We were flying an inspection of a section of power line. From the starting point I flew in reverse motion to follow the line to the end point. Near the midpoint of flight, the sensor requested a yaw motion. I finished the mission, with 32% left on my batteries. I started home, not realizing my perception of the drone orientation was not correct. When I moved to come home, the motion was in an unexpected direction and I lost sight of the craft. Knowing I was at the max of 400 ft AGL and well above any obstacles I used the distance from home in an attempt to return home. The batteries hit 20% which was our minimum setting. I was unaware the craft started descending when the batteries reached the minimum setpoint. I hit the return home button, the craft continued to descend into a tree approximately 1700 ft from my launch point.