Hello All,
    I thought I would inquire here as I seem to be somewhat confused.  As I understand it, the battery level indicator displays length of flight time as well as battery status.  It is color coordinated with the following statuses: green - sufficient battery, yellow - low battery, and red - critical low battery.  Additionally, it also has a little H symbol that marks point of safe return.  The H adjusts automatically based on current altitude and distance from home point.  Now.... here is where I'm confused as the manual clearly doesn't elaborate beyond the following:

RTM and Low Battery RTM
When the RTM button is pressed, the aircraft rises to the RTM altitude you set and simply returns to home (unless your 65 feet from home point, in which it just descends and lands).  When Low Battery RTM is triggered, the aircraft has decided that it has to safely return to home because the current altitude and distance has reached a threshold where it needs to land safely due to remaining battery power left.  The GO App warns you that if you don't respond in 10 seconds, it will execute RTM (also causing it to not gain in altitude but land where it's at if it's 65 feet from your home point).  


The manual doesn't talk about these at all......

Low Battery and Critical Battery Settings
I originally forgot what the low and critical battery settings were set to, but it was my understand that based on what these values were set to, the aircraft would simply warn you of lower battery at your lower battery setting and then land the aircraft at your critical battery setting (meaning land where it's at without any choice but to maneuver it out of the way of obstacles as it descends)


And here lies the confusion........

1.  Am I correct in thinking that no matter how your RTM is triggered (low battery, failsafe, or simply pressing the button), the aircraft will land where it's at if your within 65 feet of your home point?
2.  If the H symbol (or point of safe return) triggers Low Battery RTM before your low battery warning setting, how does the low battery setting help you?(meaning you've just received a RTM warning that will happen in 10 seconds, so the lower battery warning you set doesn't matter anymore)
3.  If your aircraft is automatically landing, whether it's RTM, Low Battery RTM, or Critcal battery, can you still maneuver it to a safe spot as long as it doesn't have to do with raising altitude?
4.  Am I correct in thinking that if you are more than 65 feet from your home point, your aircraft will rise to your RTM altitude setting before returning home regardless of how RTM is triggered (low battery, failsafe, or simply pressing the button)


Here's my experience with low battery return to home.....

On my third battery change, the low batter RTM triggered before my low battery setting.  I was ok to watch it land in 10 seconds.  However, 10 seconds went by and nothing happened.  I then pressed "return to home" to agree to the 10 second warning.  The aircraft descended after a few more seconds (as it was already within 65 feet from my home point, so it didn't ascend before coming back and descending).  This gave me the opportunity to see what would happen if I needed to maneuver to a new spot.  I raised up on the control stick, the aircraft seemed to insist on landing (kind of bobbing like a yoyo), and I determined that I should just let it land since it was fighting so much.  After releasing the control stick, the aircraft came to an unusually hard landing.  Nothing was broken and all seemed well, but it was very concerning.  Why did such a hard landing occur if I'm supposed to be able to maneuver it to a safer spot in times of need?  Anyway, I probably won't be trying that again, but it was a good opportunity to test and see how it behaves in an emergency situation.

Please advise as I would really like to understand all of this.  My main concerns are understanding if my thoughts are right and how to best set everything.  As of right now, I feel like I can't really depend on the low battery setting.  If the low battery RTM coincidently jumps in front of my low battery setting, it does me absolutely no good.  Additionally, I suspect the 10 second warning message that displays when low battery RTM initiates isn't as stable as it should be.


And just a little more info to add:  Firmware at 1.9.1.30 with all relevant updates to GO App.  Low battery setting was set at 20% and critical battery setting was set to 15%.  Also, I understand it's arguable that I could be right at my "safe point of return" that the H marks at the battery level indicator, yet still not reach my low battery setting (meaning low battery RTM triggers before my low battery setting).  However, based on my experience above, I was about 50 feet from the aircraft when the low battery RTM triggered.  It seems that it was a little premature and should have come after my low battery setting (after all 65 feet seems to be the threshold for being within your RTM bubble where gain in altitude is not needed).

You are much better off flying in a manner where you land safely in a controlled way with sufficient battery capacity to avoid any / all of the app functions.
They are a constant source of issues / crashes posted here.

YMMV, but I set the low battery warning at 30%, am well and truly on course back to land at that stage and am on the ground with a minimum of 25% remaining.
This protocol came about from the earlier issues we were having with battery levels being mis-reported and dropping to single figure percentages in seconds.

Set your low battery warning @ 30%  to 35%  and your critical battery @ 10% .
Common sense of your flight time, your battery %,  your birds distance from the rc, wind direction and speed should all dictate your appropriate  action to return home before your bird hits 10% and  lands itself in a bad place.
Just be aware of where your bird is at the 30% warning and think about when you should return home to land.
I was flying the first phantoms this way which had no warnings or auto landing settings,
so I've always watched my battery % value and used the 30 % mark as a good safety net and haven't lost one of my three
birds yet in over three years....happy landings !

I appreciate the advice.  I mostly want to confirm my understanding of what I wrote above.  If my understanding isn't right, of course I will have problems managing battery against the functions.  In any case, there's s difference between low battery RTH and critical low battery.  My problem seems to have stemmed from low battery RTH and not critical low battery.  I know this because my battery was still above my critical setting when it landed.  Additionally, you can't really dodge the low battery RTH function if the cancel in 10 seconds doesn't work.  The only thing you can do is try to land before it triggers, and as you already know, you don't determine when this triggers.  The aircraft determines when this triggers.  I doubted why it even triggered in the first place due to how close the aircraft was to me (roughly 50 feet). The altitude wasn't any more than about 15 to 20 feet off the ground.

Right then,   Another one of  the auto RTH features is supposed to take the inspires Distance from the rc controller,  the Flight Battery's Remaining % to determine the time left to safely return home and land,  ( especially if your flying at great distances from the RC Controller )
There is a warning on screen that allows the pilot to cancel RTH .
Sounds like your bird did this not to far away or just started landing at critical % or ?? Really not sure why it would land above the critical battery warning %  although your margine between low% and critical% was only 5% and looks like it probably did hit critical which at that % separation could drop very suddenly unexpectedly !!
Think the only way you'd be able to defeat the feature is to turn off the RTH feature in settings altogether.  Not a good idea maybe !! Fly Away.......or land away
Anywho, I've flown my inspire for 16 months, I use the features and they work as they were intended to so far without a mishap yet. Low battery @30% critical @10% At 30% start thinking of returning to the LZ.   never get distracted from that battery % when it's lower !!  Don't sacrifice your investment for that last shot as the battery goes to low to get home !

Do you fly over water ? Well .... I do and i use a margine of  battery safety.  Good photo ops to you

Dave/M Posted at 2016-7-10 11:59
Right then,   Another one of  the auto RTH features is supposed to take the inspires Distance from t ...

It did occur to me that there was only a 5% difference between the two, and perhaps it was too close for the aircraft to handle the appropriate action before thinking it was in critical.  I'll try a larger gap like 10% critical and 25% low.  I don't really want to set the low to 30% as it seems I'm sacrificing too much just to get the indicators to function as they should (granted I'm probably only getting an extra minute or so, but I think you get the point).  I seem to recall having them originally set at 15% critical and 25% low and not having too much of a problem.  In any case, this aircraft seems to land very hard if you maneuver it during a low battery RTH.  I don't think it should land that way.  I seem to recall others noting the same here and there.  Has this ever happened to you?


Just a quick edit:After reviewing my log, the aircraft went from low to critical low in 50 seconds...... so a 5% difference between low and critical settings roughly equals 50 seconds.  However, within those 50 seconds, 10 of those seconds were taken up by low power RTH.  Unfortunately, RTH never triggered even though I waited the 10 seconds out and even though I eventually pressed the button to agree to let it do it in 10 seconds.  At the 50 seconds mark, it did indeed go into critical power and try to land.  It was at that point I gave it some counter acting throttle to test for maneuverability.  The aircraft fought it so much that I simply let go of the stick and then it landed rather abruptly and hard.  The battery still had 14% battery life when it did so.  I still don't think it should land hard as it's in control of it's landing.

I would agree auto land seems a bit to harsh on touch down, mine didn't when new but I've noticed when I run a test of RTH it's pretty harsh at touchdown.. Yesterday tested RTH and I just gave the left stick a little gas upon landing and she set down gently, but if yer down on power and its in RTH I've noticed you have to over control or throttle up to keep it in the air... almost lost a phantom one day catching it as it just lost power at the shoreline over saltwater with epic footage onboard ... When I do the battery drain down I'll fly around my yard then when it hits critical I'll cancel the landing and hover about a foot or so off the deck and apply left stick throttle to keep her up until I'm at 5% and land.. by the time I reach the battery and shut it down it ends up at 3% or less which is good for resetting  the battery's internal memory.  Just time and fooling around a little in close proximity flying and looking back at my flight log has helped me some,  I believe it's best to not over think some things and just keep doing what works best for the individual.  It's beer:30 o'clock now

Dave/M Posted at 2016-7-10 15:02
I would agree auto land seems a bit to harsh on touch down, mine didn't when new but I've noticed wh ...

The landing was quite harsh.  Perhaps I should have slowly let go of the stick rather than releasing all together, but I had never seen it done before, and there are no warnings of this.  I looked the aircraft over to make sure all was ok.  It seemed to be in good shape, and even the orientation of the legs (looking at the propellers) still looks good.  I was a little worried it might knock the aircraft out of alignment with such harsh landings.  It's probably made better than I think, but I don't like to see this happen.  What are you thoughts?  Probably ok?

DJI,
   Can you add any clarity to my interpretation of what I described in first post?  I'm now understanding how quickly the battery can drop 5% in only 50 seconds of time.  This is also why most people probably set their low battery setting to 30% and the critical battery setting to.... (I believe it's 10% or the lowest setting).  They're probably buying time for a safe landing that doesn't cross into critical battery setting.  The difference between 10% and 30% is only 4 minutes.......   4 minutes to land or get forced to land.  Worse yet, if your critical power setting allows people to use a setting of 10% and the aircraft can't land in 2 minutes........   that would be a tragedy.

No input from DJI at all?!?!  

If you've flown electric rc airplanes ever you'll know that 50 seconds at 10% or 4 minutes at 30% are huge  in flying time to either get landed or fly back from distance to get landed.
And with an rc airplane it's not coming home on its own to land safely either, You fly it in !
Ask any decent RC pilot if battery % and flight time are important to be aware of
If you've flown rc aircraft much you should then understand the importance of battery % usage and what's left for safe operation in any given flight situation.
The battery safety set up dji has added does work well and is there for you to adjust as you please or not, the feature Did save my inspire on one occasion from my own distraction while filming, trying to get those final seconds of footage..
Adjust your safety margins as you like then...Try to not over think it.

I was really hoping DJI would make an official comment on my analysis.  It's not that I don't have an understanding of proper battery monitoring.  But you have to admit that the manual does get rather vague, and it leaves a lot to interpretation.