Why RTH was activated and one more question

[Mladen Matković]

the return height would typically be 40m or 120 ft to clear any trees or pylons in the area ,and because the OP was walking close to the drone he was still more than the 20m from home point so the drone would ascend to the RTH that he had set, if he had been near to the home point it would have just tried to land

RTH was set to 38m, distance from home point 103m, RTH triggered at 11,9 m, RTH altitude about 1.6 m. No wind at all.

 

[Thomas B]

I am not sure, but assuming there is not a fixed level to trigger the RTH on low battery, I can imagine that things as distance and wind (at flight level, not at the ground) may be parameters included in the process.

But there is.... 20%, not modifiable in settings.

 

[Mladen Matković]

Decided to recreate event,
RTH height 55m.
Home point taken, walk away to 34.2 m at 2.4m altitude(sonar). RTH was activated at 21% battery remaining and at home distance of 34.2m.
RTH started climbing to 3m when left stick was engaged.
Left stick down, slowly going down to 0.7m from my hand.
When hand was sensed, mini ascends to 2.7m with left stick permanently down.
Then again goes down and when sensing hand, jumps to cca 2.7m.
Pattern is repeating. Mini won't land when in RTH and left stick down. When sensing hand (obstacle), goes up for 2m then slowly descents.
Nice to know.