A pressurized underground enclosure includes a battery venting system having a battery within a battery box in a sealed enclosure. A first pipe is fluidly connected to the battery box and an ambient atmosphere and includes a vacuum generator for reducing a pressure in the battery box. A second pipe is fluidly connected to the battery box and the ambient atmosphere and includes a one-way valve permitting airflow to the battery box and precluding airflow from the battery box to the ambient atmosphere. The enclosure includes a scissors lift including scissor linkage units having arms pivotally connected at terminal ends and at central positions. The scissor linkage units are moveable from a retracted to an extended position by pneumatic cylinders. The internal pressurization of the enclosure is selectively released and locking mechanisms are retracted before a rack of the scissors lift is extended through an opening of the enclosure.