Abstract: A battery can comprises a casing and a vent formed on a interior surface of the casing, the vent being rupturable by a condition internal to a battery cell in which the battery can is employed. The vent is a roll-formed groove disposed on the interior surface such that a weakness is defined in the casing. Upon encountering a buildup of excessive pressure in the battery cell, the vent ruptures, thereby compromising the structural integrity of the casing and relieving the pressure. A method of forming a rupturable vent in a casing of a battery cell comprises positioning the casing adjacent to a tool such that a first surface of the casing faces the tool and biasing the casing against the tool to form a groove in the first surface. A method of forming a battery can comprises forming a casing and roll-forming a rupturable vent in an interior surface of the casing.