Recently, when I press RTH button, my Mavic Pro is telling me "home point is too far", and give me 2 options, fly to "new home point" or "original home point. My Mavic is never more than 1 km away, usually within 500m, and height is like 300m.

First of all... where the hell is the new home point? Dynamic home point update is disabled for sure, so I don't understand where it gets the new home point from. I didn't want to try it out, since I might loss connection at that point by pure luck, and my drone fly back to Shenzhen (j/k)...

If I remember correctly, I never had it on my iPhone 8 Plus, but started getting this message on RTH after I switched to CS 5.5.

Anyone can tell me what trigger this option? Obviously my drone wasn't far away, I could fly back by sight if I wanted to.

Also what would happen if I choose new home point?

Any advice is very apprecaited.

Hi Macbrush, so sorry to hear about the issue. It happened after you switched to CS 5.5, right? To ensure the compatibility and the performance, you are recommended to use the mobile device on the compabile list of the Mavic pro: https://www.dji.com/mavic/info#downloads, thanks!

DJI Diana Posted at 2018-3-26 22:09
Hi Macbrush, so sorry to hear about the issue. It happened after you switched to CS 5.5, right? To ensure the compatibility and the performance, you are recommended to use the mobile device on the compabile list of the Mavic pro: https://www.dji.com/mavic/info#downloads, thanks!

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CrystalSky 5.5 should be compatible, right? Besides, could you tell me how is it trigger and where is the new home point set to?
Thanks

Macbrush Posted at 2018-3-26 22:12
CrystalSky 5.5 should be compatible, right? Besides, could you tell me how is it trigger and where is the new home point set to?
Thanks

Yes, the Crystalsky is compatible with the Mavic pro. It has been forwarded to our engineer for a look, meanwhile, could you please try the update and then check if it still happens? Thanks!

Your height might have something to do with the aircrafs assessment that the Homepoint was to far away.  Do you often fly at those heights and press RTH without issues?

Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations. It does so, so it can ensure a safe landing. When returning to home, it will first fly horizontally to above homepoint, and then descent.  This takes way more time then flying home manually, because you ussually ascend while you fly back. The RTH procedure does not take that in to account and therefore could or would calculate that you haven't got enough battery left to RTH.

I don't know for sure, but if you post your flightlog it probably tells more.

LoSBoL Posted at 2018-3-26 23:32
Your height might have something to do with the aircrafs assessment that the Homepoint was to far away.  Do you often fly at those heights and press RTH without issues?

Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations. It does so, so it can ensure a safe landing. When returning to home, it will first fly horizontally to above homepoint, and then descent.  This takes way more time then flying home manually, because you ussually ascend while you fly back. The RTH procedure does not take that in to account and therefore could or would calculate that you haven't got enough battery left to RTH.

Thanks, yeah I always use RTH disregarding the altitude, I will manually descend while the drone is coming home though. That might explain why the drone thinks the home point is too far, but I hope DJI can tell me what's new home point. Things like whether the drone will fly to new home point if I get disconnected is kind of worries me.

I'll get the flightlog and post when I get home tonight.

Macbrush Posted at 2018-3-27 00:35
Thanks, yeah I always use RTH disregarding the altitude, I will manually descend while the drone is coming home though. That might explain why the drone thinks the home point is too far, but I hope DJI can tell me what's new home point. Things like whether the drone will fly to new home point if I get disconnected is kind of worries me.

I'll get the flightlog and post when I get home tonight.

Yeah, I can understand your discomfort, I would have the same worries. I'm eager to hear what the conclusion will be.

Good thought process there LoSBol.

Macbrush Posted at 2018-3-27 00:35
Thanks, yeah I always use RTH disregarding the altitude, I will manually descend while the drone is coming home though. That might explain why the drone thinks the home point is too far, but I hope DJI can tell me what's new home point. Things like whether the drone will fly to new home point if I get disconnected is kind of worries me.

I'll get the flightlog and post when I get home tonight.

Hi Macbrush, there is a possibility that you did not refresh the home point success when you fly the drone, so could you try to fly the drone again and make sure the home point has been recorded success before the flying, the GPS should be in good status. If still no good luck, please export the flight records for the further assistance. Thank you in advance!

DJI Diana Posted at 2018-3-27 01:45
Hi Macbrush, there is a possibility that you did not refresh the home point success when you fly the drone, so could you try to fly the drone again and make sure the home point has been recorded success before the flying, the GPS should be in good status. If still no good luck, please export the flight records for the further assistance. Thank you in advance!

Thanks, I'll give it a go. But I doubt that was it, since as I select "original home", it returns to me.

LoSBoL Posted at 2018-3-26 23:32
Your height might have something to do with the aircrafs assessment that the Homepoint was to far away.  Do you often fly at those heights and press RTH without issues?

Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations. It does so, so it can ensure a safe landing. When returning to home, it will first fly horizontally to above homepoint, and then descent.  This takes way more time then flying home manually, because you ussually ascend while you fly back. The RTH procedure does not take that in to account and therefore could or would calculate that you haven't got enough battery left to RTH.

That makes clear sense.

LoSBoL Posted at 2018-3-26 23:32
Your height might have something to do with the aircrafs assessment that the Homepoint was to far away.  Do you often fly at those heights and press RTH without issues?

Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations. It does so, so it can ensure a safe landing. When returning to home, it will first fly horizontally to above homepoint, and then descent.  This takes way more time then flying home manually, because you ussually ascend while you fly back. The RTH procedure does not take that in to account and therefore could or would calculate that you haven't got enough battery left to RTH.

"Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations."

Is that mentioned in the manual, or is there a reference to it ? I have not heard of the critical battery level changing automatically, and I've never flown battery low enough to test out.

Aardvark Posted at 2018-3-27 04:07
"Because of the low descent speed of the craft, the critical battery level will jump from 10 to 20% when you fly at high elevations."

Is that mentioned in the manual, or is there a reference to it ? I have not heard of the critical battery level changing automatically, and I've never flown battery low enough to test out.

Hi Aardvark,

It was these two topics that triggered my memory when I read this topic. You can see the red critical batterybar taking up about 20% of the complete batterybar.
It made some sense to me that the craft would take safetymeasures and dynamically adjust the critical batterylevel considering the maximum descent speed is just 3 m/s, and with 300 meter altitude 10% would be cutting it awfully close to land safe.  I don't know if its documented in the manual though.


https://forum.dji.com/forum.php? ... dateline&page=1
https://forum.dji.com/forum.php? ... 6orderby%3Ddateline

LoSBoL Posted at 2018-3-27 04:24
Hi Aardvark,

It was these two topics that triggered my memory when I read this topic. You can see the red critical batterybar taking up about 20% of the complete batterybar.

That is something I never knew - thanks for the info though I never set my altitude above 120M but will be good for when I intend to fly around the mountain ranges here later in the year. Surprised that this is not in the manual.

Simmo1 Posted at 2018-3-27 01:06
Good thought process there LoSBol.

Looked smart eh? It was more of a remembrance thing though, from reading the topics mentioned above.

But lets wait what the flight logs say, I could be off by a mile.

A CW Posted at 2018-3-27 04:27
That is something I never knew - thanks for the info though I never set my altitude above 120M but will be good for when I intend to fly around the mountain ranges here later in the year. Surprised that this is not in the manual.

I never knew either! Untill I read those topics.
With the maximum altitude rules being around 120 meters in most countries, it wouldn't happen to those who fly beneath that. It looks like the majority of pilots respects these rules and therefore not much is to be read about the critical battery percentage being dynamic.

LoSBoL Posted at 2018-3-27 04:38
I never knew either! Untill I read those topics.
With the maximum altitude rules being around 120 meters in most countries, it wouldn't happen to those who fly beneath that. It looks like the majority of pilots respects these rules and therefore not much is to be read about the critical battery percentage being dynamic.

That's true - it's never crossed my mind to break the law with my drone.

LoSBoL Posted at 2018-3-27 04:29
Looked smart eh? It was more of a remembrance thing though, from reading the topics mentioned above.

But lets wait what the flight logs say, I could be off by a mile.

No I think you are on to something , but yes, before the hi 5's and champagne.....

A CW Posted at 2018-3-27 04:40
That's true - it's never crossed my mind to break the law with my drone.

I can't seem to even get my Air above 115 meters from sealevel, eventhough my limit is set to 120 meters. Now I wonder how that could happen.

LoSBoL Posted at 2018-3-27 04:24
Hi Aardvark,

It was these two topics that triggered my memory when I read this topic. You can see the red critical batterybar taking up about 20% of the complete batterybar.

" You can see the red critical batterybar taking up about 20% of the complete batterybar. "

Ahhh, good point the low power RTH would shift, as would be expected, but I hadn't realised that this would also pull up the critical landing value. I wonder what would happen if 'Smart RTH' (low battery RTH) were disabled ?

Aardvark Posted at 2018-3-27 05:12
" You can see the red critical batterybar taking up about 20% of the complete batterybar. "

Ahhh, good point the low power RTH would shift, as would be expected, but I hadn't realised that this would also pull up the critical landing value. I wonder what would happen if 'Smart RTH' (low battery RTH) were disabled ?

The craft would probably still account for that in its calculations of the critical battery level/landing.

But no way of telling without testing I guess.

Aardvark Posted at 2018-3-27 05:12
" You can see the red critical batterybar taking up about 20% of the complete batterybar. "

Ahhh, good point the low power RTH would shift, as would be expected, but I hadn't realised that this would also pull up the critical landing value. I wonder what would happen if 'Smart RTH' (low battery RTH) were disabled ?

On the other hand, the pilot of the first topic mentioned actively ignored the smart rth warning, which got him in to trouble with a forced landing at 20%.