Abstract: A vault for storing batteries underground, having glass fiber reinforced concrete body including a floor and vertical walls, and an insulated fiberglass top closure, and a method of storing batteries. Two conduits disposed in generally concentric fashion communicate between the interior of the vault and the external atmosphere. One conduit has a connector for connecting to a supply of pressurized nitrogen gas. The other conduit branches into two secondary conduits, each having a unidirectional check valve opening when a pressure differential between the interior of the vault is established relative to the external atmosphere. One check valve admits air to the vault and the other check valve allows air to escape to the external atmosphere. The vault includes an external support structure for supporting a davit in an operable position for lifting batteries from the vault.