The operator of the unmanned aircraft system (UAS) reported that during a test flight, the UAS descended, delivered a package to the practice location, and began a vertical climb to return to the landing zone. During the vertical climb, the UAS registered a low voltage health alert and initiated an “urgent land maneuver.” During the maneuver, the UAS battery depleted to a point where it lost propulsive power, and impacted terrain, resulting in substantial damage to all 4 wings, and spar damage to the number 2, 3, and 4 wings. Postaccident review of the circumstances surrounding the flight by the operator revealed that an insufficiently charged battery had been installed on the UAS. The operator reported that there were no preaccident mechanical failures or malfunctions with the UAS that would have precluded normal operation.