At the end of my last flight this afternoon I found out what happens when the battery is low and the P4 decides it's time to go home. It just happened to be under a tree at the time.

The drone almost crashed at that time in the video clip. So please pay attention to the obstacles around next time and fly in an open area with reasonable altitude.

Exactly the same thing that happened to me, a while ago. See the attached link below, which also explains how to recover from the situation...... And how I got Banned from flying in and around my own propety.. :-)

http://forum.dji.com/forum.php?mod=viewthread&tid=40587

There really shouldn't be any reason for the aircraft to even go into low battery RTH. Users should have already landed when before the battery gets low. And when it gets the RTH warning you have plenty of time to cancel it anyways.
Also, for the first 10 cycles, you should only take the battery down to 50% to prolong the life of it.

That was a nice recovery by the P4 though.

Geebax Posted at 2016-3-30 12:50
That was a nice recovery by the P4 though.

Hi Tim, So is there/will there be a way to reduce the RTH altitude below 20m?  Especially for beginner mode it seems we (especially me) would like to have a lower RTH setting.  It is kind of scary when you are just toting around at low altitude trying to learn the flight dynamics and then it shoots up to 30m (default) to RTH.  Prefer it just comes back to me at 6-10 feet or so.

CitizenKane Posted at 2016-3-30 16:02
Hi Tim, So is there/will there be a way to reduce the RTH altitude below 20m?  Especially for begi ...

No ... because when RTH activates for real you probably won't be in a position to see your Phantom.
Because of this, the general idea is that your Phantom comes back at an altitude at which it's not going to slam into trees, shrubs, cars, people, buildings etc.

OK, I get that, but in beginner mode we are limited to a 30m radius.  My first flights were less than 10m radius but maybe I'm more conservative than most.  

CitizenKane Posted at 2016-3-30 07:35
OK, I get that, but in beginner mode we are limited to a 30m radius.  My first flights were less tha ...

"Prefer it just comes back to me at 6-10 feet or so."

It'll be more likely to hit people at those heights.  Don't forget, not everyone flies on perfectly level ground & the height is from the take off point.  This is even more important in beginner mode because it's more likely for a beginner to forget to check their surroundings & not adjust the RTH height to suit.

Agreed, but as a beginner I was/am practicing in a big open area where there isn't anyone around (to watch me crash).

but point taken.

DJI-Ken Posted at 2016-3-29 23:40
There really shouldn't be any reason for the aircraft to even go into low battery RTH. Users should  ...

I am interested in understanding the process of battery 'conditioning'.  Can someone provide some technical data as to why Phantom batteries must be 'conditioned'?

LiPo batteries are present in everything from smart phones to laptops and none require any special charging.  Why are Phantom batteries different?

https://en.wikipedia.org/wiki/Lithium-ion_battery#Conditioning

Thanks

DJI-Ken Posted at 2016-3-30 00:40
There really shouldn't be any reason for the aircraft to even go into low battery RTH. Users should  ...

Exactly, shouldn't have been in this situation in the first place, but the phantom 4 did handle the situation well.

DJI-Ken Posted at 2016-3-30 12:40
There really shouldn't be any reason for the aircraft to even go into low battery RTH. Users should  ...

Golly Ken, you would think something that important for the battery would be mentioned in the manual. I didn't see it. I'll read it it again.
From the time the bird stopped, rotated and rose into the branch was all the time I had to reach in through the holes of my sun shade, hit the cancel button and then swipe the middle of the screen. I guess I'm slow. Of course I knew it was getting close since I had gotten the 30% warning a minute or so before.

C'mon guys, I wasn't looking for admonishment nor complaining about anything. I just thought it was neat how the P4 recovered and didn't hit the ground. I'm coming from a couple Parrot drones that shut off completely and freefall if the rotors so much as tick a fly in the air.

dji-p3p1 Posted at 2016-3-30 12:26
Exactly the same thing that happened to me, a while ago. See the attached link below, which also exp ...

Yeah, I got indoor flight banned from the same authority after bouncing my AR.Drone 2.0 off the fireplace mantel a half hour after opening it up on Christmas morning. There were fake wreath flowers flying through the living room instead of pine needles. Those W.I.F.E. guys are tough to deal with sometimes.

spiderbot.sb Posted at 2016-3-30 19:20
I am interested in understanding the process of battery 'conditioning'.  Can someone provide some  ...

It just a general rule and I have been doing it for years.
My P3 Pro and batteries are a year old and one of my batteries has 60 something charges and still has 97% life left.

CitizenKane Posted at 2016-3-30 13:02
Hi Tim, So is there/will there be a way to reduce the RTH altitude below 20m?  Especially for begi ...

You can set the RTH to just land but make sure whatever you are flying over is flat ground.
But again, there really is no reason to reset the RTH height. You should be landing way before you get a low battery RTH.

dirtdroner Posted at 2016-3-30 20:36
Golly Ken, you would think something that important for the battery would be mentioned in the manu ...

No big deal, you just got very luck that it didn't crash and you had a $500 bill to repair it.
Anyways, just be careful and take your time and congratulations on your new Phantom.
I would suggest going into the academy section of the app and reading the entire 64 page manual and watching the tutorial videos. I promise you will be glad you did.

DJI-Ken Posted at 2016-3-30 08:43
It just a general rule and I have been doing it for years.
My P3 Pro and batteries are a year old ...

Thanks for that.

Do you have any technical evidence that battery conditioning is necessary?  The link I provided says it is an erroneous assumption.  I have never conditioned batteries on any of my various flying models going back 30 years.  My three P3 batteries have similar numbers as what you just stated, with one showing 95% and another 99%.

Were side-by-side tests ever performed by anyone?  Are there any technical test results anywhere that show conditioning is helpful in any way?

Battery conditioning is not supported by science, AFAICT.

Thanks

spiderbot.sb Posted at 2016-3-30 21:51
Thanks for that.

Do you have any technical evidence that battery conditioning is necessary?  The l ...

That is what I do and I believe it helps.
But go find a forum about lipo batteries and ask there. You may get all different opinions. I've done this for many years and I'll continue to.
How many charges do you have on the batteries that say 95% and 99%/

WoW! I never thought to use my P3P to prune my trees!

@DJI-Ken  Sometimes the RTH warning  does not give you NO TIme at all! As the Warning is sounding the bird is assenting!

Sonar sensor above maybe a simple addon to prevent this stuff from happening.  I really wish DJI had an open architecture on the phantoms to allow you to attach external custom and aftermarket peripherals.   

And this is why DJI needs to install sensors on top of the aircraft...as well and behind it and on both sides
Anyhow, just playing around a little. Nice recovery for sure.

SVTRay Posted at 2016-3-31 07:26
And this is why DJI needs to install sensors on top of the aircraft...as well and behind it and on b ...

Yes .. it's not right for DJI to  expect users to apply any thought to flying their Phantoms.
You shouldn't have to think at all.

63 and 65 respectively.

I ask a question about batteries and I'm told to go elsewhere.

DJI sells the batteries but a DJI representative tells me I need to go somewhere else to understand why he says we should condition batteries.

Nice.

Why is this not the place to ask about handling batteries?

I am not asking for opinions.  I am asking for technical data.

spiderbot.sb Posted at 2016-3-31 20:52
63 and 65 respectively.

I ask a question about batteries and I'm told to go elsewhere.

I have to agree. Though my thread didn't start out as a battery topic and this could be considered a highjack, my topic wasn't really a discussable one. It was just Wow, look at this. That it took a turn into battery conditioning as a result of my root cause being 'low battery' makes it relevant. I want my batteries to last as long as possible. They're expensive. Being told by the company that I could be doing something to harm them naturally begs an explanation of how to prevent that.

dirtdroner Posted at 2016-3-31 08:54
I have to agree. Though my thread didn't start out as a battery topic and this could be considered ...

Sorry for the hijacking.  Perhaps not everyone thinks so, but I think it's proper for courteous casual discussion, such as in a forum of users, to go wherever it happens to go.  There's always search if you're looking for something in particular and moving a discussion to another thread, and then referencing the original is a bit cumbersome.  I wouldn't have bothered except the question has been asked in other threads without response.

Perhaps I'll start a new thread.

Anyway, sorry.

No, no. My point was I don't think it is a highjack. I agree with you. Now that said, we probably would get more information from a separate thread just because the title would draw people based on the specific topic.

Ahh Grasshopper, It is only a bad experience if you did not learn anything.

spiderbot.sb Posted at 2016-3-31 07:52
63 and 65 respectively.

I ask a question about batteries and I'm told to go elsewhere.

      Spider, I dont think Ken was being rude , ( cultural language barrier, I think he is from china , a little more blunt )  I think he was saying that He does not know the exact answer and perhaps you could find more specific data on another forum. I , Like You, have been flying RC for close to 30 years.  I would always have my packs built by a fellow named SAL  from SR batteries, he was and still is great.  He built packs for some of the big boys NASA etc.  Anyhow he always told me to break in the packs to help balance the cells but more importantly to be able to spot a bad cell in the bunch.  By keeping the flight times low,  as well as Not pushing the batteries 100% on day one,  you get a better chance to find that bad cell and avoid catastrophe.  I also owned a West Mountain battery tester that would  give me more data then I could possibly use to help find problem cells .  My packs would last far longer than most other RC Pilots.  So I guess what I am saying is there may not be any Harvard Study on the benefits of  Only using 50 % of the battery and not  Pushing the limits for the first 10 cycles , but the empirical evidence suggest 's doing so will prolong the batteries and the aircraft's  longevity .   I am quite convinced that it works even though it is anecdotal .

- brother donnie

Donnie Posted at 2016-4-1 05:43
Spider, I  dont think Ken was being rude , ( cultural language barrier, I think he is from ch ...

" I dont think Ken was being rude , ( cultural language barrier, I think he is from china"

FYI .. Ken's from California

labroides@yahoo Posted at 2016-3-31 15:47
" I dont think Ken was being rude , ( cultural language barrier, I think he is from china"

FYI .. ...

Oh, gosh I heard they were all from China, Thus the Names- Ken, Tim , Amy .  As the matter of fact I once inferred this  and they he  not correct me, Maybe that was with another DJI member.  I believe you Lab, I really thought they were Chinese with"Westernized Names"


Thanks for the heads up -brother  donnie

spiderbot.sb Posted at 2016-3-31 20:52
63 and 65 respectively.

I ask a question about batteries and I'm told to go elsewhere.

I was referring you to search the internet about conditioning batteries because you will bet much more information on conditioning batteries from a lipo battery forum.
I was not trying to be rude but only to educate yourself on what other people do.
I condition all my batteries just because I've done it for years and I believe it helps.
So I was saying search the internet for a lipo battery forum and you can see what other users are doing.
I'm sorry if you thought I was being rude.

Donnie Posted at 2016-4-1 05:15
Oh, gosh I heard they were all from China, Thus the Names- Ken, Tim , Amy .  As the matter of fact  ...

It's ok Donnie
By the way, I sent you an email about your TB48's. Sorry it's not the news you'd like to hear.
Go ahead and start another thread and not respond in this thread if you want to talk about it.

CitizenKane Posted at 2016-3-29 23:35
OK, I get that, but in beginner mode we are limited to a 30m radius.  My first flights were less tha ...

If you are within 20 meters of home point,  the Phantom is supposed to just land in place.

Donnie Posted at 2016-3-31 13:43
Spider, I  dont think Ken was being rude , ( cultural language barrier, I think he is from ch ...

Thank you for the polite and well thought out reply.  Quite refreshing, actually.

I do not intend to argue but I would like to point out that a bad cell will be found anyway.  I am not opposed to using small amounts of a new battery at first, just to see what the numbers are.  Don't want a bad battery to ruin your day, right?

But 'conditioning' of LiPo batteries is not supported by science AFAICT.  Most of what's on the net is 'common knowledge' with little actual data.  The wiki I posted above (thanks to Aardvark) says conditioning is an improper association with non-LiPo battery chemistries.

Until someone shows that conditioning is chemically necessary by providing data such as a side by side comparison, or some advanced chemical analysis, I won't bother after the first couple flights.

BTW, DJI-Ken might live in sunny CA but based upon his English sentence structure, he is from China.  He may not even be a he.    The Chinese folks I've worked with are highly intelligent and hard working but they all took American sounding aliases.  I appreciate the sentiment but in the interest of better integration, I always thought it would be nice to know the proper pronunciation of someone's name.

DJI-Ken Posted at 2016-3-31 17:23
I was referring you to search the internet about conditioning batteries because you will bet much  ...

I didn't think you were being rude.  I thought you were avoiding the question.  ;)

My research has not provided much evidence promoting conditioning of LiPo batteries.  Older types of rechargeables apparently benefited from conditioning but LiPos not so much.

http://batteryuniversity.com/lea ... thium_ion_batteries
http://batteryuniversity.com/lea ... ium_based_batteries

Neither of the above promote or even mention conditioning.  All mention of conditioning of LiPo batteries that I found on the net was anecdotal.

Anyway, thanks for your efforts in this forum.  It is appreciated!

spiderbot.sb Posted at 2016-4-2 00:00
Thank you for the polite and well thought out reply.  Quite refreshing, actually.

I do not intend ...

"DJI-Ken might live in sunny CA but based upon his English sentence structure, he is from China.  He may not even be a he"
Wrong on both  guesses.