Tomasz, you don't specify whether your flying an ALTA 6 or an 8, but: The ALTA 8 manual, page 79, states: ALARM VOLTAGEThis adjusts the per-cell voltage warning level. Below this value, the Status Light will illuminate red and Orientation Lights will flash, indicating the flight packs are at a low state of charge. LAND VOLTAGE This adjusts the per-cell voltage limit below which ALTA 8 will begin to Autoland while flying in Height or Position Mode. Below this value, the Status Light and Orientation Lights will flash to convey the flight packs are at or below the land voltage. When flying in Manual Mode, the pilot will be alerted by the alarm indication, but Autoland will not be initiated. And the ALTA 6 and 8 manuals have the following table on Page 84 -- does it help? Andy Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. The Ground Is The Limit™ ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert