Early RTH due to low battery

Return to home can be triggered automatically due to low battery. This article describes the parameters considered for triggering RTH and provides recommendations on optimizing the battery consumption.

In optimal conditions, RTH is automatically triggered at 37% battery. However, RTH can be triggered earlier so that a safe landing is always ensured. 

During the flight, it is estimated the amount of battery that the WingtraOne needs to safely return to the home point. For the battery estimation, the following parameters are taken into account. 

Absolute altitude (above mean sea level) of the home point

Increasing the absolute flight altitude, the density of the air decreases. In those conditions, the motors need more power to generate the thrust required for the flight, so the battery consumption increases. For more details about this parameter and what to do in order to ensure longer flight time, check this article.

Distance to home position

For mapping large areas, the drone flies far away from the home point. As the distance between the drone and the home point increases, the drone needs more battery for a safe return; therefore the RTH will be triggered at a higher level of remaining battery. To delay the low-battery RTH try the following:

  • if the terrain allows you, keep the home point closer to the mapping area
  • split the whole mission into a few smaller areas and change home point. Once you have mapped the first area, set the new home point near the second area, and so on.

For more details on how to map large areas, check this article.

The wind speed and direction

In windy conditions, the drone needs more power. Consequently, the battery consumption is increased. More energy is required so that the drone flies safely to home, so RTH is triggered at a higher battery percentage. For recommendations about flying in windy conditions see this article.

Transition altitude

By increasing the transition altitude, the drone spends more time hovering up or down and it consumes more battery therefore, to achieve a safe landing the RTH will be triggered earlier. For more details about transition altitude, how does it influence the RTH and what to do in order to delay it, check this article.

Minimum RTH altitude

This safety parameter has a similar impact on the flight time as the transition altitude. Loitering up and down for a longer period increases the required battery level. The impact of the transition altitude is clearly stronger than the RTH altitude. 

 

The biggest impact on battery consumption has the transition altitude. 

To extend the flight time, we suggest reducing the transition altitude,  taking always into account all obstacles near the home point. Reducing the time that WingtraOne will spend in hover during takeoff and landing leads to an increase in the total flight time.

Note that flights performed at high altitudes (above 1500 m AMSL) are shorter than flights performed at lower altitudes.