hover & flew it slowly around at that hover level of 3ft. Flight lasted less than 2 minutes & it went into auto land.

Not to mention how many times it has been reported, and that DJI released a new FW just to address it. Hard to not believe it at this point.

 

[Helijoc]

Indeed too much jumping to conclusions about the cold. I fly mine all the time in much colder temperatures, sometimes to -20 F, and have had no issues (but I do always start with a fully charged, room-temperature battery). Sounds like it was in auto-discharge and would have happened in the cold or not. Always best to top off your battery before the flight just to ensure its not in auto-discharge.

How do you tell if your batteries are in auto discharge ? Mine are set to 10 days. Do they discharge over 10 days or at the end of 10 days? Often find myself topping off my batteries without actually using them for one reason or another. I always top them off by turning them on before plugging them into the charger. Curious if I will diminish the battery life.

 

[1st_time_flyer]

Not to mention how many times it has been reported, and that DJI released a new FW just to address it. Hard to not believe it at this point.

so has the new firmware actually fixed this issue then...

 

[Oso]

so has the new firmware actually fixed this issue then...

From following several of the "New Firmware" threads, it seems that people are still feeling it out. Some are seeing incremental slow downs in speed as the battery depletes. This is an effort to avoid the sudden voltage drops that have been shutting down Phantoms, and aligns with the release notes. Some are reporting no slow down in speeds. I don't think it has been definitively shown yet if the new FW fixed the battery management issue or not.

 

[JustinJ]

From following several of the "New Firmware" threads, it seems that people are still feeling it out. Some are seeing incremental slow downs in speed as the battery depletes. This is an effort to avoid the sudden voltage drops that have been shutting down Phantoms, and aligns with the release notes. Some are reporting no slow down in speeds. I don't think it has been definitively shown yet if the new FW fixed the battery management issue or not.

People are seeing different results because the firmware update relates to output power in "COLD ENVIRONMENTS" (ONLY!!)

Of those that have reported their finding so far - they're obviously in different "environments" / climates to each other.

(The update has nothing to do with limiting output power during the discharge / use of the battery)

 

[JustinJ]

How do you tell if your batteries are in auto discharge ? Mine are set to 10 days. Do they discharge over 10 days or at the end of 10 days? Often find myself topping off my batteries without actually using them for one reason or another. I always top them off by turning them on before plugging them into the charger. Curious if I will diminish the battery life.

Oh come on man.. stop being so lazy!

RTFM - page 4 of the battery doc explains very clearly..

(Personally, I have mine set to discharge after 3 or 5 days)

& continuous top-up will damage your battery performance / life!

 

[Oso]

People are seeing different results because the firmware update relates to output power in "COLD ENVIRONMENTS" (ONLY!!)

Of those that have reported their finding so far - they're obviously in different "environments" / climates to each other.

(The update has nothing to do with limiting output power during the discharge / use of the battery)

Hi Justin. Once you read more and find out that you are not correct in his case, I hope you'll go back and edit your post. Cheers sir.

 

[JustinJ]

Now I'm totally confused, you mean to tell me that if I stick a battery in my P3 that is at say 50% charged and I fly it aggressively causing the battery to go into what you call the 3.0V "danger zone" that it's MY fault??!!? I am not the OP of this thread but I find It very hard to believe that I can't fly my quadcopter with a 50% charge aggressively without it falling out of the sky........

Yes - that would be your fault!

For two reasons:

1) 50% charge in the battery (you are advised to use a fully charged battery)

2) flying aggressively (the P3 is a flying camera - not a racing quad)

If you are still finding it hard to believe - maybe go out & do "experiments"..

Basically, a pattern has been forming in certain situations...

(Thankfully, there are regular members that have recognised this & taken the time to share time & time again)

 

[JustinJ]

Hi Justin. Once you read more and find out that you are not correct in his case, I hope you'll go back and edit your post. Cheers sir.

I can more than accept my error (if I have made one??)

But I have read this directly from the release note:

"What’s New:1. In cold environments, propulsion output is automatically adjusted based on battery temperature and cell voltage. Horizontal and vertical speed is also decreased to avoid triggering battery protection"

What is my error please?

(As immediately after the number "1" it reads "in cold environments"

 

[ParsnipHysorter]

People are seeing different results because the firmware update relates to output power in "COLD ENVIRONMENTS" (ONLY!!)

Of those that have reported their finding so far - they're obviously in different "environments" / climates to each other.

(The update has nothing to do with limiting output power during the discharge / use of the battery)

It would be okay if indeed it only applied to "cold environments". As discussed on a different thread, I am flying mine in a relatively "cold environment" all winter here in Alaska and see performance degradation with this new firmware, I guess as expected. If I could expect my performance to return come summer I wouldn't mind so much, but it is disconcerting for me to note many others saying even at 70 F / 21 C weather they also see the same performance degradation I am seeing in my "cold environment". Maybe to DJI, 70 F is a "cold environment" too ?

 

[JustinJ]

It would be okay if indeed it only applied to "cold environments". As discussed on a different thread, I am flying mine in a relatively "cold environment" all winter here in Alaska and see performance degradation with this new firmware, I guess as expected. If I could expect my performance to return come summer I wouldn't mind so much, but it is disconcerting for me to note many others saying even at 70 F / 21 C weather they also see the same performance degradation I am seeing in my "cold environment". Maybe to DJI, 70 F is a "cold environment" too ?

I can understand why the output power would be limited in your situation..

& I agree with you that you should expect to see less restriction during the summer months etc.

I have conducted a number of flights since the update. Personally, I have not noticed any restricted performance (but I do not fly aggressively - on full sticks etc)

I can only comment on the update notes that state "in cold environments"..

It would indicate an error by DJI if output power restrictions are actually prevalent in all "environments".. as 70f/21c isn't a "cold environment"

 

[kirk2579]

Where are you getting your information from? You are an approved vendor, but is that an official response from DJI? That would be ridiculous for a rapid climb to suddenly drop a battery so low that it shuts off. The technology in these machines is amazing. To not be able to climb out at full throttle with even a 40% battery would have these things falling out of the sky steadily. Please verify if this statement you've made is an official statement from DJI?

I am going to guess from reading his posts for a year plus now the answer is experience and history and observation.
I am also going to guess he is an approved vendor on this site , which is NOT DJI related as well as DJI dealer.

I have seen seen P1 's and P2's react in similar way when flying with low battery.
Take my p1 when about 50%, If I push it up hard it will almost always react with red battery low indicator led, back it off and back to green, that tells me time to go home now!

also after flying P2 vision plus for a while you learn a lot about DJI batteries and issues...lol

good luck and have fun flying!

 

[msinger]

you mean to tell me that if I stick a battery in my P3 that is at say 50% charged and I fly it aggressively causing the battery to go into what you call the 3.0V "danger zone" that it's MY fault?

That's correct. And, it's also your fault if you misjudge the altitude and hit a tree. Flying your Phantom is only half the battle. You must also take the time to learn how it works.

 

[kphantom]

It would be okay if indeed it only applied to "cold environments". As discussed on a different thread, I am flying mine in a relatively "cold environment" all winter here in Alaska and see performance degradation with this new firmware, I guess as expected. If I could expect my performance to return come summer I wouldn't mind so much, but it is disconcerting for me to note many others saying even at 70 F / 21 C weather they also see the same performance degradation I am seeing in my "cold environment". Maybe to DJI, 70 F is a "cold environment" too ?

After reading a lot of threads on the new firmware upgrade and prior "sky fall" incidents, I think that cold makes the voltage drop of the battery worse when it is under heavy load such as when revving up the engines by throttling upward aggressively. When batteries are older or lower on charge the voltage also drops severely when under heavy loads. So what DJI seemed to do is monitor battery temperature and calculated voltage to change throttle load limits (decrease them) in times of low temperature and lower battery life (60% and lower perhaps). This would decrease the voltage drop and hopefully keep it above 12 volts (3 per each Lipo cell X 4 = 12v). I also hope they erred on the side of safety and eliminated the battery shutoff. Who cares about damage to a battery over time; this better than a crash that bricks a phantom and its battery!

 

[Carmelsteve]

I'm new to DJI, having been a 3DR pilot for the last year or two, but I'm totally baffled by DJI's approach to battery management. I get it that letting the cells get below 3 volts for minutes or hours can shorten life, but I've never heard of substantial damage from a cell going under 3 volts for a second or two, which is what happens during hard acceleration. And why doesn't it go into an auto-land or RTH? A shut-off can only result in a crash. Why try and save a little lifespan of a battery when you destroy the quad and possibly even hurt someone?

Really wish DJI used "dumb" batteries like the ones I've always used with other quads. I got to tell the quad what to do under different circumstances, even if that meant I might harm the battery a bit. But never had a quad fall out of the sky.

 

[msinger]

And why doesn't it go into an auto-land or RTH?

That's known as "critical low battery". At that stage, the Phantom is supposed to auto land at its current location. It seems whatever these pilots are doing is causing that to be skipped somehow.

 

[Carmelsteve]

Well, I suspect that for some reason, the main controller is shutting down the flight systems if a cell falls below 3 volts. Maybe it's a hard-coded issue. I'd hate to think that a shut-down is programmed in, no matter how low the voltage.

 

[RasterEyes]

Could it be that the system requires at least 3v to operate? That when dropping under that threshold it shuts down not to protect anything but because it can't remain on?

In any case it appears obvious to avoid dropping near 3v for the time being and to understand that taxing your bird can drop the voltage quickly.

Just to add, pushing against a high wind will also drain the battery. I was up in a light breeze and the wind started to get gusty... Just coming back to land was visually draining the battery quite quickly.


Sent from my iPad using PhantomPilots mobile app

 

[1st_time_flyer]

I have seen seen P1 's and P2's react in similar way when flying with low battery.
Take my p1 when about 50%, If I push it up hard it will almost always react with red battery low indicator led, back it off and back to green, that tells me time to go home

So when my battery when charged to 100% gets to 50% than I need to pack it up and quit flying?!?! I can't believe all of you find this is normal!!!!!


Sent from my iPhone using PhantomPilots mobile app

 

[msinger]

So when my battery when charged to 100% gets to 50% than I need to pack it up and quit flying?

Nope. You should be landing at around 30% or before the first battery cell reaches 3.3V (see more here).